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This study investigates the attachment ability of harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), focusing on the synergic action of opposite legs, the anisotropy of adhesive organs and sexual dimorphism. Contrary to expectations, experiments showed that beetles with fewer legs sometimes exhibited higher attachment forces, challenging the hypothesis that collective leg action enhances attachment. This result is attributed to differences in experimental set‐ups, where our centrifugal method highlighted the importance of pad orientation relative to external forces. The anisotropy of adhesive pads, characterized by the directional dependence of adhesion and friction, significantly influenced attachment performance. Results demonstrated that inward‐oriented legs enhanced attachment due to lower peeling angles, whereas outward orientation reduced effectiveness. Sexual dimorphism was evident in the structure of adhesive pads, with males possessing discoidal setae on fore‐ and midlegs. No significant difference in attachment was observed between intact males and females on smooth surfaces, although ablated males sometimes showed higher forces due to the presence of discoidal setae. These findings underscore that attachment strength in H. axyridis is not solely dependent on pad area but also on the orientation and anisotropic properties of adhesive organs, as well as the specific role of sexual dimorphism in leg morphology. [ABSTRACT FROM AUTHOR]

Understanding causes of insect population declines is essential for the development of successful conservation plans, but data limitations restrict assessment across spatial and temporal scales. Museum records represent a source of historical data that can be leveraged to investigate temporal trends in insect communities. Native lady beetle decline has been attributed to competition with established alien species and landscape change, but the relative importance of these drivers is difficult to measure with short‐term field‐based studies. We assessed distribution patterns for native lady beetles over 12 decades using museum records, and evaluated the relative importance of alien species and landscape change as factors contributing to changes in communities. We compiled occurrence records for 28 lady beetle species collected in Ohio, USA, from 1900 to 2018. Taxonomic beta‐diversity was used to evaluate changes in lady beetle community composition over time. To evaluate the relative influence of temporal, spatial, landscape, and community factors on the captures of native species, we constructed negative binomial generalized additive models. We report evidence of declines in captures for several native species. Importantly, the timing, severity, and drivers of these documented declines were species‐specific. Land cover change was associated with declines in captures, particularly for Coccinella novemnotata which declined prior to the arrival of alien species. Following the establishment and spread of alien lady beetles, processes of species loss/gain and turnover shifted communities toward the dominance of a few alien species beginning in the 1980s. Because factors associated with declines in captures were highly species‐specific, this emphasizes that mechanisms driving population losses cannot be generalized even among closely related native species. These findings also indicate the importance of museum holdings and the analysis of species‐level data when studying temporal trends in insect populations. [ABSTRACT FROM AUTHOR]

This 4‐year study (2018–2021) aimed at investigating the effects of flowering areas inserted at the margin of soft wheat fields (Triticum aestivum L.) in comparison with spontaneous field margins. The action formed part of a multidisciplinary initiative promoted by the Barilla food company, aimed at promoting the sustainable production of soft wheat.Specific aims were to study the effects of flowering areas on (i) the abundance and species richness of insect pollinators, including wild bees, syrphids and butterflies; (ii) the levels of wheat aphid and bug infestations and (iii) the assemblages of biological control agents of aphids (coccinellids and aphid mummies as a result of parasitization).Insect surveys were carried out on 61 wheat‐growing farms located in Northern Italy. Insect pollinators were sampled on all farms, whereas wheat aphids, wheat bugs and aphid biological control agents were investigated in a sub‐sample of 20 farms.Results generally indicated a positive impact of flowering areas on multiple taxa in comparison with spontaneous field margins. The abundance of pollinators and coccinellids was significantly enhanced by the flowering areas. Aphid mummies showed an interaction between strategies and distances with more mummies at 5 m in wheat plots close to flowering areas and at 50 m in the plots close to spontaneous field margin (control).Flowering areas were validated as an important tool for promoting beneficial taxa in agro‐ecosystems. However, the successful establishment of this ecological infrastructure was suggested to rely on several factors, which included both the selection of suitable flowering plant species and the implementation of appropriate management practices. [ABSTRACT FROM AUTHOR]

Lady beetles (Coleoptera: Coccinellidae) are important biocontrol agents that are considered generalist predators, although some tribes, such as Scymnini, are specialized in predation of sucking pests, such as mealybugs, aphids, and whiteflies. However, prey preference or pre‐imaginal conditioning may occur as coccinellids are subjected to large‐scale rearing. Thus, predator–prey interaction may be an outcome of conditioning to prey stimuli. To evaluate possible pre‐imaginal conditioning, population lines were created for the lady beetles Cryptolaemus montrouzieri Mulsant and Tenuisvalvae notata (Mulsant), each fed for at least eight generations the mealybugs Ferrisia dasylirii (Cockrell) or Planococcus citri Risso (Hemiptera: Pseudococcidae). Next, the behavioral response of these coccinellids was measured in arenas treated with prey volatiles or footprints, regarding walking time, walking speed, walking distance, and residence time. Finally, food preference between prey species was measured in laboratory and semi‐field conditions on infested cotton plants. Conditioned coccinellids responded similarly to volatiles released by either prey species offered. Furthermore, there were no changes in predator behavior towards footprints of either prey species. Both predator species consumed more P. citri in all tests, regardless of rearing prey indicating no pre‐imaginal conditioning. These results suggest that rearing prey may not affect the predator behavior, and both coccinellid species are effective in the biological control of mealybugs. [ABSTRACT FROM AUTHOR]

Multitrophic interactions are common in nature and play a major role in modulating life‐history traits in predatory insects. The sequestration of chemicals and the transfer of nutrients from one trophic level to a higher trophic level have been reported previously. However, the effect of cannibalism, which is prevalent in the food chain, has not been explored yet. In this study, we hypothesised that the varying nutritional condition of the victim would significantly influence the life‐history traits of adult Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae). To test this hypothesis, we provided fourth‐instar individuals with first‐instar victims of varying nutritional quality for cannibalism. To create victims of varying nutritional quality, first‐instar victims were fed on high‐quality aphids [Aphis craccivora Koch (Hemiptera: Aphididae)], low‐quality aphids (Aphis nerii Boyer de Fonscolombe) and conspecific eggs. The cannibalistic groups were tested against the control group, in which the fourth instars were provided with their natural prey, A. craccivora. Our results revealed a significant difference in the consumption of prey by the fourth instars between the diet groups, with the control group consuming the most prey. The developmental duration of fourth instars was not significantly influenced by the victims' diet or the amount of victims cannibalised. Furthermore, neither the victims' diet nor the amount of victims cannibalised affected the mating (time to commence mating and copulation duration) and reproductive parameters (egg viability and fecundity) in M. sexmaculatus. Cannibalism here might have compensated for the low‐quality victims, resulting in insignificant effects on the life‐history traits of M. sexmaculatus. Otherwise, given the short duration of the first instars and their potentially limited ability to sequester significant amounts of plant allelochemicals, it is possible that their diet did not affect the development, mating and reproductive attributes of the cannibals. Thus, the use of higher instars as victims may yield substantially different outcomes. [ABSTRACT FROM AUTHOR]

Long‐term experiments are critical for understanding ecological processes, but their management comes with unique challenges. As time passes, projects may encounter unavoidable changes due to external factors, like availability of materials, affecting aspects of their research methodology. At the Kellogg Biological Station Long‐Term Ecological Research Site, one of the many National Science Foundation‐funded long‐term research stations, a three‐decade project recently experienced a supply‐chain‐induced change in insect sampling methodology in their lady beetle observation study. Since 1989, lady beetles (Coleoptera: Coccinellidae) have been sampled weekly over the growing season using yellow sticky cards. In 2021, the original sticky traps were discontinued by the manufacturer and replaced with a similar, but not identical trap. We conducted a 3‐year study while the new traps were phased in to examine how the trap change would impact the observed biodiversity patterns at the site. We examined community metrics and individual taxa captures to examine within‐year and between‐year differences in performance between the card types. Overall, we noted several small but statistically detectable differences in capture patterns between the two trap types. After accounting for other sources of variation, we observed a difference in Shannon diversity of insects captured on the two card types, but not richness or abundance, for the overall insect community. Yet, these differences were dwarfed by the magnitude of difference observed between years within card types. For individual taxa, similar patterns held: between trap differences could be detected statistically, but the number of differences in capture rate between trap types was less than the number of differences observed for the same trap, between years. Thus, we conclude that while subtle changes in methodology could impact data produced in long‐term experiments; in this case, the magnitude of this change is smaller than other factors such as time and plant treatment. However, if sustained changes in the capture rates of focal taxa are observed, future data users may use our observations to specifically quantify and correct for these shifting patterns related to the protocol change. [ABSTRACT FROM AUTHOR]

Coccinellids (Coleoptera) are important natural enemies of pests in agroecosystems. However, worldwide, native species face several threats, including landscape simplification, biological invasions, and climate change. In Central Chile, one of the global biodiversity hotspots, coccinellid communities are very diverse and are composed mostly of native species, which are most common in less disturbed habitats. In alfalfa fields, native coccinellids play a crucial role in the biological control of aphids, even when they are less abundant than exotics. However, in the last 2 decades, native species in this crop have declined in abundance and diversity. Our long‐lasting field and laboratory studies have shown that this decline is associated with: (1) the invasion of Harmonia axyridis (Pallas), which has superior competitive abilities and escapes more from parasitism; (2) the simplification of agricultural landscapes, loss of natural habitats, and urbanization; and (3) increasing environmental temperatures and decreasing precipitation. The decline in native coccinellid populations has resulted in a loss of taxonomic and functional diversity of assemblages, which may jeopardize biological control. Alfalfa fields and natural and semi‐natural habitats may offer an opportunity for the conservation of native coccinellids in agricultural landscapes. Such conservation might be achieved with better management of alfalfa fields and surrounding areas. [ABSTRACT FROM AUTHOR]

Regeneration has been a topic of interest across a range of taxa for centuries, and arthropods are no exception. Trade‐offs associated with regeneration are likely to involve the reallocation of resources away from other metabolic activities such as growth, development or reproduction. This might be reflected in costs to some developmental traits of the organism, despite regeneration being advantageous. These associated costs might also differ with the stage of injury or amputation. Here, we hypothesise that the extent of regeneration and trade‐offs associated with it may be stage‐specific. To test this hypothesis, the right forelimb of four larval stages of the ladybird beetle Cheilomenes sexmaculata (Fabricius) (Coleoptera: Coccinellidae) was amputated. Amputated individuals were reared until adulthood, and all developmental transitions were recorded. Regenerated legs in all the treatments were smaller than the controls, which did not experience the amputation, and the regenerative potency of early larval stages was higher than that of late larval stages. Limb regeneration caused delays in post‐amputation developmental duration in all the treatments, increasing their total developmental period. The length of the unamputated left foreleg as well as the wing and antenna size were also reduced in regenerated beetles, showing some internal trade‐off. However, there were no significant differences observed between regenerated and control adults in their fresh body weight and body size. Thus, limb regeneration depends upon the stage of larval development at which the amputation was performed. Amputation also affects the development of other appendages. The delay in normal beetle development might have been observed because of extra resource requirement, their allocation as well as reprogramming of the expression of some genes during regeneration. [ABSTRACT FROM AUTHOR]

Understanding of functional responses (i.e., changes in predator feeding rates with prey density) of key predators to different crop pest stages is critical to strengthening biological control, particularly in view of climate change and temperature variation. We investigated prey preferences of Coccinella septempunctata L. (Coleoptera: Coccinelidae) to egg and larval stages of a key brassicaceous pest of canola (Brassica napus L., Brassicaceae), the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae). First, laboratory choice and no‐choice bioassays tested the hypotheses that C. septempunctata accepts and differentially prefers two prey developmental stages (eggs and larvae). Then, C. septempunctata larvae and adults were exposed to six densities of P. xylostella eggs over 24 h in functional response bioassays that determined the number of eggs consumed. Finally, the functional response bioassays were repeated with larval prey and extended with three temperature regimes: 10, 22 and 32 °C. In both choice and no‐choice assays, C. septempunctata adults and larvae consumed more P. xylostella larvae than eggs. The functional response of C. septempunctata depended on predator developmental stage and temperature, with reduced handling time and increased attack rates and consumption under warmer conditions. At 10 and 22 °C, the functional responses of both C. septempunctata larvae and adults were of Type II, i.e., rates of prey consumption increase at decelerating rates and then plateau with increasing prey density. Our study demonstrates that both larvae and adults of C. septempunctata can consume high numbers of eggs and early instar P. xylostella larvae; these responses are temperature‐dependent with increased consumption rates at higher temperatures. This may lead to improvements in management of P. xylostella in canola. [ABSTRACT FROM AUTHOR]

Dactylopius spp. produce carminic acid as part of defence against predation. The average carminic acid concentration varies depending on the species, e.g., for prickly pear cochineal, Dactylopius opuntiae (Cockerell), and cochineal, Dactylopius coccus Costa (Hemiptera: Dactylopiidae), it is 3–5 and 19–25%, respectively. Generalist predators such as Laetilia coccidivora Comstock (Lepidoptera: Pyralidae) and specialist predators such as Leucopis bellula Williston (Diptera: Chamaemyiidae) and Hyperaspis trifurcata Schaeffer (Coleoptera: Coccinellidae) require detoxification mechanisms, which could be provided by gut bacteria. We determined the diversity of gut‐associated cultivable bacteria in these three predators and their ability to metabolize carminic acid. The bacteria were identified morphologically and by partial sequencing of the 16S rRNA gene. In vitro assays were done to determine their ability to metabolize carminic acid. The greatest culturable bacterial diversity was found in L. coccidivora larvae and H. trifurcata adults, followed by H. trifurcata larvae. The lowest diversity was found in L. bellula larvae. DNA sequencing revealed the presence of Bacillus cereus Frankland & Frankland, Enterococcus gallinarum (Bridge & Sneath) Collins et al., and Enterococcus casseliflavus Collins et al. in L. coccidivora larvae, Enterobacter spec. in larvae of H. trifurcata, Lactococcus lactis (Lister) Schleifer in adults of H. trifurcata, and Staphylococcus spec. in larvae and adults of H. trifurcata. Bacillus pumilus Meyer & Gottheil was only found in L. bellula larvae. In vitro assays showed that all isolates evaluated could metabolize carminic acid, suggesting they play an important role in the predators' ability to metabolize carminic acid. Presence of E. gallinarum, which had the most efficient metabolism of carminic acid, might allow L. coccidivora to feed on the two Dactylopius species regardless of carminic acid concentration. [ABSTRACT FROM AUTHOR]

Divergent host specialization by phytophagous insects is often detected as local adaptation and is thought to have played an important role in their diversification even within an ecological specialist. The phytophagous ladybird beetle Henosepilachna niponica Lewis (Coleoptera: Coccinellidae) predominantly depends on thistles (Cirsium spp., Asteraceae). The distribution of H. niponica occupies multiple areas dominated by different thistle species. This implies the possibility of the occurrence of host‐associated divergent specialization of H. niponica. In this study, we investigated the pattern of host‐use ability of three allopatric H. niponica populations (Aomori, Iwate, and Yamagata) on three thistle species – Cirsium alpicola Nakai, Cirsium nipponicum (Maxim.) Makino, and Cirsium tonense Nakai – under laboratory conditions. The results displayed asymmetric local adaptation by the beetles. The adults and larvae of the Aomori population showed sufficient acceptance and performance on C. nipponicum and C. tonense, the hosts of the Iwate and Yamagata populations, respectively. On the other hand, the Iwate and Yamagata populations fed small amounts of and performed poorly on C. alpicola, the host of the Aomori population. In contrast, the adults from all the populations clearly preferred feeding on C. nipponicum or C. tonense to C. alpicola. We concluded that the small but significant population differentiation and asymmetric local adaptation by beetles to congeneric host plant species could be a sign of the earliest stage of population divergence by divergent natural selection, given that these divergences will act as 'immigrant inviability' and 'habitat isolation' at least asymmetrically when these populations come into contact. [ABSTRACT FROM AUTHOR]

Migration is costly in terms of increased energy expenditure and exposure to risks encountered en route. These factors can lead to a higher mortality among migrants compared with more sedentary life history stages.Insect migrants are incredibly numerous, but as they are less conspicuous than vertebrate migrants and as migration often occurs at high altitude and over a broad front, it can be difficult to study migration‐related mortality. A major source of information on migration‐related mortality comes from cadavers found on the strandline following unsuccessful sea crossings.Here, we analyse strandline mortality following a 100 km crossing of open ocean along the Eastern Mediterranean Flyway from the Middle East mainland to the island of Cyprus by tens of millions of insects.All strandline recordings were of two species of beetles, the seven‐spot ladybird Coccinella septempunctata and the carabid beetle Calosoma olivieri, whereas only nine individuals of C. septempunctata were caught successfully arriving with the rest of the insect assemblage over the ocean.Major strandings were associated with easterly winds, suggesting origins from the Middle East mainland, with the individuals documented as extremely weak and unable to fly or dead.Our results suggest that beetles are weaker migrants than other members of the migratory insect assemblage, with the sea crossing too far for the great majority to fly, leading to high mortality. The impact of this high mortality on the marine ecosystems is discussed. [ABSTRACT FROM AUTHOR]

Biological invasions represent a growing threat to islands and their biodiversity across the world. The isolated sub‐Antarctic island of South Georgia in the South Atlantic Ocean is a highly protected area that relies on effective biosecurity including prevention, surveillance and eradication to limit the risk of biological invasions. Based on an opportunistic field discovery, we provide the first report of an introduced ladybird beetle on South Georgia. All specimens discovered belong to the Eurasian species Coccinella undecimpunctata Linnaeus (1758) (Coleoptera: Coccinellidae). Tens of individuals of both sexes were discovered at a single location, indicating that the species may already be established on South Georgia. Transport connectivity with this site suggests that the species most likely arrived recently from the Falkland Islands as a stowaway on a ship. We discuss the implications of our discovery for the continued development of South Atlantic biosecurity. [ABSTRACT FROM AUTHOR]

Farmers looking to maximize ecosystem services often use diversification practices on their fields to increase abundance and diversity of insect natural enemies. These practices affect functional traits of natural enemies such as body size that can play an important role in their effectiveness as biological control agents. However, landscape features out of the control of farmers might also affect functional traits of natural enemies and their herbivores, including land use surrounding farms. There have been few studies elucidating how landscape complexity and local diversity interact to affect functional traits, and ultimately ecosystem services such as predation on herbivore pests. We examined combined effects of landscape complexity and a local management practice (push‐pull) on lady beetle size, and its consequences for egg predation of lepidopteran pests in Kenyan smallholder maize farms. Cheilomenes sulphurea (Olivier) (Coleoptera: Coccinellidae), a potential predator of the invasive fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), was collected in push‐pull and control fields along a landscape gradient. We measured beetle size and conducted feeding assays with fall armyworm eggs. We found that female beetles had larger bodies in landscapes with greater complexity. Predation rates not only increased as a response to beetle size but also in response to landscape complexity, suggesting it is not just size that determines predation. Surprisingly, we did not find any effect of the local management practice or its interaction on functional traits or predation rates. Our study suggests that landscape complexity could benefit pest control through two mechanisms: (1) increase in predator body size, leading to higher predation rates; and (2) changes in predator behavior as a function of landscape characteristics – increasing egg predation. Further studies on these mechanisms would allow deeper understanding of landscape simplification's effect on ecosystem services, as mediated by morphological and behavioral traits, and help us harness these traits to increase biological control. [ABSTRACT FROM AUTHOR]

The lady beetles Tenuisvalvae notata (Mulsant) and Cryptolaemus montrouzieri Mulsant (both Coleoptera: Coccinellidae), are used in biological control of mealybugs in many countries, including Brazil. As individuals of these species walk on plant surfaces, they leave chemical footprints that can affect their interactions with conspecifics, as well as other coccinellid species in the same environment. Therefore, this study aimed to evaluate the effects of T. notata and C. montrouzieri footprints on both their own and each other's foraging behavior and predatory potential. Arena bioassays were conducted to evaluate the effect of the footprints on conspecifics and heterospecifics. In addition, the chemical profiles of these footprints were analyzed by gas chromatography, flame ionization detection, and mass spectrometry (GC‐FID and GC–MS). For this, extracts of footprints were obtained from a glass Petri dish where 20 adults (males or females) were allowed to walk for 24 h. Behavioral bioassays showed that both species can recognize each other's footprints. Tenuisvalvae notata females avoided areas treated with footprints of heterospecific females, whereas C. montrouzieri females were arrested on areas with footprints of T. notata females. Tenuisvalvae notata adults did not change their predation rate when exposed to the footprints of heterospecifics, but second instars had a higher predation rate on areas treated with heterospecific footprints. Second instar C. montrouzieri also had an increase in predation when exposed to footprints of heterospecifics, and females captured significantly more prey when exposed to footprints of conspecifics, whereas males' predation rate decreased when exposed to footprints of both conspecifics and heterospecifics. The chemical analyses showed that the hexane extracts of footprints were composed mainly of linear hydrocarbons, saturated and non‐saturated, from C20 to C33. The composition (qualitative and quantitative) of footprint extracts is species‐ and sex‐specific. This is the first report on the effects of footprints on the behavior of these species. [ABSTRACT FROM AUTHOR]

Our knowledge on how the local distribution pattern of ordinary and novel hosts promotes or hinders the progress of adaptation to the novel hosts by phytophagous insects is limited. The herbivorous ladybird beetle Henosepilachna vigintioctopunctata (Coleoptera: Coccinellidae) depends mainly on solanaceous plants as hosts; the major wild host of this beetle species in Java, Indonesia, is Solanum torvum. However, in several regions of Southeast Asia, including Java, H. vigintioctopunctata also occurs on the introduced fabaceous weed, Centrosema molle. Circumstantial evidence indicates that the use of C. molle by beetles became frequent in the very early 2000s in East Java. In the present study, based on laboratory and field data obtained from 2003 to 2005, we evaluated the degree of adaptation to C. molle by H. vigintioctopunctata populations from East Java and documented the geographic pattern of host‐plant distribution in East Java. Laboratory experiments revealed that the beetles from East Java possessed the highest degree of adaptation to C. molle among the beetle populations thus far investigated, suggesting that the adaptation to C. molle by beetles proceeded quite rapidly in East Java in the early 2000s. Meanwhile, field surveys showed that the habitats in East Java consisted of mosaics with sites where only C. molle was distributed and sites where C. molle and solanaceous plants co‐occurred. We discussed the role of such geographical structure of habitats in promoting the rapid adaptation of H. vigintioctopunctata to C. molle in East Java. [ABSTRACT FROM AUTHOR]

Biological invasions are usually examined in the context of their impacts on native species. However, few studies have examined the dynamics between invaders when multiple exotic species successfully coexist in a novel environment. Yet, long‐term coexistence of now established exotic species has been observed in North American lady beetle communities. Exotic lady beetles Harmonia axyridis and Coccinella septempunctata were introduced for biological control in agricultural systems and have since become dominant species within these communities. In this study, we investigated coexistence via spatial and temporal niche partitioning among H. axyridis and C. septempunctata using a 31‐year data set from southwestern Michigan, USA. We found evidence of long‐term coexistence through a combination of small‐scale environmental, habitat, and seasonal mechanisms. Across years, H. axyridis and C. septempunctata experienced patterns of cyclical dominance likely related to yearly variation in temperature and precipitation. Within years, populations of C. septempunctata peaked early in the growing season at 550 degree days, while H. axyridis populations grew in the season until 1250 degree days and continued to have high activity after this point. C. septempunctata was generally most abundant in herbaceous crops, whereas H. axyridis did not display strong habitat preferences. These findings suggest that within this region H. axyridis has broader habitat and abiotic environmental preferences, whereas C. septempunctata thrives under more specific ecological conditions. These ecological differences have contributed to the continued coexistence of these two invaders. Understanding the mechanisms that allow for the coexistence of dominant exotic species contributes to native biodiversity conservation management of invaded ecosystems. [ABSTRACT FROM AUTHOR]

Ladybirds (Coleoptera: Coccinellidae) use toxic compounds such as alkaloids in their hemolymph to defend against predators and pathogens. Direct measurement of their toxicity to predators is unavailable as predators show various avoidance reactions without eating the beetles. Because inhibition by harmonine – the alkaloid of the alien invasive ladybird Harmonia axyridis (Pallas) – was observed in many organisms, its toxicity can also be tested on various non‐target organisms. This is the first study examining ladybird alkaloid toxicity to plants. We used a quick, inexpensive, and easy‐to‐perform method to quantify the phytotoxicity of 13 strains of H. axyridis, representing natural colour forms and spontaneous laboratory mutations. We used the seed germination rate and root elongation of seedlings of Sinapis alba L. (Brassicaceae). Following a logistic curve, root length decreased with increasing concentration of the extract from adult beetles. The effect of extracts from the cowpea weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae) (negative control) did not differ from the control (water). Extract from the lesser mealworm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) (positive control) decreased the root length to about half of that of the negative control. Extract from young ladybirds (1 week old) decreased the root length to about one‐third of the control and the extract from 3‐month‐old ladybirds to one‐10th. Differences in toxicity among all 13 strains were minor and not consistent for the two age cohorts. [ABSTRACT FROM AUTHOR]

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short‐term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non‐native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid‐term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management‐intensity gradient. Long‐term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations. Article impact statement: In light of major ecological threats, mitigating actions at different timescales are crucial for ladybird conservation and recovery. [ABSTRACT FROM AUTHOR]

Prey species gain protection by imitating signals of unpalatable models in defensive mimicry. Mimics have been traditionally classified as Batesian (palatable mimic resembling an unpalatable model) or Müllerian (unpalatable mimic resembling a similarly unpalatable model). However, recent studies suggest that rather than discrete categories, the phenomenon of mimicry can be better understood as a continuum. The level of unpalatability of defended prey is a key factor in determining the type of mimetic relationship. Herein, we used insects (ladybugs and true bugs) from a putative European "red–black" mimetic complex as experimental models of defended species and crickets as a control prey. We offered the prey to two species of sympatric invertebrate predators (praying mantis and spider) and video recorded the interactions. We tested three alternative hypotheses, namely (i) the three red–black species tested are similarly defended against both predators; (ii) some red–black species are better defended than others against both predator species, and (iii) the effectiveness of the red–black species defenses is predator dependent. Both predators attacked all prey types with a similar frequency. But while all three red–black species similarly elicited aversive behaviors in spiders, the mantises' aversive reactions varied depending on the prey species. Our results provide support to the third hypothesis, suggesting that the same prey species can fall into different parts of the spectrum of palatability–unpalatability depending on the type of predator. [ABSTRACT FROM AUTHOR]

As a biocontrol agent of aphids and coccids, the harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), was introduced from its native Asian range into North America. There, it has spread quickly and widely, potentially contributing to the decline of endemic ladybirds. This study examined microbial communities residing in H. axyridis in its native and introduced or invaded regions. We collected ladybirds at 11 localities across mainland China (native range) and at seven localities across the USA (invaded range) and applied next‐generation amplicon sequencing to examine microbial communities. We found that the diversity of the microbial community of H. axyridis in the invaded range declined compared to the native range. The microbial community differed markedly in composition between native and invaded ranges. Among all identified 22047 amplicon sequence variants, only 4.2% were shared by the two ranges, whereas 4967 were unique to the invaded and 16159 to the native range. Our findings suggest that the composition of the microbial community of H. axyridis is largely restructured in the invaded North American region compared to the native Asian region. [ABSTRACT FROM AUTHOR]

Facultative endosymbionts can induce benefits and costs to their aphid hosts. In the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), infection with the γ‐proteobacterium Hamiltonella defensa Moran et al. can confer resistance against parasitoids, but may also reduce the frequency of aggressive and escape behaviours exhibited in response to predators. In potato aphids, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae), H. defensa does not appear to influence susceptibility to parasitism, but its impact on anti‐predator behaviours remains unexplored. Here we investigated defensive behaviours in two pea aphid lines (differing in H. defensa‐infection status) and four potato aphid lines (that additionally differed in genotype‐associated parasitism susceptibility) when faced with foraging ladybirds – Adalia bipunctata (L.) (Coleoptera: Coccinellidae) – and lacewings – Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). In response to ladybirds, symbiont‐infected pea aphids exhibited proportionately fewer evasive defences (dropping and walking away) than non‐infected (cured) pea aphids, but more frequent aggressive kicking. Ladybirds provoked more evasive, aggressive, and total defensive behaviours than lacewings. For potato aphids, symbiont status, predator type, and aphid genotype (i.e., assumed parasitism susceptibility) all influenced behavioural repertoires. Overall, infected lines showed greater differentiation in behaviours in response to the two predators than the uninfected lines. The presence of the symbiont H. defensa may be a key determinant of aphid anti‐predator behaviours, but the fitness consequences of this are unresolved. In our study, neither symbiont infection status nor aphid genotype affected the number of aphids consumed by predators. [ABSTRACT FROM AUTHOR]

Investigating the well‐established relationships between insects and novel host plants will shed light on numerous aspects of evolution and ecology of phytophagous insects. However, in these systems, it is not always clear which plants were originally used as insect hosts, and how the focal insects adapted to the original host(s), before establishing the novel insect–host relationships. Henosepilachna vigintioctomaculata (Motschulsky) (Coleoptera: Coccinellidae) is a well‐known pest of the potato Solanum tuberosum (Solanaceae), however its original host in Honshu, the main island of Japan, before the potato introduction is uncertain. A wild solanaceous weed, So. megacarpum, is the most likely candidate for the original host, although the use of this plant by H. vigintioctomaculata has never been recorded in Honshu. This study reports the occurrence of a H. vigintioctomaculata population depending almost solely on So. megacarpum at Yamagata, northern Honshu. Additionally, the host‐use ability of this population was compared to that of a pest population under laboratory conditions. Based on the results obtained, it is discussed how the properties of beetles on So. megacarpum facilitated the use of the potato, assuming that So. megacarpum was the original host of H. vigintioctomaculata in Honshu. [ABSTRACT FROM AUTHOR]

Cochineal is the common name for cactus‐feeding scale insects in the Dactylopiidae. These ruby‐red insects include the domesticated dye insect Dactylopius coccus. Dactylopius coccus and congeners have been introduced around the world, some accidentally, to become pests of prickly pear cactus species (Opuntia), and some intentionally, for dye production or biological control of pest Opuntia. In the northern Sonoran Desert (Tucson, AZ, USA), we studied the enemy complex of D. opuntiae and D. confusus on Opuntia and characterized two cryptic enemies, a coccinellid beetle predator and a parasitoid wasp. (1) Hyperaspis sp. The coccinellid predator Hyperaspis trifurcata shares a niche with a similar, typically all‐black beetle. Morphological data, crossing tests, and phylogenetic results showed the black beetle to be a distinct, undescribed species in the genus Hyperaspis, with a rare spotted phenotype that is similar in appearance to H. trifurcata. Crossing tests among black and spotted forms showed the spotted morph is inherited as a single‐locus dominant allele. (2) Formicencyrtus thoreauini. Rearing of this ant‐like parasitoid wasp (Encyrtidae) in pure culture of D. opuntiae showed it to be a semi‐gregarious primary parasitoid of cochineal. To our knowledge, this is the first confirmed instance of a cochineal parasitoid. Observations of development show early instar larvae keep their posterior end within the egg chorion, attached to an aeroscopic plate with a connection to the cochineal body wall. Late instar larvae are eventually surrounded by a membrane, likely of larval origin. Wasps then pupate in a dry air‐filled chamber within the desiccated scale remains before chewing out as an adult. Both Hyperaspis sp. and F. thoreauini may have restricted distributions. Hyperaspis sp. does not appear to be a member of the cochineal community in Mexico or Texas, and scant records suggest F. thoreauini may also be restricted to the Southwestern USA. [ABSTRACT FROM AUTHOR]

Keywords: biological control; coccinellidae; Harmonia axyridis; IGP; invasive species; ladybirds EN biological control coccinellidae Harmonia axyridis IGP invasive species ladybirds 249 252 4 05/10/22 20220601 NES 220601 INTRODUCTION The spatial range of many species is shifting dramatically over time in response to environmental change (MacLean & Beissinger, 2017). Indeed, the paper by Brown et al. (2011) makes very limited reference to biological control, whilst Soares et al. (2008) do not once claim that I H. axyridis i , or other non-native ladybird species, lower the biological control potential of the ladybird guild. 5 Brown, P.M.J. & Roy, H.E. (2018) Native ladybird decline caused by the invasive harlequin ladybird Harmonia axyridis: evidence from a long-term field study. (2016) The influence of exotic lady beetle (Coleoptera: Coccinellidae) establishment on the species composition of the native lady beetle community in Missouri. [Extracted from the article]

Surface features of plants can influence the searching efficiency and survival of predatory insects. Surfaces act as barriers preventing attachment of both phytophages and also their insect predators. In this regard, we focused on the oviposition site selection and the attachment ability of all life stages (eggs, larvae, imagines) of two common ladybird species, Propylea quatuordecimpunctata and Harmonia axyridis (Coleoptera: Coccinellidae), on artificial and natural substrates with different surface features and properties (roughness, wettability). Both species preferred a hydrophilic surface as the oviposition site and this can be correlated with the better performance of both larvae and adults on these substrates compared with hydrophobic ones. The egg glue of both ladybird species can wet hydrophobic surfaces such as those of many plant leaves and also with prominent 3D wax coverage. The surface roughness has an important role in the oviposition site selection in P. quatuordecimpunctata, but not in H. axyridis. The oviposition preference for smooth surfaces in P. quatuordecimpunctata could be due to better performance of larvae on smooth substrates compared with rough ones. The egg glue of both species can adapt to artificial and natural surfaces characterized by different asperity sizes faithfully replicating their shape, except for very high asperity sizes or big trichomes. The results of the present research can shed light on the mechanical ecology of the evolutionary successful Coccinellidae and may aid in the development of suitable substrates for coccinellid egg‐laying, in order to improve the mass rearing technique of species used in biological control. [ABSTRACT FROM AUTHOR]

Local adaptation to different host plants is important in the diversification of phytophagous insects. Thus far, much evidence of the local adaptation of insects with respect to host use at the physiological level has been gathered from systems involving less mobile insects and/or divergent hosts such as plants belonging to different families or genera. On the other hand, the prevalence of such local adaptation of insects with moderate or high dispersal ability to the intraspecific variation of herbaceous hosts is largely unknown. In the present study, we examined the occurrence and degree of local adaptation of the herbivorous ladybird beetle Henosepilachna pustulosa (Kôno) (Coleoptera: Coccinellidae) to its primary host, the thistle Cirsium boreale Kitam. (Asteraceae), through reciprocal laboratory experiments using beetles and thistles from three locations with a range of approximately 200 km. Concerning the larval developmental ability, obvious patterns of local adaptation to the thistles from respective natal locations were detected, at least in some combinations of beetle populations. Similar tendencies were detected concerning adult feeding acceptance, although the statistical support was somewhat obscure. Overall, our results indicate that the degree of local adaptation of insect species with moderate dispersal ability to conspecific herbaceous hosts is occasionally as strong as that involving less mobile insects and/or heterospecific hosts, indicating the potential of such cryptic local adaptation to promote ecological/genetic differentiation of phytophagous insect populations. [ABSTRACT FROM AUTHOR]

Cereal aphids are known as serious pests that cause considerable yield losses of wheat production. In this study, cereal aphids and their common natural enemies inhabiting the commercial wheat crop were investigated between February and April 2013 as a preliminary study in the Hail region, northern Saudi Arabia. Results showed that wheat crops were infested by four aphid species including the Russian wheat aphid Diuraphis noxia Kurdjumov, the English grain aphid Sitobion avenae Fabricius, the bird cherry‐oat aphid Rhopalosiphum padi L. and the greenbug aphid Schizaphis graminum Rondani (Homoptera: Aphididae). The Russian wheat aphid D. noxia, however, was the most abundant species compared to other aphid species, totaling 343 individuals which represented 39.80% of all cereal aphids. The results showed a diverse community of specialist natural enemies that were associated aphids including parasitoid wasps as a complex and one Braconid species Aphidius matricariae Haliday (Hymenoptera: Braconidae), three coccinellid species (Adonia variegate Goeze, Coccinella quinquepunctata L. and Coccinella septimpunctata L.) (Coleoptera: Coccinellidae), one species of lacewing Chrysopa sp. (adults & larvae) (Neuroptera: Chrysopidae) and one species of hoverfly Eristalinus aeneus Scop. (adults and larvae) (Diptera: Syrphidae). This study, also, recorded a high abundance of polyphagous predators that included two species of ground beetles involving the black beetle Calosoma olivieri Dejean and Calosoma imbricatum Klug (Coleoptera: Carabidae), and spiders (Araneae) as generalist natural enemies of cereal aphids. In this article, population dynamics of captured cereal aphids and their common natural enemies, and their correlations will be described and discussed. [ABSTRACT FROM AUTHOR]

Incidence of parasitism is often underestimated because 'ghost' parasitoids (dead unemerged parasitoids or those that have emerged leaving the host carcasses) are difficult to detect and identify. This study demonstrates that the use of melting curve analysis (MCA) of host carcasses can detect and identify DNA of ghost parasitoids even a month after host death.The coccinellid hosts Cycloneda sanguinea, Eriopis connexa, Harmonia axyridis and Hippodamia convergens were sampled from cole crops in 2017 and 2018 in the Midwest of Brazil, and reared and observed daily for parasitoid emergence. Dead coccinellids were held for 30 days after death before storage and only host carcasses with parasitoid emergence observed were analysed. Species‐specific primers were designed for the identification of the parasitoid species that emerged during host rearing: Dinocampus coccinellae, Homalotylus mirabilis, Ho. terminalis, Strongygaster triangulifera and Phalacrotophora sp. The melting temperatures (Tm) of their amplicons were used as positive controls in MCA post‐amplification in qPCR.Detection of parasitoid DNA in host carcasses was possible for D. coccinellae, Ho. mirabilis and Phalacrotophora sp. with a limit of detection (LOD) for all the parasitoids <1 pg of DNA, except for Phalacroptopthora sp. (LOD = 1.9 ng). Parasitoids were detected in 31 out of 70 host carcasses (44.3%) with detection ranging from 0% to 71%, depending on the parasitoid species.Synthesis and applications. This work demonstrates that MCA could be used to detect and rapidly identify the DNA of some parasitoid species (e.g. Ho. mirabilis, D. coccinellae and Phalacrotophora sp.) in host carcasses up to a month after parasitoid emergence with high sensitivity and specificity. MCA can be used on any field‐collected host and, for some parasitoid species, it should lead to more accurate estimates of the incidence of parasitism. Our approach can be easily adapted and applied to study other parasitoid–host interactions. [ABSTRACT FROM AUTHOR]

Predaceous coccinellids can feed on non‐prey food, but the ecological value of this feeding to maintain a coccinellid population is not well understood. Prey density can vary greatly in the field, whereas non‐prey food sources such as pollen and nectar are more predictable. In the present study, Adalia bipunctata L. (Coleoptera: Coccinellidae) larval performance on pure and mixed diets of a high‐quality non‐prey food with varying amounts of prey was investigated. Rosy apple aphid, Dysaphis plantaginea Passerini (Hemiptera: Aphididae), served as prey in the experiment and was given to A. bipunctata larvae either ad libitum as a surplus diet or as a limited diet, the amount of which was selected so that it would limit larval development, according to a pilot study. Flowers of buckwheat, Fagopyrum esculentum L. (Polygonaceae), a high‐value floral diet, served as the non‐prey food. Newly hatched A. bipunctata larvae were reared on each of five diets: (1) flowers only, (2) limited prey only, (3) limited prey plus flowers, (4) surplus prey only, (5) surplus prey plus flowers. Larval survival, developmental time, and adult dry weight were measured. The addition of floral diet had a significant positive impact on A. bipunctata larval survival and development when prey diet was limited, survival ratio was 6× higher and developmental time was 25% shorter. In conclusion, A. bipunctata immature development can benefit from a floral diet supplemented to a prey diet, which indicates that the use of flowers in cropping systems can help to enhance biocontrol services by A. bipunctata. [ABSTRACT FROM AUTHOR]

Three artificial diets were developed and tested for their suitability for immature development and survival of the ladybird Propylea japonica (Thunberg) (Coleoptera: Coccinellidae). The artificial diet based on the oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae), resulted in 66.5% survival and was a potential food for mass rearing of P. japonica. The effect of this alternative diet was assessed independently for larval development and adult reproduction by adding various numbers of frozen aphids, and finally an artificial rearing scheme was established that could save about 80% of natural food (aphids). The results showed that the survival rate and fecundity of P. japonica reared on the best artificial diet or aphids alone were similar. A rearing scheme using mainly M. separata‐based artificial diet and a small number of frozen aphids for the mass production of P. japonica became possible. [ABSTRACT FROM AUTHOR]

Community scientists have illustrated rapid declines of several aphidophagous lady beetle (Coccinellidae) species. These declines coincide with the establishment of alien coccinellids. We established the Buckeye Lady Beetle Blitz program to measure the seasonal occupancy of coccinellids within gardens across a wide range of landscape contexts. Following the Habitat Compression Hypothesis, we predicted that gardens within agricultural landscapes would be alien‐dominated, whereas captures of natives would be higher within landscapes encompassing a high concentration of natural habitat.Within the state of Ohio, USA, community scientists collected lady beetles for a 7‐day period across 4 years in June and August using yellow sticky card traps. All identifications were verified by professional scientists and beetles were classified by three traits: status (alien or native), mean body length, and primary diet. We compared the relative abundance and diversity of coccinellids seasonally and determined if the distribution of beetles by size, status, and diet was related to landscape features.Alien species dominated the aphidophagous fauna. Native aphidophagous coccinellid abundance was positively correlated with forest habitat while alien species were more common when gardens were embedded within agricultural landscapes. Urbanization was negatively associated with both aphidophagous alien and native coccinellids.Synthesis and Applications: Our census of native coccinellid species within residential gardens—a widespread and understudied habitat—was enabled by volunteers. These data will serve as an important baseline to track future changes within coccinellid communities within this region. We found that native coccinellid species richness and native aphidophagous coccinellid abundance in gardens were positively associated with forest habitat at a landscape scale of 2 km. However, our understanding of when and why (overwintering, summer foraging, or both) forest habitats are important remains unclear. Our findings highlight the need to understand how declining aphidophagous native species utilize forest habitats as a conservation priority. [ABSTRACT FROM AUTHOR]

Large geographic range, wide habitat specificity and broad range of prey (including a number of pests of protected crops) suggest that a predatory ladybird Cheilomenes propinqua can be considered as potential agent for biological control in greenhouses. We investigated the influence of day length (10, 12 and 14 hr), temperature (20 and 24°C) and diet (the green peach aphid Myzus persicae and eggs of the grain moth Sitotroga cerealella) on the rate of maturation, fecundity and induction of reproductive diapause in C. propinqua females of a laboratory population originated from Alexandria, Egypt. The proportion of diapausing females (i.e. those with poorly developed ovaries and well‐developed fat body) varied from 5% to 70% being higher at short day, low temperature and feeding on the grain moth eggs. This diapause, however, was not very stable: more than 20% of females kept under diapause‐inducing conditions started to lay eggs during 110 days, although their pre‐oviposition period was about 5 times longer than that of females which matured at the same temperature but at the long day and on the natural diet. Although not very stable, reproductive diapause significantly increased survival of starving females. Such a short‐term reproductive diapause can be considered as an adaptation to mild and short‐term subtropical winter. The results of our study suggest that C. propinqua mass rearing will be more intensive at the combination of high temperature, natural food (aphids) and long day (14 hr), whereas individuals intended for long‐term storage should be reared under moderate temperature (20°C) and short‐day (10 hr) conditions and should be fed on factitious food (the grain moth eggs). [ABSTRACT FROM AUTHOR]

Since the late 19th century, exotic ladybirds (Coleoptera: Coccinellidae) have been used extensively for suppressing herbivorous insects of economic importance. In recent decades, the introduction of non‐native biological control (BC) agents has been greatly limited due to the awareness of the potential non‐target effects of introductions. Nonetheless, recent episodes of biological invasions of economically important pests have raised the need to carefully consider whether the expected benefits of pest control go beyond the possible environmental risks of introduction. To better understand the factors that contributed to successful BC programs, here we review the literature behind classical and augmentative BC using exotic ladybirds. Additionally, by means of case studies, we discuss the BC efficacy of selected exotic species, e.g., Coccinella septempunctata L., Harmonia axyridis (Pallas), and Hippodamia variegata (Goeze), and their position within the communities of predators in the introduced areas of USA, Canada, and Chile. In Europe, much of the research on exotic ladybirds has been conducted on the undesired impact of H. axyridis. Therefore, we summarize the risk assessment data for this species and review the field research investigating the ecological impact on European aphidophagous predators. According to the BIOCAT database of classical BC programs, 212 ladybird species belonging to 68 genera have been released in about 130 years of BC activity, with 14.6% of introductions having resulted in partial, substantial, or complete control of the target pest. However, because post‐release evaluation of establishment and BC success has not always been conducted, this rate could underestimate the successful cases. Among other factors, ladybird establishment and pest suppression mostly depend on (1) intrinsic factors, i.e., high voracity, synchronized predator‐prey life cycle, and high dispersal ability, and (2) extrinsic factors, i.e., adaptability to the new environment and landscape composition. This review contributes to improved understanding of ladybirds as exotic BC agents. [ABSTRACT FROM AUTHOR]

Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is a sub‐cosmopolitan species. Native to Asia, it has been released during the 20th century for classical and augmentative biological control of several herbivorous insects, mostly aphids and coccids. Despite its recognized positive impact on biological control, H. axyridis is now considered among the most dangerous invasive species in Europe and in most places where it has established. This is mostly due to its ability to reduce the populations of native predatory species of the same trophic guild. When exploring a new area, H. axyridis adults use semiochemical cues to acquire information about the habitat. Presumably, these cues are perceived by the sensilla located on the antennae. Surprisingly, in spite of the huge literature existing on H. axyridis, the antennal sensory organs have been poorly characterized. Here, we used scanning and transmission electron microscopy (SEM, TEM) techniques to study H. axyridis antennae, with focus on the various types of sensilla and their distribution in male and female individuals. The presence of various classes of antennal sensilla belonging to the main types described in insects (chemoreceptors, mechanoreceptors, and thermo‐hygroreceptors) was highlighted, as well as the widespread presence of antennal glands. The investigations showed some peculiar characteristics not known in Coccinellidae, such as the concentration of sensory structures at the level of the distal part of the apical antennomere and the discovery of antennal glands associated with it. No sexual dimorphism was revealed, neither for the general structure of the antenna (similar number of antennomeres and presence of modifications), nor for the total length and width of the antenna, the relative size of the antennomeres, the types of antennal sensilla, of their distribution and abundance. The potential relevance of these sensory structures and antennal glands, reported for the first time in Coccinellidae, is discussed in the context of intra‐ and interspecific communication. [ABSTRACT FROM AUTHOR]

Novel predator–prey interactions can contribute to the invasion success of non‐native predators. For example, native prey can fail to recognize and avoid non‐native predators due to a lack of co‐evolutionary history and cue dissimilarity with native predators. This might result in a competitive advantage for non‐native predators. Numerous lady beetle species were globally redistributed as biological control agents against aphids, resulting in novel predator–prey interactions. Here, we investigated the strength of avoidance behavior of the pea aphid (Acyrthosiphon pisum) toward chemical cues of native lady beetles and non‐native Asian Harmonia axyridis and European Coccinella septempunctata and Hippodamia variegata in North America, hypothesizing that cues of non‐native lady beetles induce weaker avoidance behavior than cues of co‐evolved native lady beetles. Additionally, we compared aphid consumption of lady beetles, examining potential predation advantages of non‐native lady beetles. Finally, we compared cue avoidance behavior between North American and European pea aphid populations and aphid consumption of native and non‐native lady beetles in North America and Europe. In North America, pea aphids avoided chemical cues of all ladybeetle species tested, regardless of their origin. In contrast to pea aphids in North America, European pea aphids did not avoid cues of the non‐native H. axyridis. The non‐native H. axyridis and C. septempunctata were among the largest and most voracious lady beetle species tested, on both continents. Consequently, in North America non‐native lady beetle species might have a competitive advantage on shared food resources due to their relatively large body size, compared to several native American lady beetle species. In Europe, however, non‐native H. axyridis might benefit from missing aphid cue avoidance as well as a large body size. The co‐evolutionary time gap between the European and North American invasion of H. axyridis likely explains the intercontinental differences in cue avoidance behavior and might indicate evolution in aphids toward non‐native predators. [ABSTRACT FROM AUTHOR]

While many predatory arthropods consume non‐prey foods from lower trophic levels, little is known about what drives the shift from predator to omnivore. Predatory lady beetles often consume non‐prey foods like plant foliage and pollen. One species, Coccinella septempunctata, eats foliage to redress sterol deficits caused by eating sterol‐deficient prey. Here we explore how omnivory benefits lady beetle fitness.We reared seven species of lady beetles—from five genera distributed across the tribe Coccinellini—on pea aphids in the presence or absence of fava bean foliage; pea aphids have very low sterol content. Foliage supplements lengthened the development times of four species and decreased survival to adulthood of two species; it had no effect on adult mass. We mated beetles in a 2 × 2 factorial design (males with or without foliage paired with females with or without foliage). For each species, we observed a profound paternal effect of foliage supplements on fitness. Females mated to foliage‐supplemented males laid more eggs and more viable eggs compared to females mated to non‐supplemented males. Foliage‐supplemented males produced 2.9–4.6 times more sperm compared to non‐supplemented males for the three species we examined.We analysed the sterol profile of four beetle species reared on pea aphids—with or without foliage—and compared their sterol profile to field‐collected adults. For two laboratory‐reared species, sterols were not detected in adult male beetles, and overall levels were generally low (total ng of sterol/beetle range: 3–33 ng); the exception being Propylea quatuordecimpunctata females (total ng of sterol/beetle range: 50–157 ng). Laboratory‐reared lady beetle sterol content was not significantly affected by the presence of foliage. Field‐collected beetles had higher levels of sterols compared to laboratory‐reared beetles (2,452–145,348 ng per beetle); cholesterol and sitosterol were the dominant sterols in both field‐collected and laboratory‐reared beetles.Our findings indicate that herbivory benefits lady beetle fitness across the Coccinellini, and that this was entirely a paternal effect. Our data provide a rare example of a nutritional constraint impacting fitness in a sex‐specific manner. It also shows, more broadly, how a nutritional constraint can drive predators towards omnivory. [ABSTRACT FROM AUTHOR]

1. Generalist predators are important contributors to reliable conservation biological control. Indirect interactions between prey species that share a common generalist predator can influence both community dynamics and the efficacy of biological control. 2. Laboratory cage experiments investigated the impact of the combined consumptive and non‐consumptive effects of predation by adult Hippodamia convergens as a shared predator on the population growth and relative abundance of Acyrthosiphon pisum and Aphis gossypii as prey species. Predation pressure and prey density were varied. 3. At low predation pressure the indirect interaction between aphid species was asymmetrical with a proportionally greater negative impact of predation on A. gossypii than on A. pisum. At intermediate predation pressure, the indirect interaction became symmetrical. At high predation pressure and higher levels of prey density, it was asymmetrical with greater negative impact on A. pisum, often driven to local extinction while A. gossypii populations persisted. 4. A linear mixed‐effects model including early population growth of both aphid species and predation pressure explained 96% and 92% of the variation in the population growth of A. pisum and A. gossypii, respectively, over an 8‐day period. The overall effect of shared predation on the indirect interaction between the two aphid species is best described as apparent commensalism, where A. pisum benefited from early population growth of A. gossypii, while A. gossypii was unaffected by early population growth of A. pisum. Considering these indirect interactions is important for conservation biological control efforts to be successful. [ABSTRACT FROM AUTHOR]

Natural enemies resistant to insecticides are expected to help control the remaining arthropod pests after insecticide application and, hence, prevent crop damage, pest resurgence, and resistance selection. Field‐evolved resistance to lambda‐cyhalothrin and to other pyrethroids exhibited by the neotropical ladybird beetle Eriopis connexa (Germar) (Coleoptera: Coccinellidae) has been characterized and enhanced under laboratory selection. In this study, we investigated the stability of the resistance and its relationship with detoxification enzyme activity and biological performance, which are important for a biocontrol agent. One subgroup of the resistant population of E. connexa was established without selection pressure (R‐UNSEL) during eight generations, and compared to either a susceptible (SUS) or its parental resistant (R‐SEL) population. The resistance ratio in R‐UNSEL was reduced by 50% compared to R‐SEL between the first and fourth generation without selection pressure, but stayed stable afterwards, from the fifth to the eighth generation. Despite eight generations without selection pressure and reduction in the resistance level, the resistance ratio in R‐UNSEL was still 39× greater than in the SUS population. The reduced resistance in R‐UNSEL correlated to reduction in esterase activity, but the R‐UNSEL maintained greater activity than the SUS group. The absence of selection pressure and reduction in enzyme activity in R‐UNSEL did not mitigate the adaptive costs, with 2.7× lower egg production compared to SUS females. These findings indicate that resistance to lambda‐cyhalothrin in R‐UNSEL has already stabilized in the population. Although the resistance ratio and detoxifying enzymes were reduced in R‐UNSEL, the impact on fecundity was maintained. Furthermore, the absence of crossing with wild SUS individuals will allow the R‐UNSEL offspring to retain the resistance allowing survival to lambda‐cyhalothrin even when used at the highest recommended field rate. [ABSTRACT FROM AUTHOR]

Advances in genomic biology and the increasing availability of genomic resources allow developing hundreds of nuclear protein‐coding (NPC) markers, which can be used in phylogenetic research. However, for low taxonomic levels, it may be more practical to select a handful of suitable molecular loci for phylogenetic inference. Unfortunately, the presence of degenerate primers of NPC markers can be a major impediment, as the amplification success rate is low and they tend to amplify nontargeted regions. In this study, we optimized five NPC fragments widely used in beetle phylogenetics (i.e., two parts of carbamoyl‐phosphate synthetase: CADXM and CADMC, Topoisomerase, Wingless and Pepck) by reducing the degenerate site of primers and the length of target genes slightly. These five NPC fragments and 6 other molecular loci were amplified to test the monophyly of the coccinellid genus Sasajiscymnus Vandenberg. The analysis of our molecular data set clearly supported the genus Sasajiscymnus may be monophyletic but confirmation with an extended sampling is required. A fossil‐calibrated chronogram was generated by BEAST, indicating an origin of the genus at the end of the Cretaceous (77.87 Myr). Furthermore, a phylogenetic informativeness profile was generated to compare the phylogenetic properties of each gene more explicitly. The results showed that COI provides the strongest phylogenetic signal among all the genes, but Pepck, Topoisomerase, CADXM and CADMC are also relatively informative. Our results provide insight into the evolution of the genus Sasajiscymnus, and also enrich the molecular data resources for further study. [ABSTRACT FROM AUTHOR]

1. While there has been considerable focus on prey occurrence as a factor determining the habitat preference of predators, the roles of other factors related to the habitat are less well characterised. 2. In aphidophagous ladybird beetles (Coleoptera: Coccinellidae), a number of species are more restricted in the habitats in which they live than are their prey. A number of such ladybirds appear to show geographic variation in habitat preference. 3. To better understand these phenomena, this study considered geographic variation in habitat preference in one such species, the 5‐spot ladybird Coccinella quinquepunctata. Because of this ladybird's scarcity, a combination of over 20 years' observations, habitat surveys and online data was used to reach the study's conclusions. 4. The data collected indicate that the ladybird is specialised in pioneer habitats close to water, but broadens its range to non‐riverine pioneer habitats in north‐west continental Europe, where it is likely that a damper (micro)climate allows it to do so. Thus, microclimatic factors appear to be important in determining the habitat of this and probably other predators that are not constrained by prey occurrence. 5. Although threatened by river management elsewhere, in north‐western Europe, this species clearly benefits from human activity, which creates many of the disturbed habitats it colonises there. This finding provides further support for the contention that many ladybirds are net beneficiaries of human influence, although they are often characterised as threatened. [ABSTRACT FROM AUTHOR]

Colour and colour patterns seem to be especially important visual warning signals for predators, which might have innate or learned ability to avoid aposematic prey. To test the importance of larval colour pattern of the aposematic ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an invasive alien species in Europe, we presented the plasticine models of aposematic larvae to wild and naïve birds. We studied the attacks on aposematic larvae of various patterns and colours in nature and in an outdoor aviary. The larvae were cryptic (green), aposematic (resembling those of the H. axyridis larvae), and semi‐aposematic (i.e., black but missing the typical orange patches of H. axyridis larvae). We detected attacks on 71 larvae out of 450 (i.e., 2.6% daily predation). Twenty‐nine attacks were made by birds, 37 by arthropods, and five by gastropods. Wild birds attacked green and black larvae significantly more often than aposematic larvae. Colour did not have an effect on attacks by arthropods. The experiment with naïve birds was conducted in an outdoor aviary, where naïve great tits, Parus major L., were offered the same artificial larvae as in the first experiment. In total, 57 of 90 exposed larvae were attacked by birds (i.e., 28% daily predation), and green larvae were attacked significantly more than the aposematic larvae (but not more than black larvae). Our results imply that aposematic larvae of H. axyridis are more than 12× less likely to be predated by birds than green larvae in nature. The aposematic pattern represented a more effective signal than the semi‐aposematic signal. The ability to reject aposematic prey seemed to be innate in our birds. [ABSTRACT FROM AUTHOR]

Augmentative biological control by predaceous ladybird beetles can be improved by using flightless morphs, which have longer residence times on the host plants. The two‐spot ladybird beetle, Adalia bipunctata (L.) (Coleoptera: Coccinellidae), is used for the biological control of aphids in greenhouses and on urban trees. Flightlessness due to truncated wings occurs at very low frequency in some natural populations of A. bipunctata. Pure‐breeding strains of this 'wingless' genotype of A. bipunctata can easily be obtained in the laboratory. Such strains have not been commercialized yet due to concerns about their reduced fitness compared to wild‐type strains, which renders mass production more expensive. Wingless strains exhibit, however, wide intra‐population phenotypic variation in the extent of wing truncation which is related to fitness traits. We here use classical quantitative genetic techniques to study the heritability and genetic architecture of variation in wing truncation in a wingless strain of A. bipunctata. Split‐families reared at one of two temperatures revealed strong family‐by‐temperature interaction: heritability was estimated as 0.64 ± 0.09 at 19 °C and 0.29 ± 0.06 at 29 °C. Artificial selection in opposite directions at 21 °C demonstrated that the degree of wing truncation can be altered within a few generations resulting in wingless phenotypes without any wing tissue (realized h2 = 0.72), as well as those with minimal truncations (realized h2 = 0.61) in two replicates. The latter lines produced more than twice as many individuals. This indicates that selective breeding of wing truncation may be exploited to improve mass rearing of flightless strains of A. bipunctata for commercial biological control. Our work illustrates that cryptic variation can also be a source for the selective breeding of natural enemies. [ABSTRACT FROM AUTHOR]

Transgenic Bacillus thuringiensis Berliner (Bt) crops receive particular attention because they carry genes encoding insecticidal proteins that might negatively affect non‐target arthropods. Here, laboratory experiments were conducted to evaluate the impact of Cry1Ab‐expressing transgenic maize [5422Bt1 (event Bt11) and 5422CBCL (MON810)] on the biological parameters of two non‐target arthropods, the aphid Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae) and its predator the ladybeetle Propylea japonica (Thunberg) (Coleoptera: Coccinellidae). In a long‐term assay (three generations), no significant differences were found between R. maidis fed Bt maize and those fed a near‐isogenic line (5422) when individual parameters were compared, including nymph development time, adult longevity, aphid spawning period, and fecundity. No negative effects were detected throughout the life cycle of P. japonica in aphids' feeding amount, development (nymphs, pupae, adults, and progeny eggs), fecundity, or egg hatching when they preyed on Bt maize‐fed aphids compared with non‐Bt maize treatments. A tritrophic assay revealed that Cry1Ab was highly diluted through the food chain (Bt maize leaves, R. maidis, and P. japonica), as detected by an enzyme‐linked immunosorbent assay (ELISA). In conclusion, although Cry1Ab concentrations in maize leaves increased as the plants developed, Cry1Ab levels were significantly reduced in the aphid R. maidis, and no traces of Cry1Ab were detected in P. japonica preying on Bt maize‐fed aphids. The two hybrids of Bt maize expressing Cry1Ab had no negative effects on the measured biological parameters of the aphid R. maidis or its predator, the ladybeetle P. japonica. [ABSTRACT FROM AUTHOR]

Brevicoryne brassicae (L), Lipaphis erysimi (Kalt) and Myzus persicae (Sultzer) (Homoptera: Aphididae) form the aphid complex that causes great losses in Brassicaceae in tropical and subtropical regions. Knowledge of their population dynamics is important for the development of integrated pest management programmes. This study aimed to investigate the effects of cabbage phenology, climatic factors and natural enemies populations on the dynamics of these organisms, and the factors regulating their predators' occurrence. The densities of aphids and their natural enemies and the climate were monitored for two years in 16 cabbage crops. The highest densities of the aphids occurred during periods of relative humidity (RH) drop, a condition that affects them positively. Regarding the predators, the factors affecting their abundance varied but RH was positively related to most of them. This study provides relevant insights into the factors that regulate the aphids in cabbage and for the decision‐making process of control of these severe pests. [ABSTRACT FROM AUTHOR]

Climate change is expected to increase the frequency of periods of extreme weather events, including heat waves that are harmful to arthropod natural enemies. We studied the thermotolerance of the ladybeetle Serangium japonicum Chapin (Coleoptera: Coccinellidae), an important native predator of the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in China. Serangium japonicum eggs, first‐ and fourth‐instar larvae, pupae, and adults were subjected to a range of high temperatures (36, 39, 42, 43.5, and 45 °C) at intervals between 15 and 720 min. Survival was compromised and declined sharply for all life stages at temperatures of 42 °C and higher. First instars were the least heat tolerant, and eggs were typically the most resistant. Egg predation by S. japonicum did not differ whether the adult beetles were subjected to either heat shock or starvation first. Heat shock treatments at 36 °C did not impede adult egg consumption, treatments at 39 °C crippled ladybeetle's egg consumption for 8 h following treatment but recovered predatory capacity within 24 h after treatment. However, treatments at 42 °C greatly impaired ladybeetle's predatory capacity. After experiencing heat shock at 39 and 42 °C, adults significantly increased the amount of time they spent resting, which is the probable cause of predation decline after heat exposure. These results demonstrate that short periods of extreme heat exposures have a detrimental impact on S. japonicum survival and predation, but the effect was dependent on duration and life stage. Overall, these findings can help predict population dynamics and success of biological control of whitefly by S. japonicum in a warming world. [ABSTRACT FROM AUTHOR]

Harmonia axyridis (Pallas) and Propylea japonica (Thunberg) (both Coleoptera: Coccinellidae) are two common aphidophagous predators that overlap in their natural niche; therefore, interactions between these two predator species could affect their overall prey consumption. The consequences of intraguild interactions on the foraging efficiency of the two coccinellid species were investigated by evaluating the functional responses of single beetles and intra‐ and interspecific combinations to densities of the spirea aphid, Aphis citricola van der Goot (Hemiptera: Aphididae), on apple seedlings, during 2 and 12 h under laboratory conditions. A type II functional response was observed in all the bioassays. Solitary H. axyridis consumed significantly more aphids than single P. japonica in both exposure periods. However, at intermediate prey densities the prey consumption of P. japonica was slightly greater than that of H. axyridis. The 95% confidence intervals of the functional response curves of conspecific and heterospecific pairs overlapped at 2 h. In contrast, conspecific pairs of H. axyridis showed a higher functional response curve at 12 h compared to a combination of H. axyridis and P. japonica. Prey's predation risk reduction was only detected for paired H. axyridis and mixed predators compared to their estimated functional responses at the 2‐h foraging period. By comparing functional responses between intraguild predatory lady beetle combinations, we could further predict the potential ecosystem service provided by these natural enemies. Comparison of functional responses between various combinations of predators is a valuable approach to predict and assess multiple predator impact on their shared prey populations. Functional responses of single and intra‐ and interspecific combinations of Harmonia axyridis and Propylea japonica (Coleoptera: Coccinellidae) to densities of Aphis citricola (Hemiptera: Aphididae) on apple seedlings were evaluated at two exposure times under laboratory conditions. Our results indicated that interactions between the predatory beetles can alter their functional responses, and thus their overall prey consumption. [ABSTRACT FROM AUTHOR]

BACKGROUND: Knowledge of the nutritional ecology of predatory coccinellids is important for the selection of efficient biocontrol agents. We examined five species common in pistachio orchards and determined their nutritional indices when fed on the key psylla pest of the system, Agonoscena pistaciae, in contrast to an alternative prey common on herbaceous plants in orchards, Aphis gossypii. RESULTS: Feeding experiments revealed that Oenopia conglobata contaminata and Adalia bipunctata may be more efficient as biocontrol agents for A. pistaciae than for A. gossypii, as A. bipunctata had a high efficiency of conversion of ingested food and a high relative growth rate and O. conglobata contaminata had a high consumption index on psylla prey. In contrast, the nutritional indices of Coccinella undecimpunctataaegyptica, Hippodamia variegata and Exochomus nigripennis suggest that A. gossypii was a more suitable host food. CONCLUSION: Where both the psyllids and the aphids occur in pistachio orchards, especially under conditions of unlimited access to A. gossypii, C. undecimpunctataaegyptica, H. variegata and E. nigripennis may prefer to move from psylla‐infested leaves of pistachio trees and travel to and stay on weeds to feed on A. gossypii. The value of using nutritional ecology as a means of understanding and predicting biocontrol outcomes and selecting better candidates for mass rearing is discussed. © 2018 Society of Chemical Industry Knowledge of the nutritional ecology of predators is important for the selection of efficient biocontrol agents. In this study, prey suitability for five ladybeetles was compared in a coccinellid–psyllid–aphid system. [ABSTRACT FROM AUTHOR]

Abstract: Functional response studies are often used to determine the suitability of predators as biocontrol agents. Ladybird beetles (Coleoptera: Coccinellidae) are often used for the control of crop pests such as aphids. However, most functional response studies on coccinellids compare a limited number of species at different life stages, temperatures or sexes. A large‐scale comparison of ladybird beetle functional responses is needed to evaluate the utility of these species as potential biocontrol predators and to understand the traits that influence the interaction strength between ladybird beetles and their prey. We compiled 158 ladybird beetle functional responses from 30 studies and tested for effects of taxa, traits, temperature and arena size on functional response parameters using linear mixed‐effects models. Our results show that functional response parameters (handling time and space clearance rate) are affected by predator stage, predator mass, prey type, temperature and arena size. Although complicated by interaction terms, space clearance rate generally increased with predator size, temperature and predator stage, while handling time decreased with predator size, temperature and predator stage. Coleopteran prey induced the highest handling times. Our results also show that experimental arena size has a large, consistent effect on space clearance rate. Arena size is more important in determining foraging rates at low prey densities than any other factor considered here, including predator mass and temperature. Efforts to use laboratory‐based functional response experiments to evaluate the efficacy of biocontrol predators are therefore confounded by the choice of arena size. Synthesis and applications. In addition to confirming known body mass and temperature effects, our study reveals previously unclear age‐related effects and the importance of prey types, which can be used to optimize biocontrol programmes. The arena size effect is unexpected and problematic because failure to account for arena size precludes accurate comparison of biocontrol predator effectiveness. We suggest managers and biocontrol practitioners re‐evaluate the efficacy of candidate biocontrol predators, perhaps by statistically controlling for arena size to minimize the influence of this widely unconsidered factor on functional response estimates. [ABSTRACT FROM AUTHOR]

Abstract: Thiamethoxam (TMX) is one of the most effective neonicotinoid insecticides for the control of green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), and various side effects can be expected in its natural enemies. The multicolored Asian lady beetle or harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is an important predator against M. persicae in greenhouses and fields. In this study, we evaluated the toxicity of TMX to H. axyridis and the effect on the functional response of this predator to M. persicae through three routes of exposure. Acute toxicity bioassays indicated that LC50 values of TMX on H. axyridis through direct residual contact (‘contact’), systemic application (‘systemic’), and leaf‐dip treatment (‘leaf‐dip’) were 18.99, 21.26, and 15.39 mg a.i. l−1, respectively. The hazard quotient indicated a potential hazard of this agrochemical regardless of the exposure routes. The mortality caused by the lowest rate, 2 mg a.i. l−1, was not significantly different compared with the control group. For the three routes of sublethal TMX exposure, the type‐II functional response was a good fit to the prey consumption of H. axyridis. Predation was most affected by leaf‐dip treatment, followed by contact and systemic treatments, which had similar effect. For all exposure routes, the predation capacity of the predator recovered quickly after transfer to untreated cabbage leaves. Thiamethoxam applied systemically was the least toxic to H. axyridis and did not affect the functional response of the predator. However, the sublethal effects of TMX through both contact and leaf‐dip application may reduce the population growth of H. axyridis and consequently impair the biological control of M. persicae by this predator. These results illustrate that the assessment of potential effects of TMX on H. axyridis is crucial to develop effective integrated pest management programs for M. persicae in China. [ABSTRACT FROM AUTHOR]