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Orius laevigatus (Fieber 1860) (Hemiptera: Anthocoridae) is a commercially used predator against soft-bodied pests in greenhouses. Many researchers have done studies on oviposition preference and hatching rate of O. laevigatus which are essential components for the mass-rearing studies of biocontrol agents. In addition, the effects of succulent plants and their potential to use for mass-rearing of O. laevigatus have not fully examined. This study has been done to determine the most suitable host plant for the oviposition preference of O. laevigatus at laboratory conditons between the year 2021 and 2022. No-choice and choice experiments were conducted for the five different succulent plants (Sedum nussbaumerianum Bitter, Kalanchoe daigremontiana Raym.-Hamet & H.Perrier, Kalanchoe blossfeldiana Poelln. (Saxifragales: Crassulaceae), Senecio barbertonicus Klatt. (Asterales: Asteraceae) and Aptenia cordifolia (L.f.) N.E.Br. (Caryophyllales: Aizoaceae) at 25ºC ± 2. %65 ± 10 relative humidity, and 16:8 L: D in climate rooms; According to the results of the No-choice experiment, Kalonchoe blossfeldiana, A. cordifolia, and S. barbertonicus were found the most successful host plant in terms of daily (5.14 ± 0.33, 6.73 ± 0.43, 6.19 ± 0.43) and total laid eggs (74.24 ± 5.70, 61.64 ± 4.51, 84.67 ± 5.50) and hatching ratio (75.01 ± 3.45, 74.40 ± 2.06, 64.26 ± 3.00). Out of these three host plants used for the choice experiment, Kalonchoe blossfeldiana was determined as the most suitable host plant in terms of daily and total laid eggs (3.42 ± 0.38, 33.28 ± 3.98), and hatching rate (22 72.40 ± 2.80 per cent). Consequently, K. blossfeldiana was found to be the most suitable host plant in terms of oviposition and hatching performance for the mas-rearing of O. laevigatus. [ABSTRACT FROM AUTHOR]

The exposure to arsenic and mercury in various insect trophic guilds from two mercury mining sites in Mexico was assessed. The two study sites were La Laja (LL) and La Soledad (LS) mines. Additionally, a reference site (LSR) was evaluated for LS. The terrestrial ecosystem was studied at LL, whereas both the terrestrial ecosystem and a stream called El Cedral (EC) were assessed at LS. The study sites are situated in the Biosphere Reserve Sierra Gorda (BRSG). Mercury vapor concentrations were measured with a portable analyzer, and concentrations of arsenic and mercury in environmental and biological samples were determined through atomic absorption spectrophotometry. Both pollutants were detected in all terrestrial ecosystem components (soil, air, leaves, flowers, and insects) from the two mines. The insect trophic guilds exposed included pollinivores, rhizophages, predators, coprophages, and necrophages. In LS, insects accumulated arsenic at levels 29 to 80 times higher than those found in specimens from LSR, and 10 to 46 times higher than those from LL. Similarly, mercury exposure in LS was 13 to 62 times higher than LSR, and 15 to 54 times higher than in LL. The analysis of insect exposure routes indicated potential exposure through air, soil, leaves, flowers, animal prey, carrion, and excrement. Water and sediment from EC exhibited high levels of arsenic and mercury compared to reference values, and predatory aquatic insects were exposed to both pollutants. In conclusion, insects from mercury mining sites in the BRSG are at risk. [ABSTRACT FROM AUTHOR]

Plants and herbivorous insects as well as their natural enemies, such as predatory and parasitoid insects, are united by intricate relationships. During the long period of co-evolution with insects, plants developed a wide diversity of features to defence against herbivores and to attract pollinators and herbivores' natural enemies. The chemical basis of insect-plant interactions is established and many examples are studied, where feeding and oviposition site selection of phytophagous insects are dependent on the plant's secondary chemistry. However, often overlooked mechanical interactions between insects and plants can be rather crucial. In the context of mechanoecology, the evolution of plant surfaces and insect adhesive pads is an interesting example of competition between insect attachment systems and plant anti-attachment surfaces. The present review is focused on mechanical insect-plant interactions of some important pest species, such as the polyphagous Southern Green Stinkbug Nezara viridula and two frugivorous pest species, the polyphagous Mediterranean fruit fly Ceratitis capitata and the monophagous olive fruit fly Bactrocera oleae. Their ability to attach to plant surfaces characterised by different features such as waxes and trichomes is discussed. Some attention is paid also to Coccinellidae, whose interaction with plant leaf surfaces is substantial across all developmental stages in both phytophagous and predatory species that feed on herbivorous insects. Finally, the role of different kinds of anti-adhesive nanomaterials is discussed. They can reduce the attachment ability of insect pests to natural and artificial surfaces, potentially representing environmental friendly alternative methods to reduce insect pest impact in agriculture. [ABSTRACT FROM AUTHOR]

Predation presents specific behavioral characteristics for each species, and the interaction between prey and predator influences the structuring of the food web. Concerning insects, predation can be affected in different ways, such as exposure to chemical stressors, e.g., pesticides. Therefore, analyses were carried out of the effects of exposure to insecticide fipronil and the herbicide 2,4-D on predation, parameters of food selectivity, and the swimming behavior of two neotropical predatory aquatic insects of the families Belostomatidae (giant water bugs) and larvae of Libellulidae (dragonfly). These predatory insects were exposed for 24 h to a commercial formulation of the chlorophenoxy herbicide, 2,4-D at nominal concentrations of 200, 300, 700, and 1400 μg L−1, and to a commercial formulation of the phenylpyrazole insecticide, fipronil at nominal concentrations of 10, 70, 140, and 250 µg L−1. In a control treatment, the insects were placed in clean, unspiked water. At the end of the exposure, the maximum swimming speed of the predators was evaluated. Afterward, the predators were placed in clean water in a shared environment for 24 h with several prey species, including the cladoceran Ceriodaphnia silvestrii, larvae of the insect Chironomus sancticaroli, the amphipod Hyalella meinerti, the ostracod Strandesia trispinosa, and the oligochaete Allonais inaequalis for 24 h. After this period, the consumed prey was counted. The results reveal that predators from both families changed prey consumption compared with organisms from the control treatment, marked by a decrease after exposure to fipronil and an increase in consumption caused by 2,4-D. In addition, there were changes in the food preferences of both predators, especially when exposed to the insecticide. Exposure to fipronil decreased the swimming speed of Belostomatidae individuals, possibly due to its neurotoxic effect. Exposure to the insecticide and the herbicide altered prey intake by predators, which could negatively influence the complex prey–predator relationship and the functioning of aquatic ecosystems in contaminated areas. [ABSTRACT FROM AUTHOR]

Sewage sludge can be used as the fertilizer of plants in the recovery of degraded areas. Sapindus saponaria L. (Sapindales: Sapindaceae) is a medicinal species native of America that lacks studies associated with its entomofauna. The objective was to determine, during 24 months, abundance, diversity, species richness and interactions of sap-sucking insects, leaf miners, phytophagous mites, predatory insects and spiders, and tending ants in S. saponaria saplings fertilized with or without with dehydrated sewage sludge. The hypotheses tested were: i) the numbers of phytophagous arthropods and some indices (e.g., diversity) are higher on fertilized saplings, which leads to an increase in the number of their natural enemies and tending ants, ii) groups of phytophagous arthropods compete with each other, and iii) phytophagous hemipterans are positively correlated with tending ants. The experimental design was a randomized complete block with two treatments (with and without dehydrated sewage sludge) and 24 replications, each with a S. saponaria sapling. Sapindus saponaria saplings fertilized with sewage sludge showed higher numbers of phytophagous arthropods Aleyrodidae (Hemiptera), and Lyriomyza sp. (Agromyzidae), abundance and species richness of phytophagous Hemiptera, tending ants Brachymyrmex sp., Ectatoma sp., Pheidole sp. and Pseudomyrmex termitarius Smith (Hymenoptera; Formicidae), spiders and greater abundance and species richness of predatory Sternorryncha (Hemiptera). Number of tending ants may have reduced those of Lyriomyza sp. and Cycloneda sanguinea (Coleoptera: Coccinellidae). Number of Aleyrodidae and Phenacoccus sp. were negatively correlated with those of C. sanguinea and Dolichopodidae and Chrysoperla sp., respectively. The number of Polybia sp. was positivelly correlated with that of Lyriomyza sp. mines. Diversity and species richness of phytophagous Hemiptera, tending ants and Sternorryncha predators were higher on S. saponaria saplings fertilized with dehydrated sewage sludge. The findings in this work demonstrate a greater balance between the different groups of arthropods on S. saponaria saplings fertilized with dehydrated sewage sludge, which can be very beneficial for biodiversity. [ABSTRACT FROM AUTHOR]

Despite their name, Wardian Cases were I not i invented by Nathaniel Bagshaw Ward. Keogh shows how widely the cases were used and concludes that the French "with the help of the Wardian case...had transformed their colonies" (p. 178). [Extracted from the article]

Insect predators are general feeders of sucking insects especially mealybugs, aphids, thrips due to their polyphagous needs. Two insect predators like Cryptolaemus montrouzieri as adult and Chrysoperla carnea as larva are important ones especially for Planococcus citri. It is crucial to know their potential for different nymph densities of P. citri under controlled conditions. For this study five varying nymph densities of P. citri of each nymphal instar at 8, 16, 32, 64 and 128 individuals for each predator were offered on daily basis to estimate their daily consumption. Mealybug individuals consumed and mortality of predatory insects was observed daily until instars changed to pupa in case of C. carnea and for period of five days in case of adult beetle. Results revealed that predation rate of both predators (C. carnea, C. montrouzieri) increased with increase in density of P. citri. The lowest number of P. citri of first instar (79, 111.45, 122.79) were devoured by first, second and third larval stages of C. carnea at the lowest density (8 P. citri/day). On other hand, the highest number of individuals (442, 637, 905 of P. citri) were consumed in high density treatment i.e., 128 P. citri/day) till pupation. Third larval stage of C. carnea exhibited higher predation rate (905 P. citri) than by first and second larval instars under the highest prey density (442, 637 P. citri). On other hand, C. montrouzieri adult devoured the least (2, 5, 4 P. citri of first, second and third instar) at the lowest density (8 P. citri/day), respectively but 39 of first, 29 of second and 8 of third instar were consumed at the highest density of 128 P. citri/day in five days. Predation rate of both predators decreased with increasing size of mealybugs. We suggest that both predators have significant predation potential to be utilized for the management of citrus mealybug in orchards. [ABSTRACT FROM AUTHOR]

The commercial utilization of genetically modified crops expressing Bacillus thuringiensis (Bt) insecticidal toxins requires careful assessment of the potential impact on non-target organisms. To assess the potential ecological impact of the Bt insect-resistant cotton variety A26-5 (expressing the Cry1Ac/1Ab protein), we tested whether there was transmission of Cry1Ac toxin through the food chain from cotton to the herbivorous prey Helicoverpa armigera (Hübner) through to the non-target predatory insect Arma chinensis (Fallou). A small amount of Cry1Ac protein was detected in H. armigera and A. chinensis, indicating that Cry1Ac could be transmitted to A. chinensis. However, no differences were found in survival rate, development, or fecundity of A. chinensis after treatment with Bt-fed or Bt-free H. armigera. Cry1Ac exposure did not affect detoxification genes expression in A. chinensis, which is likely related to our finding that Cry1Ac could not bind to receptors in the midgut. Taken together, these results show that the Bt cotton A26-5 has few, if any, toxic effects on A. chinensis. [ABSTRACT FROM AUTHOR]

Land-use change is one of the main drivers of global biodiversity loss, significantly affecting ecosystems. Small water bodies, such as ponds, are particularly vulnerable to these changes; these alterations can create new ecological conditions that affect species behaviors and interactions, particularly predator–prey dynamics. By causing unequal rates of phenological shifts among interacting species, land-use change can potentially disrupt ecological interactions. This study explores the spatiotemporal dynamics of anuran larvae communities and their potential predatory insects in temporary ponds within native forest and rural areas in the subtropical montane forest of Jujuy, Argentina. We conducted weekly surveys to characterize species diversity using diversity profiles based on Hill numbers and beta diversity partitioning method. We explored and compared species phenological patterns using circular statistical analyses. Results showed a slight impoverishment of tadpole communities in the rural habitat, while the predatory insects assemblages remained relatively unchanged. Rural land use influenced the phenology of anuran larvae and predatory insects, primarily through water availability variations. Understanding predator–prey interactions in modified environments is crucial for assessing and mitigating global biodiversity crises and ecosystem transformations. This study underscores the importance of natural predators in shaping ecosystems and influencing prey dominance under changing environmental conditions. [ABSTRACT FROM AUTHOR]

Context: Predatory insects contribute to the natural control of agricultural pests, but also use plant pollen or nectar as supplementary food resources. Resource maps have been proposed as an alternative to land cover maps for prediction of beneficial insects. Objectives: We aimed at predicting the abundance of crop pest predating insects and the pest control service they provide with both, detailed flower resource maps and land cover maps. Methods: We selected 19 landscapes of 500 m radius and mapped them with both approaches. In the centres of the landscapes, aphid predators – hoverflies (Diptera: Syrphidae), ladybeetles (Coleoptera: Coccinellidae) and lacewings (Neuroptera: Chrysopidae) – were surveyed in experimentally established faba bean phytometers (Vicia faba L. Var. Sutton Dwarf) and their control of introduced black bean aphids (Aphis fabae Scop.) was recorded. Results: Landscapes with higher proportions of forest edge as derived from land cover maps supported higher abundance of aphid predators, and high densities of aphid predators reduced aphid infestation on faba bean. Floral resource maps did not significantly predict predator abundance or aphid control services. Conclusions: Land cover maps allowed to relate landscape composition with predator abundance, showing positive effects of forest edges. Floral resource maps may have failed to better predict predators because other resources such as overwintering sites or alternative prey potentially play a more important role than floral resources. More research is needed to further improve our understanding of resource requirements beyond floral resource estimations and our understanding of their role for aphid predators at the landscape scale. [ABSTRACT FROM AUTHOR]

We assess the effects of changing land use and crop management on alfalfa insect abundance by comparing it in 50 alfalfa fields when they were inserted in landscapes with different proportions of arable crops and orchards. Land use in a buffer of 500 m was assessed, and alfalfa insect abundance was estimated with sticky yellow traps. The number of catches of several herbivores and predators was related to the proportion of landscape components and several field variables. Results indicated that the proportion of orchards in the buffer negatively affected the abundance of predators on alfalfa, likely because orchards treated with pesticides are a sink for predators moving in the landscape, among other possible causes. Other landscape variables such as noncrop habitats, winter cereals, and landscape diversity analysed by the Shannon index had a minor influence. Among field variables, field size influenced positively the abundance of insects on alfalfa, whereas alfalfa growth stage and age affected positively or negatively the different herbivores and predators. Of course, abundance of predators and prey was affected by the abundance of prey and predators, respectively. These findings suggest that a high proportion of intensively managed crops (orchards) in the landscape interferes with the role of alfalfa as a reservoir of predatory insects for adjacent crops and that the responses to local and landscape structures are temporal and species-specific as previously concluded for maize. Consequently, landscape and field management strategies to improve pest control must consider both types of variables as well as their changing influence when we modify them. [ABSTRACT FROM AUTHOR]

Schistosomiasis is one of the most important parasitic diseases in tropical and subtropical areas. Its prevalence is associated with the distribution of freshwater snails, which are their intermediate hosts. Thus, control of freshwater snails is the solution to reduce the transmission of this disease. This will be achieved by understanding the relationship between the snails and their habitats including natural enemies and associated aquatic plants as well as the factors affecting their distribution. In this study, Maximum Entropy model (MaxEnt) was used for mapping and predicting the possible geographic distribution of Bulinus truncatus snail (the intermediate host of Schistosoma haematobium), Odonata nymph (predatory aquatic insect), and Ceratophyllum demersum (the associated aquatic plant) in Egypt based on topographic and climatic factors. The models of the investigated species were evaluated using the area under receiver operating characteristic curve. The results showed that the potential risk areas were along the banks of the Nile River and its irrigation canals. In addition, the MaxEnt models revealed some similarities in the distribution pattern of the vector, the predator, and the aquatic plant. It is obvious that the predictive distribution range of B. truncatus was affected by altitude, precipitation seasonality, isothermality, and mean temperature of warmest quarter. The presence of B. truncatus decreases with the increase of altitude and precipitation seasonality values. It could be concluded that the MaxEnt model could help introducing a predictive risk map for Schistosoma haematobium prevalence and performing better management strategies for schistosomiasis. [ABSTRACT FROM AUTHOR]

Metarhizium anisopliae and Beauveria bassiana are commonly used entomopathogenic fungi, but their non-target effects over generalist predatory insects, which can contribute to pest control, are not well known. We studied the capacity of the social wasp Polistes myersi to detect the pathogens in either a powdered form or in Galleria mellonella larvae infected with either of the two pathogens offered as prey. The effects of these treatments were compared considering wasp behaviors such as prey preference, frequency, duration and transitions of both hunting and grooming behaviors. Additionally, the effects of each entomopathogenic fungus on the wasp's mortality were measured. Wasps seem not to detect the pathogens in powdered form but preferred healthy over infected larvae. Seventeen behavioral units for hunting and 34 for grooming were recognized. There were no differences in grooming frequency but there were significant differences on grooming duration, hunting behaviors and the patterns of transitions. Exposure of wasp colonies to either B. bassiana or M. anisopliae had no detectable impact on the mortality of adults, but mortality of larvae increased. For the first time, this study documented behavioral changes that indicated the capacity of social wasps to detect pathogens before physical contact and the display of hygienic strategies once contact occurs. The study also suggested a potential non-target effect of these entomopathogenic fungi on a generalist predator. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) has nectar containing modified stomates called nectaries that can be located on leaves, bracts or calyces. The nectar attracts some beneficial insects such as bees, but also predatory damaging insects such as heliothines and Lygus species. There is a naturally occurring mutation that eliminates the nectar containing nectaries and makes the cotton plants less attractive to insects. The nectariless (ne) trait is associated with a double recessive mutation of two genes (ne1 and ne2) on homeologous chromosomes 12 and 26. Expression of the trait can be variable and is also affected by environmental conditions. This makes accurately selecting for the trait based on phenotype difficult. This study identified SSR and SNP markers that can be used by breeders for marker assisted selection (MAS) of the nectariless trait. DNA markers associated with the genes conditioning the trait and used for MAS, will allow cotton cultivars to be easily developed that have decreased attractiveness to insects and reduce the need for insecticides, especially those harmful to beneficial insects such as honeybees. [ABSTRACT FROM AUTHOR]

In this long-term study we evaluated the diversity and seasonality of predatory insects (Diptera: Syrphidae and Asilidae) in Brachiaria decumbens monoculture and silvopastoral systems in Southeast Brazil. The study was conducted in Coronel Pacheco municipality, Minas Gerais state, Brazil, between February 2010 and January 2015. Insects were collected with malaise traps installed in both monoculture and silvopastoral systems. Specimen abundance, family diversity, seasonality assessed by circular analysis, the degrees of association between specimen number and climatic variables measured by Spearman's correlation, and the constancy and similarities of Syrphidae and Asilidae were analyzed in the monoculture and silvopastoral systems. Eleven species of hoverflies (Diptera: Syrphidae) were collected, five and three of which were exclusive to the silvopasture and monoculture, respectively. The number of specimens within the monoculture was significantly greater than that in the silvopasture. Twenty-four species of robber flies (Diptera: Asilidae) were collected, two of which were exclusive to the monoculture and eight to the silvopasture. The abundance of robber flies in the silvopasture was not significantly different from that in the monoculture. Syrphidae diversity was greater in the monoculture and was not significantly different from robber fly family diversity. Circular analysis revealed seasonality, with the distribution grouped during dry periods for hoverflies and dispersed for robber flies. Most hoverflies and robber flies were accidental in each of the systems. Further studies on the capacity of these predator species to act as biological control agents of pasture pests are required. This study presents important and promising results for understanding the dynamics of the Syrphidae and Asilidae community in monoculture and silvopastoral systems in Brazil. [ABSTRACT FROM AUTHOR]

Diplonychus rusticus (Heteroptera: Belostomatidae) is relatively a bigger sized tropical water insect serves as a main predator of mosquito larvae. In the present study, toxicity and effects of three different insecticides viz., temephos, lambda-cyhalothrin and cypermethrin was evaluated on D. rusticus. The results showed that the cypermethrin exhibited highest toxicity with lowest LC50 and LC90 values of 0.02 and 0.12 ppm on D. rusticus. Observations showed that the functional response greatly varied with all the three insecticides. The mean number of preys consumed at the density of 64 larvae was significantly different among the treatments. The mean longest handling time of 4.18 ± 0.34 and the mean lowest attack rate of 0.015 ± 0.008 were observed in lambda-cyhalothrin and cypermethrin treatments, respectively. The adult longevity of D. rusticus was found to be very less (42.33 ± 1.52 days) in cypermethrin treatments, whereas it was 113 ± 1.73 days and 120 ± 2.64 days in lambda-cyhalothrin and temephos insecticides, respectively at 0.01 concentration. The coupling behavior of the insect was noted to occur very rarely in all the three insecticide treatments. The total number of eggs layed was 16 eggs and 26 eggs in lambda-cyhalothrin and temephos treatments at 0.01 concentration, respectively. Furthermore, it was noted that there are no eggs were hatched (0%) from these egg clusters. These results indicate that the tested insecticides exhibited sub-lethal effects on the predatory insect D. rusticus. [ABSTRACT FROM AUTHOR]

Intraspecific differences in the dispersal propensity of animals have been linked to interindividual variation in inherent tendencies (i.e., personality or behavioral type) that influence multiple aspects of an individual's behavior. Studies linking dispersal propensity and personality often (1) focus on defining behavioral tendencies with a single behavioral trait rather than multiple, (2) do not recognize that invertebrates may have behavioral tendencies that influence dispersal, and (3) do not consider how the behavioral type of other individuals affects the dispersal propensity of an individual. We documented multiple foraging behaviors of an aquatic predatory insect (Notonecta irrorata) and found that Notonecta individuals differ in their inherent behavioral tendency (i.e., degree of boldness); all foraging behaviors were correlated such that riskier behaviors were exhibited by the same individuals. We conducted an experiment in which we varied which behavioral types of Notonecta were placed in outdoor pools (passive, bold or both types present) and quantified how long it took for individuals to disperse. Passive and bold individuals had a similar propensity to disperse but the dispersal propensity of each behavioral type was influenced by the behavioral type of other conspecifics present in the pool. Our work reveals that (1) invertebrates have inherent behavioral tendencies that vary among individuals but these tendencies do not necessarily impact all of the behavior displayed by the individual (i.e., impact foraging but not dispersal) and (2) the inherent behavioral tendency of other individuals with which an animal co-occurs can affect habitat patch dynamics such as predation, competition, or colonization. [ABSTRACT FROM AUTHOR]

The polyhedral inclusion bodies (PIBs) of Spodoptera littoralis nucleopolyhedrosis virus (SlNPV) were extracted from droppings of both the house sparrow Passer domesticus Raf. and the cattle egret Bubulcus ibis Bon. Due to the wide host range of the SlNPV, the extracted PIBs were bioassayed versus newly hatched larvae (L1) of S. littoralis, S. exigua, Trichoplusia ni, and Autographa circumflexa belonging to the insect fauna of the Egyptian clover Trifolium alexandrinum L. and the greater wax moth Galleria mellonella. Mortality of treated neonates of the 5 tested insect species ranged between 80 and 100 % after 7 days from ingesting the PIB-contaminated diet. Feeding nymphs and adults of the earwig Labidura riparia Pallas on S. littoralis larvae infected with the nuclear polyhedrosis virus (SlNPV) passed viable PIBs in feces which were extracted and bioassayed versus lepidopteran larvae of L1. All of the virus-treated 5 lepidopteran species became infected with the virus and showed mortality of 44–96% at the 7th day post ingestion of the extracted PIBs. On the other hand, feces extract of the 3rd larval instar (L3) of the lacewing Parachrysopa pallens (R.) fed on the virus-diseased larvae of S. littoralis caused no mortality when assayed versus the 5 tested lepidopteran larvae proving absence of viable PIB polyhedra that might be due to the mode of larval feeding by external digestion of its host contents including the polyhedra. Results explain the potential role played by insectivorous birds in spreading the nucleopolyhedrosis viruses in the agroecosystem as well as certain predatory insects. [ABSTRACT FROM AUTHOR]

Global pollution of mercury (Hg) threatens ecosystem and human health. We measured total Hg (THg) and monomethylmercury (MMHg) concentrations in filter-feeding blackfly (Simulium spp.) larvae in the inflows and the outflows of six boreal lakes with no Hg point source pollution. THg in the larvae ranged from 0.03 to 0.31 mg kg−1 dw and MMHg between 0.02 and 0.25 mg kg−1 dw. The proportion of MMHg in the larvae was 74 ± 0.16% and ranged from 43 to 98% of THg, the highest proportions being comparable to those typically found in aquatic predatory insects and fish. We compared the larvae MMHg concentrations to river water quality, catchment land-use, and to size-adjusted lake pike THg data. Two of the investigated catchments have been affected by a multimetal biomine since 2008 and were characterized by higher conductivity and higher urban land-use activity. Larvae THg and MMHg concentrations were higher in the lake inflows than in outflows and associated with water conductivity and catchment land-use activity. Lake pike THg concentrations were highly correlated to lake outflow blackfly larvae MMHg concentrations. Our data illustrate that blackfly larvae take up high percentage of THg that is MMHg, which in turn is available for higher consumers in aquatic and terrestrial food webs. [ABSTRACT FROM AUTHOR]

Distance between habitats may impact the composition and corresponding interactions between trophic levels. Mutualistic networks, such as those of plants and pollinators tend to have a core set of properties that often relate to the resilience of the community, or the ability of the community to retain function and structure after a disturbance. Furthermore, network structure is highly dependent on the number of specialists and generalists; however, it is unclear how different groups of species with various life-history strategies influence network structure. In this study, we evaluated how the composition of plants and pollinators within 16 oak-savanna sites changed across a latitudinal gradient. In addition, we evaluated how the abundance of different groups of plants and pollinators affected network metrics related to resilience. We found that the composition of plants and pollinators varied between ecoregions, while pollinator composition further varied with habitat characteristics. Network metrics displayed no spatial pattern but were related to the abundance of several pollinator groups. Above-ground nesting insects had a positive relationship with nestedness and a negative relationship with modularity, while predatory larvae had a negative relationship with modularity. Thus, above-ground nesting insects and predatory larvae could be expected to increase network resilience. This study emphasizes how spatial scales can influence species compositions, which in turn affects the structure of interactions in the community with implications for resilience. [ABSTRACT FROM AUTHOR]

Chrysoperla externa and Coleomegilla quadrifasciata are important biological control agents in peach orchards. However, orchard management with these predatory insects is viable only by using selective agrochemicals. The objective of this study is to evaluate the toxicity of nine agrochemicals used in peach orchards in larval and adult stages of the C. externa and C. quadrifasciata in laboratory conditions. The bioassays followed the methodologies proposed by the International Organization for Biological and Integrated Control (IOBC). Larvae and adults of C. externa and C. quadrifasciata were exposed to the dry residues of these products. Lethal and sublethal effects were evaluated in bioassays with the larval and adult stages of both predators. The agrochemicals were classified according to the IOBC guidelines. The insecticide chlorantraniliprole was harmless (class 1) to the larval stage of C. externa and C. quadrifasciata. Azadirachtin, copper 25% + calcium 10%, and deltamethrin were harmless to the adult stage of both insect species. The organophosphates fenitrothion and malathion were harmful (class 4) to both species in the larval and adult stages and should not be used in peach orchards. Therefore, this study demonstrates the importance of toxicity and the lethal and sublethal effects of these agrochemicals to better determine their compatibility with IPM in peach production. [ABSTRACT FROM AUTHOR]

The aim of this study was to test the effects of agricultural land use on benthic insect population body-mass and community biomass size spectrum. Agricultural land use effects were assessed by conducting a reciprocal transfer experiment between two stream reaches exposed to differing intensities of row crop and livestock agricultural activity representing best attainable and highly developed agricultural land use scenarios. We found that transferred insect communities showed no change in richness, abundance, distribution or biomass, indicating that exposure to increased agricultural intensity did not have selective lethal effects on transferred benthic insect communities. However, populations of Ephemerellidae and Hydropsyche demonstrated an increase and decrease, respectively, in body-mass following the transfer to the best attainable agriculture site. Furthermore, the community biomass size spectrum at the best attainable agriculture site contained large, predatory insects not found at the intensive agriculture site. Our findings suggest that taxon-specific body-mass and biomass size spectra have the potential to detect environmental effects prior to long-term community changes. Further research is needed to explore the mechanisms by which changes in the biomass size spectrum link agricultural intensity to shifts in benthic insect community structure. [ABSTRACT FROM AUTHOR]

Population fluctuations of Pseudococcus cryptus Hempel (Hemiptera: Pseudococcidae) in citrus, role of the parasitoids, within total parasitism and levels of sooty-mold growth due to honeydew secretion of the pest on trees were revealed during the years of 2006–2009 in Samandağ district (Hatay). Additionally, populations of main predatory insects followed the prey populations during the growing season. In 2006, P. cryptus density was 3.41 egg clusters/leaf, 91.80 nymph + adult/leaf and the highest overall parasitism rate for was 41.63%. These figures were 2.23, 54.65 and 38.56%, in 2007; 3.33, 53.00 and 39.22%, in 2008; 4.18, 48.05 and 38.89%, in 2009, respectively. According to the samplings done in citrus orchards throughout the 3 years, P. cryptus populations started to rise in April, reaching the highest densities especially in June–July; and its population tended to decline starting from August due to natural enemies. The mean parasitization ratios as the proportion of the total parasitism were 68.15, 69.48, 70.55 and 71.06% for C. purpurea in 2006, 2007, 2008 and 2009, respectively. These figures were 14.58, 13.25, 12.94 and 12.58% for L. abnormis; 8.25, 7.35, 7.85 and 6.25% for A. pseudococci and 9.02, 9.92, 8.66 and 10.11% for P. muscarum. Levels of sooty-mold growth due to honeydew secretion by P. cryptus varied from 3.42/4 to 2.06/4 on citrus trees from 2006 to 2009, respectively. [ABSTRACT FROM AUTHOR]

We conducted a review of published information on Tuta absoluta parasitoids for the Neotropical region to (1) corroborate species records, (2) analyze associations including the T. absoluta, other insect and plant hosts and (3) identify research directions for enhancing their use as biological control agents. The literature review shows more than 50 species or morphospecies of Hymenoptera associated with T. absoluta, but less than a half (23) could be confirmed as parasitizing T. absoluta. Erroneous reports or invalid names of species, two new species records were found. Over a 100 pests and non-economically important insect and cultivated and non-cultivated plants directly or indirectly interact with T. absoluta in the region. Four T. absoluta parasitoid species include in their host range predatory insects or act as hyperparasitoids, a negative feature considered for a biological control agent. Five larval parasitoids have a narrow host range and could be considered for classical biological control programs in the areas of new invasion. Six Trichogrammatidae species are commercially used in various countries; of those, T. minutum and T. pretiosum are considered to be moderately generalist, being able to exploit several insect hosts. Apart from Apanteles gelechiidivoris and Pseudapanteles dignus, other native species have been the subject of field studies as biological control agents. The review presented here provides useful insights for identifying species that deserve further evaluation as T. absoluta biological control agents through augmentative or conservation strategies in South America, as well as for potential classical biological control programs in other continents. [ABSTRACT FROM AUTHOR]

The predatory bug, Anthocoris minki Dohrn (Hem.: Anthocoridae), is an important predator of ash psyllid, Psyllopsis repens Loginova (Hem.: Psyllidae) and is very abundant on ash trees (Fraxinus excelsior L.) in Mashhad region, Iran. Functional response parameters, handling time and searching efficiency are of particular value in understanding feeding behavior of a predator. The type of the functional response and the rates of its parameters are influenced by different factors. In this study, the functional responses of A. minki to densities of P. repense at different temperatures (15, 24 and 30 °C), prey instar (2nd and 4th instar nymphs), developmental stage of predator (4th nymph and adult) and sex of predator (male and female) were investigated. The effects of predator densities and interference on searching efficiency were estimated. Logistic regression and nonlinear least- square regression were used to estimate the type of the functional response and its parameters, respectively. In order to determine the per capita searching efficiency and interference coefficient, Nicholson's model and linear regression were used. The results showed a type II functional response on all experiments except of adult predators to 2nd instar nymphs of prey which exhibited a type III functional response. The greatest value of attack rate and the shortest handling time were seen at 30 °C. The per capita searching efficiency decreased as densities increased but there was no significant difference. The laboratory results suggest that A. minki has potential to control P. repens on ash trees but further research is needed under field conditions. [ABSTRACT FROM AUTHOR]

Holding food bimanually for biting off pieces with the mouth is a behavior performed by several groups of insects with predatory or plant eating habits. Locusts often grab longer pieces of loose or dangling grass with their forelegs and eat it in repetitive movement patterns by holding the blade vertical between the opposed tarsal pads. Head and body remain still while the mouthparts bite off and ingest suitable pieces. The forelegs alone raise and guide the grass blade precisely between the mandibles that bite across it in series of 1–5 consecutive biting bouts. A typical series has 3–4 bouts and cuts a 5-7 mm wide blade completely. The remaining edge of the grass blade is skewed at about 30–60 degrees. Consecutive series start with biting into the upper edge of the blade after the forelegs have pulled it nearer and under the mouthparts. During the first bites both legs extend forward moving the opposed tarsi along the blade and renew their grip more outward. The whole stereotyped but adaptive pattern involves only forelegs and mouthparts, while the palps continuously monitor the food's shape and relative position to the mouthparts. In this first study of bimanual ("bi-tarsal") food handling in insects the standard sequence of movements and muscle coordination of the forelegs is described for locusts. This repetitive behavior is an example of object-centered coordination between several appendages within the peripersonal space of animals. [ABSTRACT FROM AUTHOR]

Evidence for the adaptive value of oviposition site selection in terms of increased offspring fitness is rare in predatory insects. We tested this in the damselfly Lestes macrostigma that prefers the plant Bolboschoenus maritimus. We carried out two experiments with shoots containing eggs: we flooded (1) some shoots of the same type (i.e. combination of species and desiccation state) at different dates and (2) different shoot types at the same date. Earlier flooding increased hatching success. Because B. maritimus grows in deeper parts of temporary ponds, it is flooded before other plants after the drought season, suggesting that adult oviposition site selection is driven by lower egg desiccation risk. Independently of flooding date, hatching success was higher and larvae hatched earlier when eggs were laid in B. maritimus. Faster embryonic development enhances chances to complete larval development before pond desiccation and reduces costs associated with time stress. Offspring higher fitness was more constant between shoots of B. maritimus compared to the other types of shoot, suggesting that laying eggs in one shoot of this plant leads offspring to high fitness more surely. Our results indicate that adults choose oviposition plants maximizing offspring fitness (higher hatching success and faster embryonic development). [ABSTRACT FROM AUTHOR]

The backswimmer Buenoa tarsalis (Hemiptera: Notonectidae) is a naturally occurring predator of immature stages of mosquitoes. These aquatic predators can suffer from non-targeted exposure to insecticides that are commonly used in aquatic environments to control mosquitoes. Here, we evaluated whether insecticide formulations containing the bacterium Bacillus thuringiensis var. israelensis (Bt) or the organophosphate pirimiphos-methyl would affect the survival and the predatory abilities of B. tarsalis. First, we conducted survival bioassays to estimate the median survival time (LT) of B. tarsalis when exposed to Bt-based insecticide (at 0.25 and 25 mg a.i./L) and pirimiphos-methyl (at 1, 10 and 1000 mg a.i./L). The highest concentrations of the insecticides were equivalent to the label-recommended field rates. Second, the predatory abilities of B. tarsalis exposed to insecticides were evaluated at three prey densities (3, 6 and 9 mosquito larvae/100 mL water) just after insecticide exposure or after a 24 h recovery time. While the survival of B. tarsalis was significantly reduced with pirimiphos-methyl concentrations ≥10 mg a.i./L, the Bt-exposed predators exhibited similar survival as unexposed predators. Interestingly, after a recovery time of 24 h, B. tarsalis sublethally exposed to pirimiphos-methyl or Bt-based insecticide consistently killed more A. aegypti larvae (at the intermediate density) than unexposed predators. However, for the without-recovery bioassays, the pirimiphos-methyl-exposed predators exhibited reduced predatory abilities at the lowest prey density. Because they do not reduce the survival or the predatory abilities of B. tarsalis, Bt-based insecticides can be considered a safe insecticide to use in the presence of backswimmers. [ABSTRACT FROM AUTHOR]

The taxonomy of free-living adults and heteromorphic parasitic larvae of Parasitengona mites has in the past been treated independently resulting in a double classification. Correct linkage of names still remains unknown for many species. A holistic understanding of species is imperative for understanding their role in ecosystems. This is particularly true for groups like parasitengone mites with a radically altered lifestyle during development-parasitic to predatory. Here, we infer linkages of three nominal species of Erythraeus, using matching with 28S DNA sequence data from field-collected specimens and through laboratory rearing. The general mixed Yule coalescent method (GMYC) was used to explicitly test if field-collected specimens representing heteromorphic life instars were conspecific. The field-collected larvae were allocated to adults of Erythraeus cinereus and Erythraeus regalis, respectively. Laboratory rearing of the same two species confirmed the matching done by DNA. Rearing was also successful for Erythraeus phalangoides after eggs were treated to an imitated winter diapause. This integrative taxonomic approach of molecular, morphological, and rearing data resulted in the following synonyms: E. phalangoides (De Geer, 1778) [= Erythraeus adrastus (Southcott, 1961), syn. nov.], E. cinereus (Dugès, 1834) [= Erythraeus jowitae Haitlinger, 1987, syn. nov.], and E. regalis (C.L. Koch, 1837) [= Erythraeus kuyperi (Oudemans, 1910), syn. nov., = Erythraeus gertrudae Haitlinger, 1987, syn. nov.]. The molecular evidence confirmed the separate identity of three further members of the genus. We provide redescriptions of E. phalangoides, E. cinereus, and E. regalis after modern standards, and neotypes are designated. [ABSTRACT FROM AUTHOR]

Genetic variations of the two coccinellid predators; Coccinella undecimpunctata L. and Hippodamia variegata (Goeze) within and between distant populations in Saudi Arabia were studied by partial sequencing of three mitochondrial genes i.e., COI gene and ribosomal 12S and 16S. Samples were collected from four distant localities for C. undecimpunctata (Jazan, Jeddah, Taif and Madinah) and from six distant localities for H. variegate (Jazan, Jeddah, Taraba, Madinah, Riyadh and Tabouk). Concatenated sequences (1354 bp) were manipulated by three analytical methods (maximum parsimony, neighbor-joining and maximum-likelihood) producing one fixed tree. The A, C, G and T base compositions were 36.8, 14.5, 10.5 and 38.2%, respectively. The pair-wise genetic distances (D) among the studied populations ranged from 0.0013 to 0.0041 in case of C. undecimpuntata and from 0.0048 to 0.0128 in case of H. variegata. Tree topology did not discriminate among and within populations of both species, except of Tabouk population for H. variegata which showed one cluster of all individuals. It may be concluded that the studied populations of both coccinellids showed low genetic variability. Therefore, this confirms that it has not structured along geographically separated populations in both the studied species; the genetic variability was slightly affected by either fragmentations or ecological factors. [ABSTRACT FROM AUTHOR]

Adult emergence rates of released Calosoma sycophanta L. (Coleoptera: Carabidae) larvae under field conditions were determined in Turkey for three years (2012-2014). Directions and altitudes of the area that received released larvae were important factors affect adult emergence rates. Above 501 m, at the northern direction in the research areas had higher adult emergence rates compared to the southern one. Below 500 m at southern direction, adult emergence rates were higher than at north. Soil depth didn’t affect emergence rates of the adult beetles. According to the results, pupation average preferential depth was 12.6 cm (7.5-15.4 cm) as about 35% of the larvae, used in the study developed to adults. Sex ratio was 42% males and 58% females. The northern direction had higher female adults compared to the southern one (North ♀66, ♂34% and South ♀49.75, ♂50.25%). At 0-500 m more significant adults was recorded than at 501-1000 m. [ABSTRACT FROM AUTHOR]

Phytoseiulus longipes Evans (Mesostigmata: Phytoseiidae) is an exotic predator widely used in biological control programs for the red spider mite Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) in East Africa. However, little is known about the cues mediating this prey/predator interaction. Here, we performed behavioral assays to test the involvement of visual, vibratory, and olfactory cues using a combination of dead/living insects enclosed in either perforated or non-perforated transparent/opaque capsules. We monitored insect responses with a video tracking system and analyzed the data with Ethovision software. Our results showed avoidance behavior of T. evansi in the presence of live P. longipes through visual, vibratory, and olfactory cues. P. longipes was attracted by vibratory and olfactory cues emitted by T. evansi. The composition of volatiles from T. evansi was identified by GC/MS as methyl salicylate (MeSA), linalool, β-caryophyllene, octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid. Our behavioral assays with predatory mites in a Y-tube olfactometer revealed that among the identified volatiles, only MeSA, linalool, and MeSA + linalool attracted P. longipes. The implications of these findings for the control of T. evansi are discussed. [ABSTRACT FROM AUTHOR]

The predator satiation and predator dispersal hypotheses provide alternative explanations for masting. Both assume satiation of seed-eating vertebrates. They differ in whether satiation occurs before or after seed removal and caching by granivores (predator satiation and predator dispersal, respectively). This difference is largely unrecognized, but it is demographically important because cached seeds are dispersed and often have a microsite advantage over nondispersed seeds. We conducted rodent exclosure experiments in two mast and two nonmast years to test predictions of the predator dispersal hypothesis in our study system of yellow-necked mice ( Apodemus flavicollis) and European beech ( Fagus sylvatica). Specifically, we tested whether the fraction of seeds removed from the forest floor is similar during mast and nonmast years (i.e., lack of satiation before seed caching), whether masting decreases the removal of cached seeds (i.e., satiation after seed storage), and whether seed caching increases the probability of seedling emergence. We found that masting did not result in satiation at the seed removal stage. However, masting decreased the removal of cached seeds, and seed caching dramatically increased the probability of seedling emergence relative to noncached seeds. European beech thus benefits from masting through the satiation of scatterhoarders that occurs only after seeds are removed and cached. Although these findings do not exclude other evolutionary advantages of beech masting, they indicate that fitness benefits of masting extend beyond the most commonly considered advantages of predator satiation and increased pollination efficiency. [ABSTRACT FROM AUTHOR]

Typhlodromus pyri Scheuten and Euseius finlandicus (Oudemans) are important predators of phytophagous mites. The present laboratory study aimed to determine whether both species can develop and reach maturity feeding on spider mites occurring on willows, i.e., Schizotetranychus schizopus (Zacher), Schizotetranychus garmani Pritchard & Baker, and Tetranychus urticae Koch, and on Brassica napus L. pollen. The predators' development, reproduction and demographic parameters were significantly affected by diet. The data suggest that rape pollen can be useful in mass rearing of E. finlandicus but is completely unsuitable as alternative food for T. pyri. Short development time and high values of population parameters achieved by T. pyri feeding on larvae and protonymphs of S. schizopus and by E. finlandicus feeding on juvenile stages of S. garmani indicate great suitability of these preys as food for the phytoseiids, and make both predatory species promising biocontrol agents in spider mite control on willows. [ABSTRACT FROM AUTHOR]

Predatory behaviour is plastic towards different prey. However, prey differ in their defenses and predators should adjust in order to successfully subdue it. The variation in predatory behaviour could be either innate or developed from experiences. A feasible way to tease these factors apart is by studying inexperienced individuals. Here, I tested if the behaviour of inexperienced predators is different towards two prey types and if it correlates with the behaviour of the prey. I fed naïve spiderlings of the sheet weaver cellar spider Physocyclus globosus (Pholcidae) with either fruit flies or ants as prey (potential extremes in difficulty). I found that, regardless of prey type, individuals that exhibited active defensive behaviour (longer time twisting, moving legs and body segments) elicited a more intense predatory behaviour by the spiderlings (longer time touching and wrapping the prey, and giving more bites). Ants were often more difficult prey than flies, even damaging the spiderling's leg in five trials. A successful attack to difficult prey was associated with increased handling time of additional silk needed to immobilize it. The differences in the predatory behaviour showed by P. globosus spiderlings suggest plasticity since their first attack. This plasticity would be adaptive for naïve predators of any taxa that encounter a wide diversity of prey. [ABSTRACT FROM AUTHOR]

The western flower thrips is an omnivorous insect that consumes both leaf tissue and spider mite eggs. For this reason, these thrips are often described as 'opportunistic predators' of spider mites. Several studies have shown that western flower thrips are often found in association with spider mites, and the development time of thrips decreases and their survivorship increases when they consume spider mite eggs. We tested the hypothesis that thrips larvae may respond to chemical cues from spider mites, and that they may modify their prey-searching behavior when these spider mite-induced cues are present. We prepared hexane extracts from: 1) webbing of spider mites isolated from maize leaves, 2) webbing produced by spider mites inside an empty glass tube to exclude any plant-derived cues from the extract, and 3) spider mite cuticle extracts. These three extracts were subsequently applied in droplets to one-half of filter papers, and hexane alone was applied in droplets to the other half. We showed that residence time of thrips larvae was higher on filter paper with spider mite webbing extract, especially when the extract originated from spider mites isolated in glass tubes. In the presence of webbing extracts, we also observed: 1) a decrease in velocity, 2) an increase of angular velocity and 3) an increase in time immobile. Extracts from spider mite cuticle only increased velocity and proportion of time immobile of the thrips larvae. Our results suggest that chemical cues from spider mite webbing induce an arrestment response and play an important role in the non-random search behavior of thrips larvae searching for eggs on spider mite infested plant leaves. [ABSTRACT FROM AUTHOR]

Pollen is offered as alternative or supplementary food for predacious mites; however, it may vary in its nutritional value. Body weight appears a representative parameter to describe food quality. Thus, we assessed the body weight for adults of the generalist mites Amblyseius swirskii, Amblydromalus limonicus, and Neoseiulus cucumeris reared on 22, 12, and 6 pollen species, respectively. In addition, A. swirskii and A. limonicus was reared on codling moth eggs. In all mite species, female body weight was higher than that of males, ranging between 4.33 and 8.18 µg for A. swirskii, 2.56-6.53 µg for A. limonicus, and 4.66-5.92 µg for N. cucumeris. Male body weight ranged between 1.78 and 3.28 µg, 1.37-3.06 µg, and 2.73-3.03 µg, respectively. Nutritional quality of pollen was neither consistent among the mite species nor among sex, revealing superior quality of Quercus macranthera pollen for females of A. swirskii and Tulipa gesneriana pollen for males, Alnus incana pollen for females of A. limonicus and Aesculus hippocastanum pollen for males, and Ae. hippocastanum pollen for both sexes of N. cucumeris. The results are discussed against the background of known or putative pollen chemistry and mite's nutritional physiology. [ABSTRACT FROM AUTHOR]

The fish Gambusia affinis (Baird and Girard, 1853) was used under laboratory conditions to evaluate its efficacy as a predator against different stages of the snail, Biomphalaria pfeifferi, the intermediate host of human Schistosoma mansoni. Results showed that G. affinis was a voracious predator towards egg-masses and neonate snails with a shell diameter length (SDL) of up to 3.5mm, as well as of adult snails with a SDL greater than 3.5mm. The results showed also that G. affinis had a significant impact on B. pfeifferi snail populations. However, long term studies under natural field conditions are needed to support these results. [ABSTRACT FROM AUTHOR]

Predatory insects often feed on plants or use plant products to supplement their diet, creating a potential route of exposure to systemic insecticides used as seed treatments. This study examined whether chlorantraniliprole or thiamethoxam might negatively impact Coleomegilla maculata and Hippodamia convergens when the beetles consumed the extrafloral nectar of sunflowers grown from treated seed. We reared both species on eggs of Ephestia kuehniella and then switched adult H. convergens to a diet of greenbugs, Schizaphis graminum, in order to induce oviposition in this species. Excised sunflower stems, either treated or control and refreshed every 48 h, were provided throughout larval development, or for the first week of adult life. Exposure of C. maculata larvae to chlorantraniliprole and thiamethoxam applied as seed treatments delayed adult emergence by prolonging the pupal period. When adults were exposed, thiamethoxam reduced the preoviposition period compared to chlorantraniliprole, whereas the latter treatment cause females to produce fewer clutches during the observation period. Larvae of C. maculata did not appear to obtain sufficient hydration from the sunflower stems and their subsequent fecundity and fertility were compromised in comparison to the adult exposure experiment where larvae received supplemental water during development. Exposure of H. convergens larvae to thiamethoxam skewed the sex ratio in favor of females; both materials reduced the egg viability of resulting adults and increased the period required for eclosion. Exposure of H. convergens adults to chlorantraniliprole reduced egg eclosion times compared to thiamethoxam and exposure to both insecticides reduced pupation times in progeny. The results indicate that both insecticides have negative, sublethal impacts on the biology of these predators when they feed on extrafloral nectar of sunflower plants grown from treated seed. [ABSTRACT FROM AUTHOR]

Acaricides may interfere with a myriad of interactions among arthropods, particularly predator-prey interactions. The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), and its phytoseiid predator, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae), provide an opportunity to explore such interference because the former is a key coconut pest species that requires both predation and acaricide application for its management. The objective of the present study was to assess the effect of the acaricides abamectin, azadirachtin and fenpyroximate on the functional response of N. baraki to A. guerreronis densities. The following prey densities were tested: 5, 10, 20, 40 and 80 preys. The type of functional response and prey handling time ( Th) were not altered by the acaricides. However, the attack rate ( a′) was modified by abamectin and fenpyroximate, and the consumption peak was reduced by abamectin. All of the acaricides allowed for the maintenance of the predator in the field, but exposure to abamectin and fenpyroximate compromised prey consumption. [ABSTRACT FROM AUTHOR]

Cyrtorhinus lividipennis Reuter, an important predator of rice planthopper and leafhoppers, plays a significant role in the integrated pest management (IPM) of rice pest. However, chemical control remains a major strategy against rice pests. Insecticide risk assessment should include sublethal effects on non-target organisms before being included in IPM schemes. We examined the sublethal effects of four insecticides, triazophos, deltamethrin, chlorantraniliprole, and pymetrozine on C. lividipennis. The results demonstrated that sublethal concentrations of deltamethrin (LC and LC) disrupted the orientation behavior of C. lividipennis, but sublethal concentrations of triazophos (LC and LC), chlorantraniliprole, and pymetrozine (the recommended field rate and half field rate) had no impact on the behavioral response of surviving predators. The mean consumption of C. lividipennis treated with sublethal concentrations of triazophos decreased approximately 18-35 % compared to that of untreated ones. Sublethal concentrations of deltamethrin also reduced the mean consumption of C. lividipennis, but sublethal concentrations of chlorantraniliprole and pymetrozine exhibited no influence on the predatory capability of the predator. Significant reductions in pepsin activity were observed in triazophos and deltamethrin treatments but not in chlorantraniliprole and pymetrozine treatments. Our results indicated that triazophos and deltamethrin exerted sublethal effects, such as disturbed foraging ability, reduced predatory capacity, and decreased pepsin activity on C. lividipennis, and chlorantraniliprole and pymetrozine were regarded as safer to this predator. [ABSTRACT FROM AUTHOR]

The selection of oviposition sites by syrphids and other aphidophagous insects is influenced by the presence of con- and heterospecific competitors. Chemical cues play a role in this selection process, some of them being volatile semiochemicals. Yet, little is known about the identity and specificity of chemical signals that are involved in the searching behavior of these predators. In this study, we used olfactometer bioassays to explore the olfactory responses of gravid females and larvae of the syrphid Sphaerophoria rueppellii, focussing on volatiles from conspecific immature stages, as well as odors from immature stages of the competing coccinellid Adalia bipunctata. In addition, a multiple-choice oviposition experiment was conducted to study if females respond differently when they can also sense their competitors through visual or tactile cues. Results showed that volatiles from plants and aphids did not affect the behavior of second-instars, whereas adult females strongly preferred odors from aphid colonies without competitors. Odors from conspecific immature stages had a repellent effect on S. rueppellii adult females, whereas their choices were not affected by volatiles coming from immature heterospecific A. bipunctata. The results imply that the syrphid uses odors to avoid sites that are already occupied by conspecifics. They did not avoid the odor of the heterospecific competitor, although in close vicinity they were found to avoid laying eggs on leaves that had traces of the coccinellid. Apparently adult syrphids do not rely greatly on volatile semiochemicals to detect the coccinellid, but rather use other stimuli at close range (e. g., visual or non-volatile compounds) to avoid this competitor. [ABSTRACT FROM AUTHOR]

The demographic parameters and the larval aphid consumption of the predatory coccinellids Hippodamia variegata (Goeze) and Ceratomegilla undecimnotata (Schneider) were examined at five constant temperatures (17, 20, 23, 26, and 29 °C). The same parameters were determined for Coccinella septempunctata L. at 23 °C. A red Myzus persicae nicotiannae Blackman clone reared on tobacco leaves was used as prey. Preimaginal development of H. variegata and C. undecimnotata ranged from 12.4 to 40.6 days and 14.4 to 48.5 days at 17 °C to 29 °C, respectively. The corresponding thermal summation constants were 211 and 256 DD (day-degrees). Total and mean daily larval consumption at 26 °C were 84.2 and 8.7 aphids, for H. variegata and 129.1 and 9.4 aphids, for C. undecimnotata, respectively. At 23 °C, the mean fecundity of H. variegata, C. undecimnotata and C. septempunctata was 882, 656 and 586 eggs, respectively. The duration of the oviposition periods was 47.6, 50.4 and 73.4 days, respectively. The demographic parameters calculated for H. variegata, C. undecimnotata and C. septempunctata, were as follows: intrinsic rate of increase ( r) 0.129, 0.084, and 0.061 female/female/day; mean generation time (T) 42.4, 59.1, and 69.3 days; net reproductive rate (R) 241.9, 142.7, 67.3 female/female; and population duplication time (DT) 5.4, 8.3, and 11. 4 days. Total aphid consumption by a pair of adult male and female was 2381 aphids in H. variegata and 3242 aphids in C. undecimnotata. The possible role of the three predator species as biocontrol agents is discussed. [ABSTRACT FROM AUTHOR]

The influence of ground cover plants on the ecosystem service of weed seed predation by crickets (Orthoptera: Gryllidae) was evaluated on paddy field levees in Japan in 2010 and 2011. We compared the activity density of crickets and invertebrate seed predation on Lolium multiflorum, a non-native grass weed, among five vegetation types grown on paddy levees: the ground covers Eremochloa ophiuroides, Phyla canescens, Phlox subulata, and Zoysia japonica, and weedy vegetation dominated by Digitaria ciliaris. Camera recordings showed that crickets were the predominant invertebrate seed predators. Cricket density tended to be higher on levees with E. ophiuroides, Phyla canescens, and Phlox subulata [5.8-7.2 individuals/trap/day (individuals/trap/d) (2010); 5.4-7.6 individuals/trap/d (2011)] than in those with Z. japonica and weedy vegetation [1.0-2.2 individuals/trap/d (2010); 2.2-3.2 individuals/trap/d (2011)]. Invertebrate seed predation on levees with Phyla canescens and Phlox subulata tended to be relatively high in both years. These results suggest that E. ophiuroides, Phyla canescens, and Phlox subulata can increase cricket density, and that Phyla canescens and Phlox subulata, in particular, can stably enhance weed seed predation on paddy field levees. [ABSTRACT FROM AUTHOR]

Predators can affect prey in two ways-by reducing their density (consumptive effects) or by changing their behavior, physiology or other phenotypic traits (non-consumptive effects). Understanding the cues and sensory modalities prey use to detect predators is critical for predicting the strength of non-consumptive effects and the outcome of predator-prey encounters. While predator-associated cues have been well studied in aquatic systems, less is known about how terrestrial prey, particularly insect larvae, detect their predators. We evaluated how Colorado potato beetle, Leptinotarsa decemlineata, larvae perceive predation risk by isolating cues from its stink bug predator, the spined soldier bug, Podisus maculiventris. When exposed to male 'risk' predators that were surgically manipulated so they could hunt but not kill, beetles reduced feeding 29 % compared to controls. Exposure to risk females caused an intermediate response. Beetles ate 24 % less on leaves pre-exposed to predators compared to leaves never exposed to predators, indicating that tactile and visual cues are not required for the prey's response. Volatile odor cues from predators reduced beetle feeding by 10 % overall, although male predators caused a stronger reduction than females. Finally, visual cues from the predator had a weak effect on beetle feeding. Because multiple cues appear to be involved in prey perception of risk, and because male and female predators have differential effects, beetle larvae likely experience tremendous variation in the information about risk from their local environment. [ABSTRACT FROM AUTHOR]

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Herbivory defence chemicals in plants can affect higher trophic levels such as predators and parasitoids, but the impact on pollinators has been overlooked. We show that defensive plant chemicals can damage pollinator fitness when expressed in pollen. Crop lupins ( Lupinus species from Europe and South America) accumulate toxic quinolizidine alkaloids in vegetative tissues, conferring resistance to herbivorous pests such as aphids. We identified the alkaloid lupanine and its derivatives in lupin pollen, and then provided this compound at ecologically-relevant concentrations to queenless microcolonies of bumblebees ( Bombus terrestris) in their pollen to determine how foraging on these crops may impact bee colony health and fitness. Fewer males were produced by microcolonies provided with lupanine-treated pollen and they were significantly smaller than controls. This impact on males was not linked to preference as workers willingly fed lupanine-treated pollen to larvae, even though it was deleterious to colony health. Agricultural systems comprising large monocultures of crops bred for herbivore resistance can expose generalist pollinators to deleterious levels of plant compounds, and the broader environmental impacts of crop resistance must thus be considered. [ABSTRACT FROM AUTHOR]

We investigated the rapid cold hardening (RCH) response in the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). On direct exposure, ≤2 % of adult females survived −10 °C for 2 h. However, when acclimatized first at 5 °C for 1 h, 75 % of females survived. RCH could also be induced by acclimatization at 30 °C for 2 h or anoxia (oxygen-free nitrogen) for 1-2 h. All immature stages showed enhanced survival when acclimatized at 5 °C for 2 h before exposure to −10 °C. Acclimatization at 30 °C induced RCH only in eggs and deutonymphs, and anoxia was effective for eggs, larvae, and deutonymphs. The variability among immature stages may be attributed to the cost associated with the acclimatization treatments. Our findings suggest that RCH may promote the survival of N. californicus during unexpected changes in temperatures, and can be an important feature particularly when this natural enemy is introduced to non-native environments. [ABSTRACT FROM AUTHOR]

Larvae of tortoise beetles are postulated to have fecal shields as the main defensive strategy against predators. Such a device protects beetles both physically and chemically. In order to examine how larvae Chelymorpha reimoseri are protected against predatory ants, which frequently visit extrafloral nectaries in their host plant, the morning glory Ipomoea carnea, we conducted anti-predation bioassays with live 5th instars. In the field, larvae in contact with ants had survival between 40 and 73 %, independently of shield presence. In the laboratory, when exposed to Camponotus crassus, larvae with shields had significantly higher survival (85 %) than those without shields (64 %). In both scenarios, larval survival was significantly higher when compared with palatable Spodoptera frugiperda larvae, as the latter were all consumed. We also observed that when C. reimoseri larvae showed no movement, the ants walked on them without attacking. We hypothesized that if the larval integument has a pattern of cuticular compounds (CCs) similar to that of its host plant, larvae would be rendered chemically camouflaged. In the field and laboratory, the freeze-dried palatable larvae of S. frugiperda treated with CCs of 5th instar C. reimoseri and left on I. carnea leaves were significantly less removed by ants than controls without these compounds. We also found a similarity of approximately 50 % between the CCs in C. reimoseri larvae and I. carnea host leaves. Both findings provide evidence in support of the hypothesis that chemical camouflage plays an important role in larval defense, which is reported for the first time in an ectophagous leaf beetle larva. [ABSTRACT FROM AUTHOR]

The ability to feed on the prey is of great concern for the predatory insects, especially with regard to predatory coccinellid, Cryptolaemus montrouzieri Mulsant, which is mass reared and released into the field in large numbers to control the target pests. The variability associated with feeding potential is partly influenced by the genetic background of the insects and partly due to the environment, but the genetic basis of this trait is not yet fully understood in C. montrouzieri. The aim of this study was to identify the genetic basis of variation and heritability of this quantitative trait in natural populations of C. montrouzieri through isofemale heritability and parent-offspring regression. The regression analyses indicated that there was a significant linear relationship between progeny and their mothers for feeding potential. [ABSTRACT FROM AUTHOR]