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Honeydew, a sugary excretion produced by sap‐feeding insects, plays a pivotal role in shaping intricate interactions between insects and plants. This review explains the multifaceted aspects of honeydew, beginning with an overview of its production mechanisms and factors influencing its variability across insect species and plant hosts. Exploring its composition, we examine the chemical components and nutritional aspects, highlighting variations based on insect species and plant sources. The impact of honeydew on microbial communities is explored, shedding light on its role in influencing the diversity and abundance of microorganisms. Furthermore, the review investigates how honeydew affects pest behaviour and population dynamics, elucidating plant responses to honeydew deposition. In the realm of biocontrol, we examine the intricate relationships between honeydew and natural enemies, considering potential implications for integrated pest management. Beyond these individual components, the paper discusses the broader ecological consequences of honeydew in ecosystems, emphasizing the interconnected relationships between insects, plants and microorganisms. The review concludes by identifying research gaps and suggesting future directions, recognizing the need for further investigation into areas with potential applications for agriculture and ecology. This review provides a comprehensive synthesis of the current understanding of honeydew's significance in insect–plant interactions, offering insights for both researchers and practitioners in the field. [ABSTRACT FROM AUTHOR]

Herbivore feeding often increases secondary metabolite production in plants. These herbivore‐induced plant proteins might end up in honeydew excreted by phloem‐feeding insects. This is important because honeydew is one of the most abundant and accessible carbohydrate sources for natural enemies in many agroecosystems and these proteins can thus mediate many tri‐trophic interactions. Here, we hypothesized that defensive metabolites induced in the phloem by herbivory accumulate in the honeydew excreted by phloem‐feeding insects and, consequently, affect the fitness of the herbivores' natural enemies that feed on it. We used a tri‐trophic system consisting of citrus plants, the mealybug Planococcus citri and its primary parasitoid Anagyrus vladimiri. First, we assessed A. vladimiri fitness when fed on P. citri honeydew. We then collected honeydew of seven phloem‐feeding insects, including P. citri, and analysed their protein content. Finally, we analysed the effect of superoxide dismutase (SOD), an antioxidant enzyme associated with plant defences that was commonly found in the analysed honeydews, on A. vladimiri fitness. The fitness of A. vladimiri increased when fed on honeydew compared to a sucrose‐based diet, demonstrating that honeydew can contain compounds that benefit natural enemies. Proteomic analyses showed that defence‐related plant proteins were present in honeydew of seven phloem‐feeding insects analysed. Among these, the enzyme SOD was present in honeydew of all of them. Moreover, the levels of SOD were 10‐fold higher in the phloem of plants infested by P. citri than in that of uninfested plants. SOD was also actively excreted in P. citri honeydew, and we proved that it increases the fecundity of the parasitoid A. vladimiri. We conclude that enzymatic proteins induced by herbivory in the phloem and involved in plant defence, accumulate in the honeydew excreted by phloem‐feeding insects and, contrary to the current paradigm, at least some of these can have positive effects on the third trophic level. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Simple Summary: The spotted lanternfly (SLF) is an invasive generalist that is spreading throughout the eastern United States. They feed in large aggregations, but the mechanisms they use to form these aggregations and find each other for mating are poorly understood. Laboratory evidence that they use pheromones is based on volatiles from their bodies and from honeydew excretions, but, due to their broad sensory capabilities, the pheromone components have been difficult to isolate and identify. This is the first evidence gathered in a field study that demonstrates, using naturally collected SLF odors as lures, that volatiles from SLF bodies and honeydew are both required to attract males at mating time and females during oviposition time. Using semiochemicals collected from spotted lanternflies Lycorma delicatula (Hemiptera: Fulgoridae) (SLF) and deployed in the field with circle traps, we demonstrated that SLF responded to SLF pheromones: in particular, this was the case for males while seeking mates and for females while ovipositing. The attractants consisted of SLF body extract emitted from diffuser lures and SLF honeydew on burlap ribbons, collected from heavily infested locations. Traps with attractants were deployed in field sites with very light SLF infestations to avoid competing signals of pre-existing aggregations. The number of SLF equivalents emitted by each diffuser per trapping period was used in a dose–response analysis. Three trees per block received either (1) a control hexane lure and a clean ribbon, (2) a lure containing SLF extract and a clean ribbon, or (3) a lure containing SLF extract and a honeydew-laden ribbon. Ten blocks were sampled three times per week for twelve weeks. We found a significant positive dose–response by males to SLF body extract only in the presence of SLF honeydew, indicating a synergistic effect between honeydew volatiles and body volatiles. This dose–response occurred for five weeks after mating started, after which males no longer responded. Subsequently, females had a significant positive dose–response to SLF extract only in the presence of honeydew when oviposition was their primary activity, continuing for two weeks, suggesting that females may use pheromones to aggregate for oviposition. The extract in the absence of honeydew did not result in a positive dose–response, nor did the hexane control. These findings suggest that SLF respond synergistically to the combination of pheromones present in both SLF honeydew and SLF bodies. Thus, combining key components from both sources may aid the development of semiochemical lures for SLF. [ABSTRACT FROM AUTHOR]

Although blossom and honeydew honeys are produced from different nectar sources, it is very difficult to distinguish them. In this study, physicochemical and biochemical properties were compared to distinguish honeydew and blossom honeys obtained from different botanical sources. The honeys of pine (Pinus spp.) and oak (Quercus, spp.) were used as honeydew honey, and chestnut (Castania sativa L.) and highland honey were used as blossom honey. Turbidity, specific optical rotation (SOR) [α]20, electrical conductivity (EC), CIEL* a*b color parameters, and moisture and pH were assessed as physical parameters. Proline, invertase activity, sugar composition, total phenolic and flavonoid contents, and antioxidant capacity were used as biochemical properties. It was determined that SOR values were the most important parameters in distinguishing honeydew and blossom honeys. Turbidity stands out as a crucial factor in differentiating between pine and oak honeys. Except for chestnut honey, electrical conductivity, CIE color Lab values, and sugar profiles were identified as additional distinguishing factors among the tested honeys. [ABSTRACT FROM AUTHOR]

Honeydew from Hemipteran insects serves as carbohydrate source to beneficial insects but also to various microorganisms. Microbial volatile organic compounds (mVOCs) may play diverse roles in herbivore–microbe–natural enemy interactions. However, the functional significance of mVOCs from aphid honeydew remains largely unclear. In this study, a total of seven cultivable bacteria from Sitobion miscanthi honeydew have been isolated and identified based on 16S rRNA technique, which included Lysinibacillus fusiformis, Erwinia aphidicola, E. tasmaniensis, Acinetobacter bereziniae, Klebsiella quasipneumoniae subsp. Similipneumoniae, Staphylococcus capitis and Bacillus safensis subsp. safensis. One bacterial strain, L. fusiformis MH1, was found to be most attractive to Aphidius gifuensis parasitic wasp in Y-tube olfactometer. Two compounds, namely 1-ethyl-2-methylbenzene and 2-butyl-1-octanol, were emitted from L. fusiformis MH1 and were attractive to A. gifuensis and identified by using coupled gas chromatography–electroantennography and coupled gas chromatography with mass spectrometry. Application of bacterial and mVOCs formulations in crop field resulted in significant aphid abundance decrease associated with higher parasitism rates compared with control. Our results indicated that some microbes in aphid honeydew could manipulate the herbivore–natural enemy interactions and could be developed as a novel alternative for environmentally friendly biological control of aphids. [ABSTRACT FROM AUTHOR]

The invasive mealybug Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) has become a key pest in Mediterranean citrus. This mealybug species excretes honeydew that can be consumed by ants, which may give rise to mutualistic relationships and increase the invasibility of this exotic pest. Here, we studied the interaction between D. aberiae and ants in 16 citrus orchards located in the main citrus-growing area of Spain (Valencia) during two consecutive years. Four native ant species were observed feeding on D. aberiae honeydew, and Lasius grandis Forel (Hymenoptera: Formicidae) represented more than 95% of these ants. Lasius grandis was observed attending D. aberiae throughout the year and in all the orchard sites where the mealybug was present. Mealybug colony size had a positive effect on both relative and absolute ant-attendance by L. grandis, but these interactions varied across seasons. Moreover, we found a positive correlation between L. grandis activity and D. aberiae density in all citrus orchards. Our results suggest that the native ant L. grandis and the invasive pest D. aberiae have established a mutualistic association that promotes the establishment and accelerate the invasion of D. aberiae in Spanish citrus orchards. Further research with the aim of evaluating whether the management of this ant species can improve the control of D. aberiae in citrus would be recommended. [ABSTRACT FROM AUTHOR]

The utilization of controlled greenhouses can be an alternative for melon (Cucumis melo L.) cultivation. Growing melon in greenhouses lowers the risk of pests and infections by diverse pathogens. Low solar irradiation during the rainy season and pollution in the greenhouse roof, may cause shade stress conditions for the plants inside. This study aimed to elucidate the plant and fruit characteristics of nine genotypes of melon grown under shade conditions in a greenhouse and the variability among them. The experiment was conducted in a greenhouse of Cikabayan Experimental Station, IPB University, Bogor, from November 2016 to January 2017. The genetic materials evaluated were nine melon genotypes from the Center for Tropical Fruit Studies at IPB University. A randomized complete block design with three replicates was followed. Shade intensity in the greenhouse was approximately 25%. The results showed that the genotype effect was significant for internode length, petiole length, plant height fruit, flesh thickness, fruit rind thickness, fruit weight, and total soluble solids. Genotype means for fruit weight were small in this experiment (< 300 g), whereas the total soluble solids were moderate to high (8.7-14.3 °Brix). Fruit diameter had a positive and significant correlation with leaf length, leaf width, and fruit length, whereasfruit weight had a positive and significant correlation with fruit diameter and fruit length. [ABSTRACT FROM AUTHOR]

This research was carried out in order to characterize the quality of honey in the area of the city of Bugojno. For this purpose, two (2) types of honey were sampled: honey from honey bee and meadow honey from three (3) different locations in the area of the city of Bugojno: Vrbanja-Kandija, Kula-Bristovi and Poriće-Ždralovići. The pastures of the mentioned areas are separated by approx. 8 km. The honey samples were taken in the period July-August 2022, when the honey was produced. All samples were taken in accordance with the applicable legal regulations. The analysis was done in accordance with EU standards and in accordance with the Rulebook on methods for the control of honey and other bee products (Official Gazette of BiH" 37/09, 2011. The parameters were determined; electrical conductivity, content of mineral substances, free acids, moisture/water, sucrose, invert sugar, hydroxymethylfurfural (HMF). One part of the laboratory tests was done in the laboratory Control H - Mostar, (water, sucrose, invert sugar and HMF), the other part of the laboratory tests was done in the laboratory of the Institute of Natural Sciences, Faculty of Education, University "Džemal Bijedić" in Mostar. According to the obtained results, the following comment can be made: 1. The research results show a significant level of values of the tested parameters, except values determined for hydroxymethylfurfural where the level of HMF presence is low. 2. The content of hydroxymethylfurfural in the examined localities ranged from (0.602 mg/kg) to (2,500 mg/kg). [ABSTRACT FROM AUTHOR]

Ants often interact aggressively for resources (e.g. nest sites and food) with members of their own or another species. In these competitive interactions, dominant ant species exert a strong influence on ant species coexistence and plant‐associated arthropod community structure. However, few studies have experimentally manipulated the relative abundance of dominant ant species on plants, preventing a mechanistic understanding of the effects of ant competitive interactions on ant community structure as well as on their interactions with other insects, particularly mutualistic hemipterans. In this study, we performed a field experiment in a tropical dry forest in Brazil to investigate the effects of two dominant ant species (Camponotus crassus and Cephalotes pusillus) on the structure ant communities and the abundance of the ant‐tended hemipteran Enchenopa brasiliensis in Solanum lycocarpum plants. For this, we identified and quantified all ant species foraging on plants and estimated the number of egg masses, nymphs and adults of the mutualistic hemipteran before and after experimentally removing nests of both two dominant ant species. Our results showed that removal of C. pusillus nests significantly changed ant community structure, whereas removal of C. crassus nests did not. We also found that nest removal of both dominant ant species had significant effects on hemipteran abundance. In particular, plants generally hosted more hemipteran eggs, nymphs and adults after (vs before) nest removal of both dominant ant species. Overall, this study demonstrates that dominant ant species can play a pivotal role in structuring ant communities and the interactions between ants and honeydew‐producing hemipteran insects. [ABSTRACT FROM AUTHOR]

Mutually beneficial associations are widespread in ecological networks. They are typically assembled as multispecies guilds of symbionts that compete for one or more host species. The ant Lasius flavus engages in an intriguing and obligate mutualistic association with a community of aphids that are cultivated on plant roots in its nests. The ant displays a repertoire of amicable behaviors toward the aphids, including their transport. I examined whether L. flavus preferentially carried some of the root aphids. Using a no-choice and a choice experiment, I comparatively analyzed the transport rate of 5 obligate and one loosely associated species back to the ant nest and used the transport rate of the ant larvae as a reference. All associated root aphids were carried back to the nest, but in a clear preferential hierarchy. Geoica utricularia, Forda Formicaria , and Trama rara were rapidly transported, but slower than the own larvae. Tetraneura ulmi and Geoica setulosa were collected at a moderate rate and the loosely associated Aploneura lentisci was slowly retrieved. In contrast, different species of unassociated aphids were not transported and even provoked aggressive behavior in L. flavus. This study revealed that co-occurring symbionts may induce different degrees of host attraction, which ultimately may affect the coexistence and assembly of ant-symbiont communities. [ABSTRACT FROM AUTHOR]

Many ants and hemipterans are bound by a mutualistic relationship (trophobiosis) which represents an ecological keystone: ants receive food (honeydew) providing different kinds of protection. Partner protection against arthropod natural enemies is considered to be frequent and to interfere with biological control strategies of hemipteran pests.We carried out an ant‐exclusion field experiment in a fava bean (Vicia faba) plantation in Italy to monitor the abundance and behaviour of the ants (Plagiolepis pygmaea, Tetramorium semilaeve and the exotic Nylanderia jaegerskioeldi) and their relationship with facultative mutualist (Aphis fabae) and non‐mutualist (Megoura viciae) aphids, the arthropod natural enemies of the aphids, and extrafloral nectaries.Ants concentrated their activity on the attendance of facultative mutualist aphids much more than on the extrafloral nectaries. The ant‐exclusion treatment had no effect on the abundance of M. viciae and on the parasitization rate of A. fabae, while it reduced the abundance of A. fabae, aphid predators, and aphid parasitoids.Our results demonstrate that ant attendance does not imply the protection of aphids from arthropod natural enemies and suggest that the identity of the ant species involved is important for the outcome. As relatively few species have been studied in this regard, extending our knowledge to the role of more ant species is desirable to understand the ecology and evolution of ant‐aphid mutualisms and to refine integrated control strategies of aphid pests. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the characteristic properties of Turkish pine honey, which is an important honeydew honey. The geographical classification of the honey was determined by applying carbon isotope, melissopalynological, and physicochemical analyses to 373 samples collected from 47 regions between 2015 and 2017 under controlled conditions. δ13C protein-δ13Choney, C4%, electrical conductivity, moisture, ash, free acidity, color CIEL* a*b attributes, optical rotation [α]20, proline, diastases activities, and sugars (fructose, glucose, sucrose, and maltose) were used as physicochemical properties. Number of honeydew elements /number of total pollen (NHE/NTP) ratios were studied at melissopalynological analyses. The results showed that all samples exhibited honeydew properties, and that all physicochemical parameters met the criteria set by regulatory standards for honeydew. However, C4% sugar and δ13C protein-δ13C honey values did not meet the regulatory criteria and exhibited quite wide standard deviations. [ABSTRACT FROM AUTHOR]

Simple Summary: Giant pine scale, Marchalina hellenica Gennadius (Hemiptera, Marchalinidae), is a sap sucking insect native to the Eastern Mediterranean Basin. In 2014, giant pine scale was detected for the first time in Victoria, Australia, feeding on a new host, Pinus radiata. We studied the life cycle and feeding activity of giant pine scale in Victoria over 32 months, with the aim of drawing comparisons between exotic and native populations. Australian life stages of this pest emerged during similar months to Greek seasonal equivalents, although the timing of Australian life stages differed between years. Insect density and feeding activity on infested trees differed among locations and between generations. Strong evidence was found in support of density and feeding intensity being explained by climatic conditions. The value of Pinus radiata as a food source for this insect may fluctuate with climate conditions. Our findings aim to inform future management efforts for this scale insect, including surveillance strategies and optimal seasons for release of biocontrol agents. Our findings also suggest that the impact of this pest in Australia may be exacerbated by climate change. Invasive insects pose an increasing risk to global agriculture, environmental stability, and public health. Giant pine scale (GPS), Marchalina hellenica Gennadius (Hemiptera: Marchalinidae), is a phloem feeding scale insect endemic to the Eastern Mediterranean Basin, where it primarily feeds on Pinus halepensis and other Pinaceae. In 2014, GPS was detected in the southeast of Melbourne, Victoria, Australia, infesting the novel host Pinus radiata. An eradication program was unsuccessful, and with this insect now established within the state, containment and management efforts are underway to stop its spread; however, there remains a need to understand the insect's phenology and behaviour in Australia to better inform control efforts. We documented the annual life cycle and seasonal fluctuations in activity of GPS in Australia over a 32 month period at two contrasting field sites. Onset and duration of life stages were comparable to seasons in Mediterranean conspecifics, although the results imply the timing of GPS life stage progression is broadening or accelerating. GPS density was higher in Australia compared to Mediterranean reports, possibly due to the absence of key natural predators, such as the silver fly, Neoleucopis kartliana Tanasijtshuk (Diptera, Chamaemyiidae). Insect density and honeydew production in the Australian GPS population studied varied among locations and between generations. Although insect activity was well explained by climate, conditions recorded inside infested bark fissures often provided the weakest explanation of GPS activity. Our findings suggest that GPS activity is strongly influenced by climate, and this may in part be related to changes in host quality. An improved understanding of how our changing climate is influencing the phenology of phloem feeding insects such as GPS will help with predictions as to where these insects are likely to flourish and assist with management programs for pest species. [ABSTRACT FROM AUTHOR]

We quantified the life table parameters and predation capacity of a generalist predatory mite, Typhlodromus bagdasarjani Wainstein and Arutunjan on five monotypic diets, including Tetranychus urticae Koch (TSSM) eggs in the presence (SW) and absence (SN) of webs, Trialeurodes vaporariorum Westwood (GHWF) eggs (G), honeydew (H), and maize pollen (M) as well as three mixed diets, including SN + M, SN + G, and G + M. Our results showed that the individuals fed on the mixed diets had a considerably shorter developmental time and pre-oviposition period (APOP), higher oviposition days, higher fecundity and population growth rate than those raised on the monotypic diets. Furthermore, we found that the mixed diet of TSSM and GHWF eggs was the most favorable diet, resulted in the highest fecundity and population growth rate, shortest developmental time and APOP. While TSSM eggs alone in the presence of webs and honeydew were the worst diets resulted in the longest developmental time, lower oviposition day, higher fecundity and population growth rate. Our data determined that TSSM has more nutritional benefits than GHWF for T. bagdasarjani. We observed the positive effects of pollen addition to prey on the predatory mite's immature and adult life-history characters; however, it reduced the predation rate. Overall, maize pollen could enhance ecosystem services provided against spider mites and whiteflies by positively impacting the increase of T. bagdasarjani population. This predator may be more effective when two prey species are available than when only one species is present. [ABSTRACT FROM AUTHOR]

Simple Summary: Like many aphids, the sorghum aphid (SA) Melanaphis sorghi produces honeydew, a waste product that can increase parasitoid retention and elicit foraging behaviors on plants. We determined the potential of SA honeydew to retain a common aphid parasitoid, Aphelinus nigritus, to assess the practicality of SA biological control on grain sorghum, Sorghum bicolor. Since SAs also feed on Johnson grass, Sorghum halepense, an alternative plant host, we characterized the composition of honeydew from aphids feeding on either grain sorghum or Johnson grass and evaluated A. nigritus preference for honeydew produced on either plant species. Our study found that A. nigritus often remained on honeydew produced by SAs feeding on both grain sorghum and Johnson grass. However, despite sharing similar sugar, amino acid, and organic acid profiles, honeydew produced on Johnson grass was preferred by A. nigritus over honeydew produced on grain sorghum. Our results suggest that SA honeydew could facilitate A. nigritus parasitoid retention on Johnson grass to lower SA populations before the grain sorghum growing season. How aphid parasitoids of recent invasive species interact with their hosts can affect the feasibility of biological control. In this study, we focus on a recent invasive pest of US grain sorghum, Sorghum bicolor, the sorghum aphid (SA), Melanaphis sorghi. Understanding this pest's ecology in the grain sorghum agroecosystem is critical to develop effective control strategies. As parasitoids often use aphid honeydew as a sugar resource, and honeydew is known to mediate parasitoid–aphid interactions, we investigated the ability of SA honeydew to retain the parasitoid Aphelinus nigritus. Since SAs in the US have multiple plant hosts, and host–plant diet can modulate parasitoid retention (a major component in host foraging), we measured SA honeydew sugar, organic acid, and amino acid profiles, then assessed via retention time A. nigritus preference for honeydew produced on grain sorghum or Johnson grass, Sorghum halepense. Compared to a water control, A. nigritus spent more time on SA honeydew produced on either host plant. Despite similar honeydew profiles from both plant species, A. nigritus preferred honeydew produced on Johnson grass. Our results suggest the potential for SA honeydew to facilitate augmentation strategies aimed at maintaining A. nigritus on Johnson grass to suppress SAs before grain sorghum is planted. [ABSTRACT FROM AUTHOR]

Aphids feed on plant sap from the phloem and xylem and cause the formation of honeydew. This damage is mostly done by wingless aphids, but winged aphids pose more economically important problems such as virus transmission. Cultural, biological, biotechnical and chemical control methods are used in the control of winged and wingless aphids. The flight activity of aphids is difficult to control because a minute or half an hour of feeding is sufficient for a single individual to transmit the disease. In order to benefit from or use integrated pest management strategies (IPM), monitoring the aphid population is the first and most critical step in deciding on the necessary control method. This study was carried out at Çukurova University Plant Protection Experiment Station between October 2009 and October 2011 in order to understand the propagation time of aphids and the targeted sampling method from poultry individuals. A total of 400 trees were planted in the orchard in September 2002 at 5 x 3 m intervals. Different color painted (white, red, blue, yellow and green) water traps (18 x 32 cm) filled with tap water and a small amount of liquid soap were placed between the rows, and each trap was placed on a platform, 120 cm above the ground. Different color painted water traps were used to determine and compare the capture of winged aphids. All captured individuals were diagnosed under the microscope after the preparation was made. After diagnosis, cluster analyzes were evaluated according to color selection and similarity index. In this study, the effect of different colored attractive traps on aphids was investigated. Yellow colored trap showed the strongest attraction for aphids and also for many other pests and beneficial insects groups. Other colored (green, white, red and blue color) traps used in the trial can be recommended in terms of attractiveness and environmentally friendly control for the biotechnical control of aphids. [ABSTRACT FROM AUTHOR]

UV hyperspectral imaging (225 nm–410 nm) was used to identify and quantify the honeydew content of real cotton samples. Honeydew contamination causes losses of millions of dollars annually. This study presents the implementation and application of UV hyperspectral imaging as a non-destructive, high-resolution, and fast imaging modality. For this novel approach, a reference sample set, which consists of sugar and protein solutions that were adapted to honeydew, was set-up. In total, 21 samples with different amounts of added sugars/proteins were measured to calculate multivariate models at each pixel of a hyperspectral image to predict and classify the amount of sugar and honeydew. The principal component analysis models (PCA) enabled a general differentiation between different concentrations of sugar and honeydew. A partial least squares regression (PLS-R) model was built based on the cotton samples soaked in different sugar and protein concentrations. The result showed a reliable performance with R2cv = 0.80 and low RMSECV = 0.01 g for the validation. The PLS-R reference model was able to predict the honeydew content laterally resolved in grams on real cotton samples for each pixel with light, strong, and very strong honeydew contaminations. Therefore, inline UV hyperspectral imaging combined with chemometric models can be an effective tool in the future for the quality control of industrial processing of cotton fibers. [ABSTRACT FROM AUTHOR]

Honeydew is the keystone of many interactions between aphids and their predators, parasitoids, and mutualistic partners. Despite the crucial importance of honeydew in aphid-ant mutualism, very few studies have investigated the potential impacts of climate change on its production and composition. Here, we quantified changes in sugar compounds and the amount of honeydew droplets released by Aphis fabae reared on Vicia faba plants under elevated temperature and/or CO2 conditions. Following the combined elevation of these two abiotic factors, we found a significant increase in the fructose content of A. fabae honeydew, accompanied by nonsignificant trends of increase in total honeydew production and melezitose content. The environmental conditions tested in this study did not significantly impact the other honeydew sugar contents. The observed changes may be related to changes in phloem composition under elevated CO2 conditions as well as to increases in aphid metabolism and sap ingestion under elevated temperatures. Although limited, such changes in aphid honeydew may concurrently reinforce ant attendance and mutualism under elevated temperature and CO2 conditions. Finally, we discuss the enhancing and counteracting effects of climate change on other biological agents (gut microorganisms, predators, and parasitoids) that interact with aphids in a complex multitrophic system. [ABSTRACT FROM AUTHOR]

Bumblebees are opportunistic resource consumers and have been known to visit extrafloral nectaries and harvest aphid and scale honeydew. We report the first observation of bumblebees foraging psyllid honeydew in a tritrophic system in the boreal forest of Yukon Territory, Canada.In this system, a willow (Salix alaxensis) develops bizarrely enlarged petiole bases which act as nursery cavities for large numbers of psyllid immatures of Cacopsylla macleani (Homoptera: Psyllidae), with later instars dispersing over the underside of the leaf.These immatures produced abundant honeydew which was vigorously and persistently foraged by several bumblebees of multiple species (we identified Bombus vancouverensis, Bombus melanopygus and Bombus mckayi). Ants and vespid wasps were also present but in lower numbers.Salix alaxensis and Salix‐feeding psyllids are common throughout arctic and boreal regions, so honeydew production is potentially a supplementary food source for Bombus when floral nectar flows are limited due to low temperatures or drought. [ABSTRACT FROM AUTHOR]

In recent decades, yellowjacket wasps, including Vespula vulgaris, have successfully been established in Patagonia. Additionally, the invasive willow Salix fragilis has also invaded areas next to watercourses, which in turn are typically colonized by the giant willow aphid (GWA, Tuberolagnus salignus), another invasive species. The honeydew exuded by the aphids has been reported to be used as a carbohydrate source by this social wasp. Our aim was to determine whether willows and GWA (invasive complex) on the stream shores promotes yellowjacket population growth. We worked under the hypothesis that GWA provides honeydew (i.e. carbohydrates) to yellowjackets, favouring nest growth and individual fitness. Our results indicate that habitats close (<200 m) to stream margins, where S. fragilis and GWA occur, contain not only a greater abundance of workers but also a higher nest density of V. vulgaris yellowjackets. Even though the nests were similar in size irrespective of the distance to the stream, weight, size and nutritional status of individuals suggest that foraging/nesting in proximity of the invasive complex promotes larger and better nurtured wasps, including reproductive castes, that in the long run could drive population growth and spread of the species in Patagonia. In this context, our study suggests that management of V. vulgaris populations should adopt strategies that encompass a broad approach, especially adopting new strategies designed to contemplate relevant multitrophic interactions between yellowjackets and invasive willows and aphids. [ABSTRACT FROM AUTHOR]

Purpose: The woolly beech aphid thrives on European beech leaves, which has complex direct and indirect impacts on above- and belowground processes. A mechanistic understanding of insect-mediated changes in organic carbon (OC) availability for microbial life and its implications for element cycling is still lacking. This study aims at disentangling aphid-induced effects on phyllosphere and rhizosphere bacterial communities, as well as investigating feedbacks to OC transfer from the canopy to the mineral soil. Methods: Following 2.5 months of infestation, we tracked the fate of OC (13CO2 pulse-labelling) in several compartments of beech sapling – soil mesocosms over 5 days. In ecosystem solutions, water extracts and soil/plant compartments we determined OC and N and solid δ13C. Bacterial community structure (16S rRNA gene targeted amplicon sequencing and quantitative PCR) and metabolite profiles (LC-qTOF-MS) were analysed. Results: We found significantly higher aphid-mediated inputs of OC within throughfall. Honeydew-derived C on infested leaves was inconsequential for total phyllosphere bacterial abundances, but verifiably affected the community structure. In all soil compartments, cold-water extractable OC pools declined significantly by frequent inputs of readily available OC. This pattern might relate to reductions in rhizodepositions and altered microbial processing by accelerated soil C-mineralization. As a result, the abundance of metabolites changed significantly in different ecosystem solutions. Conclusions: Our findings attest that insect infestations induce distinct direct and indirect effects on plant-insect-microbiome interactions leading to marked alterations in C dynamics. This integrated approach improves our understanding on microbial dynamics and biogeochemistry and evaluates the role of insects for ecosystem processes. [ABSTRACT FROM AUTHOR]

Simple Summary: Planthopper outbreaks in rice are associated with excessive fertilizer applications. Public research has focused on developing resistant rice to combat these outbreaks. However, to preserve ecosystem resilience, natural enemy efficacy should be maintained on resistant and susceptible rice. We examined the impact of egg parasitoids on planthoppers (Nilaparvata lugens (Stål) [BPH] and Sogatella furcifera (Horváth) [WBPH]) and a leafhopper (Nephotettix virescens (Distant) [GLH]) in field plots of resistant (IR62) and susceptible (IR64) rice under low and high nitrogen. GLH and WBPH were more abundant in low-nitrogen plots during dry (GLH) and wet (GLH, WBPH) season sampling at an early crop stage. GLH were also more abundant on IR64. Parasitoids killed between 24 and 52% of planthopper eggs during exposures in trap plants. Parasitism by Oligosita and Anagrus wasps was higher on IR64 (BPH eggs) and in high-nitrogen plots (Oligosita spp. on BPH and WBPH eggs; Anagrus spp. on BPH eggs). Parasitism by Anagrus spp. was associated with the presence of honeydew and was highest where honeydew was derived from BPH feeding on IR62; these effects were only observed under high nitrogen. Results suggest that honeydew from IR62 favors parasitoids when plants are most vulnerable (i.e., under high nitrogen), thereby countering nitrogen-induced declines in host resistance. Host plant resistance is the most researched method for the management of planthoppers and leafhoppers in tropical rice. For optimal effects, resistance should be resilient to fertilizer inputs and work in synergy with natural enemies. In field plot experiments, we examined how rice resistance and fertilizer inputs affect mortality of planthopper and leafhopper eggs by hymenopteran parasitoids. We used IR62 as a variety with resistance to Nilaparvata lugens (Stål) [BPH], Sogatella furcifera (Horváth) [WBPH] and Nephotettix virescens (Distant) [GLH], and IR64 as a susceptible control. The herbivores were more abundant during wet season sampling in low-nitrogen plots. During this study, parasitoids killed between 31 and 38% of BPH eggs and 24 and 52% of WBPH eggs during four days of field exposure. Parasitism, mainly due to Oligosita spp., was generally higher in high-nitrogen and IR64 plots. Similar densities of eggs in exposed plants suggest that these trends were mediated by semiochemicals and therefore support the Optimal Defense Hypothesis. Honeydew from BPH on IR62 had more xylem-derived wastes than honeydew on IR64. We applied honeydew from both varieties to sentinel plants. Parasitism by Anagrus spp. was higher on plants of either variety treated with honeydew derived from IR62; however, the effect was only apparent in high-nitrogen plots. Results suggest that Anagrus spp., by responding to honeydew, will counter the nitrogen-induced enhancement of planthopper fitness on resistant rice. [ABSTRACT FROM AUTHOR]

Insect herbivores, such as aphids, are common on plants, yet how they interact with plant microbiomes remains largely unknown. For instance, for the widespread bacterial epiphyte and potential aphid pathogen Pseudomonas syringae , aphids could impact bacterial populations by serving as secondary hosts or by altering the epiphytic habitat through feeding and/or waste secretion. Here, we examined whether the pea aphid, Acyrthosiphon pisum , could influence epiphytic populations of P. syringae. First, we quantified epiphytic growth ability without aphids and virulence to aphids across 21 diverse P. syringae strains. For eight strains that varied in these traits we then assessed the influence of aphid presence on epiphytic bacterial growth. In some cases P. syringae benefited significantly from the presence of aphids, with up to 3.8 times more cell doublings. This benefit was not correlated with strain traits but rather with initial population densities; smaller bacterial populations received relatively more benefit from aphids, and larger populations received less benefit. Honeydew, the sugary waste product of aphids, in the absence of aphids was sufficient to increase P. syringae density on leaves. We conclude that aphid honeydew can sometimes increase P. syringae epiphytic growth but that the bacteria may not benefit from using aphids as hosts. [ABSTRACT FROM AUTHOR]

We report the discovery of the invasive aphid Aphis lugentis for the first time in Australia. This aphid specialises on Compositae, particularly on Senecio species. Aphids were tended by several ant species at a site on Kangaroo Island, South Australia, which is unlikely to be the location of the original introduction. We recommend the investigation of the distribution of A. lugentis in Australia and its impacts on plant hosts including threatened species and associated native ant and aphid community structures. [ABSTRACT FROM AUTHOR]

Aphid cornicles are abdominal appendages that secrete an array of volatile and nonvolatile compounds with diverse ecological functions. The emission of alarm pheromones yields altruistic benefits for clone-mates in the aphid colony, which is essentially a superorganism with a collective fate. Secreted droplets also contain unsaturated triglycerides, fast-drying adhesives that can be lethal when smeared on natural enemies but more often impede their foraging efficiency. The longest cornicles have evolved in aphids that feed in exposed locations and are likely used to scent-mark colony intruders. Reduced cornicles are associated with reliance on alternative defenses, such as the secretion of protective waxes or myrmecophily. Root-feeding and gall-forming lifestyles provide protected feeding sites and are associated with an absence of cornicles. In some eusocial gall-formers, soldier morphs become repositories of cornicle secretion used to defend the gall, either as menopausal apterae that defend dispersing alatae or as sterile first instars that dispatch predators with their stylets and use cornicle secretions as a construction material for gall repair. Collectively, the evidence is consistent with an adaptive radiation of derived cornicle functions molded by the ecological lifestyle of the aphid lineage. [ABSTRACT FROM AUTHOR]

Symbiotic relationships are widespread in nature, but the mechanisms maintaining these relationships remain to be elucidated because symbiosis incurs a maintenance cost to each participant, which lowers its reproductive rate. In host-parasite relationships, parasites are known to manipulate the host's behavior selfishly, and there is an arms race between them. Selfish manipulations also occur in symbiosis, but the effects of selfish manipulations on symbiosis are not fully understood. Here, we show that an ant-associated aphid manipulates attending ants to receive stronger protection. Aphid honeydew regurgitated by ants contains dopamine (DA). The ants showed low aggressiveness before contact with the aphids, but it rose after contact. Administration of DA to the ants increased ant aggressiveness as the concentration increased, while an antagonist of DA inhibited this effect. The other 3 amines showed no effect on aggressiveness. A previous study showed that attending ants selfishly manipulate aphids by increasing the reproductive rate of green morph to obtain high-quality honeydew. These results suggest that mutual selfish manipulation benefits both participants and is likely to strengthen symbiosis. The selfishness of each participant may contribute to sustaining this symbiosis because their selfishness increases their long-term fitness. [ABSTRACT FROM AUTHOR]

The article presents the discussion on Butterfly Community being a threatened flora and fauna community listed in the State of Victoria Flora and Fauna Guarantee Act 1988. Topics include butterflies and moth species intricating ecological interactions forming with host plants and mutualistic ants; and foraging for the honeydew secreted by hemipteran bugs on gum trees and wattles; and providing insightful information about the life history of the small antblue.

The discovery-exploitation tradeoff posits that ant colonies decide between investing in scouts (individual foraging and discovery) or recruits (collective foraging and exploitation) in order to optimize gains. Although this tradeoff has been thoroughly examined through theoretical modelling, research linking model findings to empirical comparative data in ant communities is lacking. We explore the discovery-exploitation tradeoff within an old field ant community in the novel context of a multispecies mutualism with the treehopper Publilia concava. Specifically, we examine the relationship between foraging strategy and ant attentiveness to their treehopper partner, changes in foraging strategy in response to dynamic resources, and how different attendance phenotypes affect partner fecundity. We categorized ants via behavioral assays into "attentive" and "non-attentive" behavioral groups. Foraging strategy differed between ant groups during treehopper oviposition, with "attentive" and "non-attentive" ants favoring collective and individual foraging strategies, respectively. As treehopper nymphs emerged, "non-attentive" Formica subsericea shifted to collective foraging, with a corresponding rapid increase in ant recruitment, while ant recruitment in "attentive" ants remained constant. Treehopper fecundity, however, did not differ when tended by either "attentive" or "non-attentive" ants. We suggest that differences in foraging strategy could be due to residual honeydew left by maternal treehoppers on egg masses, which "attentive" ants exploit. Early recruitment in "attentive" and behaviorally subordinate ants might lead to priority effects, allowing them to persist on host plants and deter invasion from competing ants, which could ultimately lead to species coexistence. [ABSTRACT FROM AUTHOR]

In 2017, damages caused by aphids were observed for the first time on Cedar trees in Bulgaria. In 2020, apterae specimens of Cinara (Cinara) cedri cedri were collected and identified on Cedrus atlantica and C. deodara in seven localities both on young trees in forest nurseries and on old trees in plantations or in green urban systems. The pest appears to be a serious threat to the health status and decorative characteristics of Cedar trees. In case of high population density, the needles are covered with large honeydew secretions and sooty mold. [ABSTRACT FROM AUTHOR]

The effects of drought‐induced changes in plant quality on aphid performance and population growth is well‐studied. The response of aphid behaviour to plant water limitation has received less attention. Water limitation may affect host‐plant colonization by altering the attractiveness of plants. Additionally, plant water limitation may inhibit feeding site establishment and phloem ingestion.Our goal was to examine bird cherry‐oat aphid (Rhopalosiphum padi L.) host selection and feeding behaviour under water limitation. We assessed aphid response to well‐watered, mildly‐stressed, and highly‐stressed wheat (Triticum aestivum L.) by evaluating (i) host‐plant selection through two‐choice assays, (ii) feeding behaviour using the electrical penetration graph technique, and (iii) phloem ingestion by quantifying honeydew production.Aphids were less likely to select highly stressed plants than a mildly stressed or well‐watered alternative. Aphids did not distinguish between mildly stressed and well‐watered plants. Aphid feeding behaviours, including duration of phloem ingestion, were not affected by water availability. However, honeydew production was reduced under both levels of water limitation. These results suggest that the volume of phloem ingested by aphids per unit time declined on stressed plants. The combination of lower colonization and diminished access to food on stressed plants may lead to a reduction in aphid abundance, independent of the direct effects of nutrition on individual aphid performance.This study highlights the potential contribution of herbivore behaviour to documented changes in aphid abundance on stressed plants and underscores the important role of plant water stress intensity in mediating plant‐herbivore interactions. [ABSTRACT FROM AUTHOR]

Plants link interactions between aboveground and belowground organisms. Herbivore-induced changes in plant chemistry are hypothesized to impact entire food webs by changing the strength of trophic cascades. Yet, few studies have explored how belowground herbivores affect the behaviors of generalist predators, nor how such changes may act through diverse changes to the plant metabolome. Using a factorial experiment, we tested whether herbivory by root-knot nematodes (Meloidogyne incognita) affected the aboveground interaction among milkweed plants (Asclepias fascicularis or Asclepias speciosa), oleander aphids (Aphis nerii), and aphid-tending ants (Linepithema humile). We quantified the behaviors of aphid-tending ants, and we measured the effects of herbivore treatments on aphid densities and on phytochemistry. Unexpectedly, ants tended aphids primarily on the leaves of uninfected plants, whereas ants tended aphids primarily at the base of the stem of nematode-infected plants. In nematode-infected plants, aphids excreted more sugar per capita in their ant-attracting honeydew. Additionally, although plant chemistry was species-specific, nematode infection generally decreased the richness of plant secondary metabolites while acting as a protein sink in the roots. Path analysis indicated that the ants' behavioral change was driven in part by indirect effects of nematodes acting through changes in plant chemistry. We conclude that belowground herbivores can affect the behaviors of aboveground generalist ant predators by multiple paths, including changes in phytochemistry, which may affect the attractiveness of aphid honeydew rewards. [ABSTRACT FROM AUTHOR]

The paper describes the determination of riboflavin and thiamine in the best-selling types of 13 raw and 8 commercial monofloral and multifloral honeys originating from Serbia. It was found that there is a difference in average riboflavin and thiamine content between raw and commercial honey, as well as between different honey floral varieties. The results showed that forest, meadow and oregano honey had a significantly higher content of both B vitamins compared to acacia, linden and lavender honey. On the other hand, a very low content of riboflavin and thiamine was found in honeydew honey. Among the commercial products, royal jelly was the richest in thiamine and riboflavin, followed by forest honey. In general, the quality of all of the commercial honey samples regarding these vitamins was lower than that of the raw domestic honeys. [ABSTRACT FROM AUTHOR]

1. Mutualism between ants and honeydew‐excreting hemipterans is ubiquitous in the ecosystem. It is widely accepted that ant tending facilitates the colony growth of hemipterans by protecting them from predators and parasitoids. However, few studies have explored how ant tending helps defend against natural enemies. 2. Ghost ant Tapinoma melanocephalum and the invasive mealybug Phenacoccus solenopsis have a close mutual relationship. Previous studies have shown that ghost ant tending can definitely reduce parasitism and visit frequency of Aenasius bambawalei, the dominant endoparasitoid of P. solenopsis. However, the ghost ant workers seldom attack the parasitoids. It is still unclear how the ghost ant adversely affects parasitoids. This study explored the mechanism underlying the impacts of ants on natural enemies of the mealybugs. 3. Honeydew produced by P. solenopsis was an attractant to A. bambawalei. Parasitoids exhibited less searching activity, shorter longevity and lower parasitism when supplied with less honeydew. Aenasius bambawalei showed significant avoidance of pygidial gland secretions and visual cues of ghost ants. Parasitism in plants treated with 6‐methyl‐5‐hepten‐2‐one, actinidine, and gland extracts was significantly lower than that in plants treated only with solvents (paraffin oil or double‐distilled water). 4. It is concluded that honeydew consumption by ghost ants could negatively influence the performance of parasitoids. The pygidial gland secretions and visual cues of ghost ants also significantly inhibit the parasitism. These results may contribute to a better understanding of the regulation mechanism in ant–hemipteran–enemy interactions. [ABSTRACT FROM AUTHOR]

Honeydew is a sugar-rich food source produced by sap-feeding insects, notably by major pests such as aphids and whiteflies. It is an important alternative food source for the adult stage of various key natural enemies (e.g., parasitoids), but it may be used also as food by agricultural pests. Necremnus tutae is an idiobiont parasitoid, and it is the most abundant larval parasitoid associated with the South American tomato pinworm, Tuta absoluta, in recently invaded European areas. The impact of N. tutae on T. absoluta populations was evaluated under greenhouse conditions with and without the presence of a honeydew producer, the aphid Macrosiphum euphorbiae. In addition, laboratory experiments were performed to evaluate the longevity of N. tutae and T. absoluta adults when fed with water, honey or honeydew produced by the aphid. In the greenhouse, N. tutae effectively reduced T. absoluta population by the end of the experiment, and this independently of the presence of the aphid; still the presence of M. euphorbiae led to delayed and reduced T. absoluta population peak when controlled by the parasitoid (there was a fourfold increase in parasitoid density in presence of aphid). The longevity of both N. tutae and T. absoluta females increased in the presence of honeydew (when compared to water only) under laboratory conditions; it hinted that honeydew could be used by an herbivore as T. absoluta. The interactions between the two phytophagous species showed contrasting effects, and this mostly independently of parasitoid presence. Tuta absoluta had no impact on aphid population dynamics. By contrast, the production of T. absoluta larvae was higher in the first part of the experiment as the adults lived longer (feeding on aphid honeydew) and produced more larvae. In the second part of the experiment, there were fewer T. absoluta larvae in the presence of the aphid, likely owing to resource competition and/or negative plant-mediated indirect interactions. We demonstrated that honeydew producers could impact parasitoid-host population dynamics both through direct and indirect interactions and that potential positive effects of a sugar food source toward a pest can be nullified in the long term by other negative effects occurring simultaneously. [ABSTRACT FROM AUTHOR]

Anagyrus dactylopii (Howard) (Hymenoptera: Encyrtidae) is a solitary koinobiont endoparasitoid of grapevine mealybugs and has been reported to parasitize 70% of mealybug populations naturally. In the present study, we have isolated and identified by employing a 16S rRNA technique, a total of ten cultivable bacteria from the honeydew of two species of grapevine mealybugs, Maconellicoccus hirsutus and Nipaecoccus viridis. In the honeydew of M. hirsutus, seven bacteria were found, which included Micrococcus luteus, Kocuria rosea, Bacillus aquimaris, Exiguobacterium aquaticum, Staphylococcus pasteuri, Bacillus oceanisediminis and Bacillus flexus. From the honeydew of N. viridis, three bacteria, viz. Bacillus firmus, Microbacterium testaceum and Pesudomonas oryzihabitans, could be recovered. Further, we have collected the headspace from 72 h active cultures of these honeydew-associated bacteria by sorption over adsorbent trap made up of 0.2 g porapak using dynamic headspace sampling technique with pull and push system and tested the behavioral responses of mated females of A. dactylopii to these volatiles in a Y-tube olfactometer. The mated females positively responded to volatiles from five bacteria, which included only two bacteria associated with the honeydew of M. hirsutus, i.e., K. rosea, and S. pasteuri and all the three bacteria from honeydew of N. viridis. This indicates an ability of A. dactylopii to exploit cues associated with the mealybug honeydew for host location. The GC–MS analysis of bacterial headspace revealed six volatile organic compounds (VOCs), viz. propanoic acid, 2-methyl-2,2-dimethyl-1-(2-hydroxy-1-methylethyl) propyl ester; tetradecane; dodecane; 10-heptadecen-8-ynoic acid, methyl ester; 10,13-octadecadiynoic acid, methyl ester and limonen-6-ol, pivalate. Interestingly, limonen-6-ol, pivalate has been found as a common constituent of volatiles from all the three bacteria that were isolated from honeydew of N. viridis. The possible exploitation of bacterial VOCs in enhancing populations of A. dactylopii and promoting conservation biological control of mealybugs in grape vineyards is discussed. [ABSTRACT FROM AUTHOR]

Wood ants are common in temperate forests, and while building their nests and foraging for food, they transfer large amounts of organic matter and nutrients. Here, we tested the hypothesis that wood ants generate natural gradients of labile carbon (C) inputs into the soil surrounding their nests. We selected five medium-sized wood ant (Formica aquilonia) nests in a coniferous temperate forest and established sampling points at distances of 4, 30 and 70 m from each nest. Throughfall (honeydew + aboveground vegetation leachates) and litterfall were collected regularly during a vegetative season and were analysed for labile organic C content. In addition, soil from the organic horizon (Oe + Oa), surface mineral horizon (A) and subsoil mineral horizon (B) was collected and analysed for organic matter and nutrient contents. The labile C input in throughfall increased with distance from the nest (it was 1.5-fold greater at 70 m than at 4 m). C input changed during the vegetative season and was highest in June. Litterfall was not affected by the distance from the nest. Organic matter and nutrient contents were unaffected by distance from the nest in surface soil horizons but were significantly higher near the nest (4 m) than 70 m from the nest in the subsoil mineral horizon, suggesting that surface soils are less affected by the labile C inputs than subsoils. Finally, we suggest that the gradients in labile C input surrounding wood ant nests can be used to study the effects of labile C input changes on soil properties. [ABSTRACT FROM AUTHOR]

Pest control in agriculture is mainly based on the application of insecticides, which may impact nontarget beneficial organisms leading to undesirable ecological effects. Neonicotinoids are among the most widely used insecticides. However, they have important negative side effects, especially for pollinators and other beneficial insects feeding on nectar. Here, we identify a more accessible exposure route: Neonicotinoids reach and kill beneficial insects that feed on the most abundant carbohydrate source for insects in agroecosystems, honeydew. Honeydew is the excretion product of phloem-feeding hemipteran insects such as aphids, mealybugs, whiteflies, and psyllids. We allowed parasitic wasps and pollinating hoverflies to feed on honeydew from hemipterans feeding on trees treated with thiamethoxam or imidacloprid, the most commonly used neonicotinoids. LC-MS/MS analyses demonstrated that both neonicotinoids were present in honeydew. Honeydew with thiamethoxam was highly toxic to both species of beneficial insects, and honeydew with imidacloprid was moderately toxic to hoverflies. Collectively, our data provide strong evidence for honeydew as a route of insecticide exposure that may cause acute or chronic deleterious effects on nontarget organisms. This route should be considered in future environmental risk assessments of neonicotinoid applications. [ABSTRACT FROM AUTHOR]

Insects pests such as Mastigimas anjosi Burckhardt (Hemiptera: Calophyidae), native to Brazil, limit the establishment of commercial plantations of the tropical cedar Cedrela fissilis Vell. (Meliaceae), reducing growth and affecting tree shape. Insecticides have been used to suppress M. anjosi outbreaks, but sustainable alternatives should be developed to manage this pest. The objective of this work was to report, for the first time, the predator Atopozelus opsimus Elkins (Hemiptera: Reduviidae) preying on M. anjosi attacking C. fissilis trees in Minas Gerais State, Brazil. Trees of this plant were observed between Apr and May 2018 in Montes Claros, Minas Gerais State, Brazil. Atopozelus opsimus adults preyed on M. anjosi nymphs and adults, and fed on their honeydew. This predator did not eliminate the damage to C. fissilis, which may be related to the temperatures of the region, and which may have affected reproduction and increased its development period. [ABSTRACT FROM AUTHOR]

Nylanderia fulva (Mayr) (Hymenoptera: Formicidae), or tawny crazy ant, is an invasive ant from South America that is spreading in the southern US. Extremely large populations of this ant can inundate urban and natural landscapes, and efficient control methods are lacking. This study was conducted to determine if activity of N. fulva would decline after controlling the hemipteran honeydew-producers they were tending. Potted plants infested with cottony cushion scale (Icerya purchasi Maskell) (Hemiptera: Monophlebidae) were treated with 2 imidacloprid insecticide formulations, and changes in N. fulva survival and foraging behavior were monitored. There were fewer ant trails, lower trailing intensity, less foraging, and less nesting in potted plants treated with either product than in the control pots. The use of low application rates of systemic insecticide to reduce honeydewproducing hemipterans, such as cottony cushion scale, could be an important component of the integrated pest management of N. fulva. [ABSTRACT FROM AUTHOR]

Abstract Rapeseed and honeydew honey were spray dried by dehumidified air, with NUTRIOSE® as a drying carrier, to create a product with prebiotic properties, in line with current "clean label" trend. Because of the low inlet air humidity, drying temperature was decreased (inlet/outlet: 75/50 °C). Such an approach gave the possibility to reduce the amount of added carrier. Thus, honey powders containing 80% of honey solids were produced and characterized. Drying was performed with very high powder recovery (84.4–93.9%), especially in the variants containing 80% of honey solids. Although there were some differences in the physical properties between powders produced by the application of dehumidified air and by the traditional spray drying (but containing the same ratio of honey to carrier), the overall properties were comparable: low water content (below 2.5%) and low water activity (below 0.2), medium or high cohesiveness, high hygroscopicity (above 20%), bed porosity between 50 and 70%. [ABSTRACT FROM AUTHOR]

Abstract Due to the increasing demand and interest of the consumers of bracatinga honeydew honey, it becomes important to know its characteristics in order to guarantee the quality of this dark honey. It is also necessary to investigate possible parameters that easily determine their differentiation from other honeys, thus guaranteeing their authenticity. Therefore, in the present study, the physicochemical characteristics and the reducing/scavenging proprieties of 16 bracatinga (Mimosa scabrella Bentham) honeydew honey samples and 25 blossom honey (different botanical origin) samples from Santa Catarina, Brazil, were investigated. Bracatinga honeydew honeys were defined by its high free acidity, electrical conductivity and reducing/scavenging capacity, and low glucose content.Still, these specific parameters allowed the differentiation between bracatinga honeydew honeys and blossom honeys, from the of principal component analysis, contributing to the differentiation of these honeys. Graphical abstract Unlabelled Image Highlights • Physicochemical characteristics of bracatinga honeydew honey were evaluated. • Only six parameters were sufficient to differentiate bracatinga honeydew honey. • Bracatinga honeydew honey seems to present high acidity as a characteristic. [ABSTRACT FROM AUTHOR]

Highlights • Spiders are efficient predators in agroecosystems against pests. • Different non-prey foods significantly enhanced spiders' fitness. • Spiders actively selected the most beneficial non-prey foods. • Crops can offer alternative foods for spiders. • Agricultural management should promote practices that provide non-prey foods. Abstract Spiders are generalist predators adapted to consume a wide range of prey although their ability to exploit non-prey foods such as pollen, nectar, and honeydew has been referred but less studied. In this work, we investigated the effect of different non-prey food items (Glucose at 0.5 M; aphid honeydew; black scale honeydew; a mixture of glucose 0.5 M, phenylalanine 0.1 mM, proline 0.1 mM, and tryptophan 0.1 mM; honey at 10%, and pollen at 10%) on the survival of immature spiders of two functional groups represented by Haplodrassus rufipes (ground hunters) and Synema globosum (ambushers), and their feeding choices, in laboratory experiments. The overall survival of both species fed on non-prey foods significantly increased compared to individuals fed on water. The black-scale honeydew was the best food for H. rufipes increasing longevity up to 117 days. The highest survival reached by S. globosum was observed when fed on a mixture of glucose 0.5 M and three amino acids. When different non-prey food items were offered together, the exploring rate was significantly higher for H. rufipes than for S. globosum. H. rufipes chose to feed on honey whereas S. globosum chose the mixture treatment. The most chosen food items corresponded with those that provided the highest longevities in both species. Our results suggest that spiders could search, recognize and actively select the most beneficial non-prey food. Habitat management practices such as maintaining weed strips in the crop may provide these valuable supplementary food resources within agroecosystems contributing for biological pest control. [ABSTRACT FROM AUTHOR]

The emergent market for honeydew honey mostly in Europe has prompted increasing requirements by consumers and the honey industry for the characterisation of this type of honey. This work is a contribution to the limited knowledge of honeydew honeys in Spain. Botanical characterisation was performed on 59 honeydew honey samples from professional beekeepers hives distributed within Spain. The quantitative analysis reveals more than 75% of the samples belong to Maurizio Classes II and III, and that, in general, the Spanish Quercus honeydew honeys are characterised by medium high pollen grain content (Pn; mean = 285 197) and honeydew elements (HDEs; mean = 15 850). The analysis also resulted in the identification of spores of several fungal genera (Alternaria, Cladosporium, Drechslera, Geotrichum, Phithomyces, Stemhylium, Torula, Ulocladium and Venturia). All honey samples had a smaller ratio of honeydew elements to pollen grain content (mean HDE/Pn = 0.12), and for the majority of samples (93%) the ratio HDE/Pn was very low (< 0.3), suggesting that this traditional ratio value should not be considered as an indicator of honeydew honeys. The qualitative analysis of the samples showed the presence of 73 taxa belonging to 38 families. Pollen grains of Quercus f., Rubus ulmifloius f., Campanula erinus gr., Capsella f., Cytisus scoparius f., Echium plantagineum gr., Cistus ladanifer f. or Castanea sativa, and, to a lesser extent, those of Crepis f.,Eucalyptus f., Senecio f., Halimium f., Erica australis, Plantago f., Salix triandra gr. and Centaurea calcitrapa gr. are representative of Spanish oak honeydew honeys. [ABSTRACT FROM AUTHOR]

Bird exclusion experiments consistently show that birds exhibit strong top-down control of arthropods, including ants and the honeydew-producing insects (HPIs) that they tend. However, it remains unclear whether the results of these small-scale bird exclosure experiments can be extrapolated to larger spatial scales. In this study, we use a natural bird removal experiment to compare the prevalence of ants and HPIs between Guam, an island whose bird community has been extirpated since the 1980s due to the introduction of the brown tree snake, and two nearby islands (Rota and Saipan) that have more intact bird assemblages. Consistent with smaller-scale bird exclosure experiments, we show that (1) forest trees from Guam are significantly more likely to host HPIs than trees from Saipan and (2) ants are nearly four times as abundant on Guam than on both Saipan and Rota. The prevalence of HPIs varied slightly based on tree species identity, although these effects were not as strong as island-level effects associated with bird loss. Ant community composition differed between Guam and the other two islands. These results corroborate past observational studies showing increased spider densities on Guam and suggest that trophic changes associated with landscape-level bird extirpation may also involve alterations in the abundance of ants and HPIs. This study also provides a clear example of the strong indirect effects that invasive species can have on natural food webs. [ABSTRACT FROM AUTHOR]

The work is focused on the antibacterial effect of four types of blossom honey, one honeydew and two Mānuka honey (MAN100+ and MAN400+) on selected pathogenic microorganisms isolated from cow's milk (Staphylococcus aureus 51 and S. aureus 428), sheep's milk (S. aureus 627), and from the Czech Collection of Microorganisms (Streptococcus uberis CCM 4617, Streptococcus agalactiae CCM 6187, Enterococcus faecalis CCM 4224 and Escherichia coli CCM 4787). The concentrations of honey samples were 20% and 30%. The obtained results showed a 100% inhibitory effect of MAN400+ on all tested bacterial strains even at a concentration of 20% and also a comparable inhibitory effect of Mānuka honey with Czech honeydew. The results indicate that honey had an inhibitory effect against the tested bacterial species which may cause mastitis. [ABSTRACT FROM AUTHOR]

Abstract The increasing demand for honeydew honeys by consumers has raised concerns regarding the authenticity of this product. Therefore, the aim of this study was to develop a classification model (Classification and Regression Tree) to differentiate Mimosa scabrella Bentham (bracatinga) honeydew honeys from blossom honeys. The model was then used to verify the authenticity of commercial samples of honeydew honey. A total of 67 honey samples were analyzed, including 13 bracatinga honeydew honeys, 20 blossom honeys, seven commercial bracatinga honeydew honeys and 27 bracatinga honeydew honeys blended (adulterated) with blossom honey (5, 15 and 25% of blossom honey). In the classification model developed clear parameters were established that characterized each group of honey and with its application all honeydew and blossom samples were correctly classified. Only two samples of adulterated honeydew honey were misclassified. Therefore, the proposed classification model shows promising perspectives for its application, aimed at improving authenticity verification and fraud detection with regard to bracatinga honeydew honeys. Highlights • Honeydew honeys were distinguished from blossom honeys. • All honeydew honeys were correctly differentiated. • Four samples of commercial honeydew honey were adulterated. • Minerals can be used to verify honey authenticity. • This classification method can be used for honey authenticity verification. [ABSTRACT FROM AUTHOR]

A modified method for enzymatically measuring concentrations of glucose, fructose and trehalose in parasitoid wasps is described and evaluated. The method has high specificity, gives results comparable to high performance liquid chromatography (HPLC), and shows good correlations with HPLC. The enzymatic method is quicker and less expensive than HPLC, and is safer, faster and more sensitive than another commonly used insect sugar determination method, the anthrone test. The method has potential to measure additional sugars, and details for measuring sucrose are provided as Supplementary material . We also investigate if endogenous enzymes can retain activity in insects preserved in ethanol, thus potentially skewing insect sugar measurements. The results show that the enzyme trehalase, which converts the insect haemolymph sugar trehalose to glucose, can remain active in insect specimens that are stored whole in ethanol. Thus, sugar measurements from insects preserved in this way have potential for bias towards low trehalose and high glucose. In contrast, the activity of endogenous trehalase in insects that are either frozen at −20 °C, or crushed in ethanol is either much reduced or eliminated. If, prior to sugar analysis, insects are to be stored in ethanol at temperatures above −20 °C, then we recommend they be crushed. [ABSTRACT FROM AUTHOR]

Abstract: Animal mutualisms, which involve beneficial interactions between individuals of different species, are common in nature. Insect–insect mutualism, for example, is widely regarded as a keystone ecological interaction. Some mutualisms are anticipated to be modified by climate change, but the focus has largely been on plant–microbe and plant–animal mutualisms rather than those between animals. Ant–aphid mutualisms, whereby ants tend aphids to harvest their honeydew excretions and, in return, provide protection for the aphids, are widespread. The mutualism is heavily influenced by the quality and quantity of honeydew produced by aphids, which is directly affected by host plant quality. As predicted increases in concentrations of atmospheric carbon dioxide (eCO2) are widely reported to affect plant nutritional chemistry, this may also alter honeydew quality and hence the nature of ant–aphid mutualisms. Using glasshouse chambers and field‐based open‐top chambers, we determined the effect of eCO2 on the growth and nutritional quality (foliar amino acids) of lucerne (Medicago sativa). We determined how cowpea aphid (Aphis craccivora) populations and honeydew production were impacted when feeding on such plants and how this affected the tending behaviour of ants (Iridomyrmex sp.). eCO2 stimulated plant growth but decreased concentrations of foliar amino acids by 29% and 14% on aphid‐infested plants and aphid‐free plants, respectively. Despite the deterioration in host plant quality under eCO2, aphids maintained performance and populations were unchanged by eCO2. Aphids induced higher concentrations of amino acids (glutamine, asparagine, glutamic acid and aspartic acid) important for endosymbiont‐mediated synthesis of essential amino acids. Aphids feeding under eCO2 also produced over three times more honeydew than aphids feeding under ambient CO2, suggesting they were imbibing more phloem sap at eCO2. The frequency of ant tending of aphids more than doubled in response to eCO2. To our knowledge, this is the first study to demonstrate the effects of atmospheric change on an ant–aphid mutualism. In particular, these results highlight how impending changes to concentrations of atmospheric CO2 may alter mutualistic behaviour between animals. These could include positive impacts, as reported here, shifts from mutualism to antagonism, partner switches and mutualism abandonment. [ABSTRACT FROM AUTHOR]