The topical toxicities of five commercial grade pesticides commonly sprayed in apple orchards were estimated on adult worker honey bees, Apis mellifera (L.) (Hymenoptera: Apidae) and Japanese orchard ...bees, Osmia cornifrons (Radoszkowski) (Hymenoptera: Megachilidae). The pesticides were acetamiprid (Assail 30SG), λ-cyhalothrin (Warrior II), dimethoate (Dimethoate 4EC), phosmet (Imidan 70W), and imidacloprid (Provado 1.6F). At least 5 doses of each chemical, diluted in distilled water, were applied to freshly-eclosed adult bees. Mortality was assessed after 48 hr. Dose-mortality regressions were analyzed by probit analysis to test the hypotheses of parallelism and equality by likelihood ratio tests. For A. mellifera , the decreasing order of toxicity at LD 50 was imidacloprid, λ-cyhalothrin, dimethoate, phosmet, and acetamiprid. For O. cornifrons , the decreasing order of toxicity at LD 50 was dimethoate, λ-cyhalothrin, imidacloprid, acetamiprid, and phosmet. Interaction of imidacloprid or acetamiprid with the fungicide fenbuconazole (Indar 2F) was also tested in a 1∶1 proportion for each species. Estimates of response parameters for each mixture component applied to each species were compared with dose-response data for each mixture in statistical tests of the hypothesis of independent joint action. For each mixture, the interaction of fenbuconazole (a material non-toxic to both species) was significant and positive along the entire line for the pesticide. Our results clearly show that responses of A. mellifera cannot be extrapolated to responses of O.cornifrons , and that synergism of neonicotinoid insecticides and fungicides occurs using formulated product in mixtures as they are commonly applied in apple orchards.
Pollinators provide a crucial ecosystem service by pollinating commercially cultivated crops, but they are frequently exposed to various agricultural chemicals used for pest management. In this ...study, we assessed the potential exposure of pollinators to various systemic insecticides and a fungicide used in apple orchards. Residue levels were determined for the whole flower as well as pollen and nectar separately for pre-bloom applications of acetamiprid, imidacloprid, sulfoxaflor, thiacloprid, thiamethoxam, and myclobutanil. Very low pesticide residue levels (2–70 parts per billion, ppb) were found in the whole flower, pollen and nectar samples compared with pesticide concentrations of 60–200 parts per million (ppm) in applied foliarly only 5 days earlier. Insecticide residues from nectar and pollen samples were below the USA EPA classification of No Observable Effect Limit (NOEL) for acute toxicity to honey bees, suggesting that a single foraging visit to flowers may not cause toxicity to bees. However, cumulative acute exposure from multiple flower visits could potentially be harmful to bees, and needs to be studied further. We also examined apple flowers for residues of several systemic insecticides that were applied for brown marmorated stink bug control late in the fall of the previous season. None of the fall sprays that contained premixed insecticide active ingredients (viz., thiamethoxam + lambda-cyhalothrin, and imidacloprid + beta-cyfluthrin), including multiple applications of individual active ingredients (viz., dinotefuran, clothianidin, and sulfoxaflor), persisted until the following spring. Based on these findings, fall applications of insecticides used for controlling invasive pests such as the brown marmorated stink bug (Halyomorpha halys) and the spotted lanternfly (Lycorma delicatula) could be considered safe to pollinator species foraging in apple orchards during the spring bloom the following season.
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•Low pesticide residues were found in apple pollen and nectar from pre-bloom foliar sprays.•Residue levels suggest that a single visit to flowers may not cause toxicity to bees.•No residues were detected in spring from the previous year fall sprays of insecticides.•Fall sprays could be considered safe to pollinators foraging in the following spring.
Pollinator nutritional ecology provides insights into plant-pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient ...intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous research revealed that pollen protein to lipid ratios (P:L) shape bumble bee foraging preferences among pollen host-plant species, and these preferred ratios link to bumble bee colony health and fitness. Yet, we are still in the early stages of integrating data on P:L ratios across plant and bee species. Here, using a standard laboratory protocol, we present over 80 plant species' protein and lipid concentrations and P:L values, and we evaluate the P:L ratios of pollen collected by three bee species. We discuss the general phylogenetic, phenotypic, behavioral, and ecological trends observed in these P:L ratios that may drive plant-pollinator interactions; we also present future research questions to further strengthen the field of pollination nutritional ecology. This dataset provides a foundation for researchers studying the nutritional drivers of plant-pollinator interactions as well as for stakeholders developing planting schemes to best support pollinators.
Insect pollinators such as bees and syrphid flies play a crucial role in pollinating many food crops, and their diversity and abundance may be influenced by pesticide application patterns. Over three ...years, we assessed the ecotoxicological impacts on the diversity and abundance of bees and syrphid flies between reduced-risk pesticide programs and standard, conventional pesticide programs in paired plots at six spatially distinct commercial apple orchards. In particular, we quantified pesticide inputs, environmental impact, and community response of bees and syrphids to these pesticide programs. Relative environmental impacts of reduced-risk versus conventional pesticide programs were calculated using Environmental Impact Quotient analysis, while ecological impacts were characterized by assessing the abundance, richness, and species assemblages of bees and syrphids. Adopting a reduced-risk pesticide program for apple pest management reduced the use (in terms of kg a.i./ha) of organophosphate and pyrethroid insecticides by approximately 97.6% and 100% respectively, but increased the use of neonicotinoid pesticides (acetamiprid, imidacloprid, thiacloprid) by 40.4% compared to the orchards under standard conventional pesticide program. Regardless of pesticide inputs, abundance, richness and species assemblages of bees and syrphids did not differ between reduced-risk and conventional pest management programs. However, the environmental impact of pesticide inputs was reduced by 89.8% in reduced-risk pesticide program. These findings suggest that the implementation of reduced-risk pesticide program may reduce pesticide environmental impact, in addition to being safer to farm workers, without adversely affecting the robust community composition of bees and syrphids in commercial apple orchards in the mid-Atlantic region.
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•Community-level ecotoxicological impacts of reduced-risk and conventional pest management programs in apple orchards were assessed.•Pesticide inputs and response of bees and syrphid flies were quantified.•Community response of bees and syrphid flies did not differ between pesticide programs.•Reduced-risk pesticide program reduced the use of organophosphates and pyrethroids.•Environmental impact of pesticide inputs was greatly reduced in reduced-risk program.
The European honey bee, Apis mellifera, serves as the principle managed pollinator species globally. In recent decades, honey bee populations have been facing serious health threats from combined ...biotic and abiotic stressors, including diseases, limited nutrition, and agrochemical exposure. Understanding the molecular mechanisms underlying xenobiotic adaptation of A. mellifera is critical, considering its extensive exposure to phytochemicals and agrochemicals present in the environment. In this study, we conducted a comprehensive structural and functional characterization of AmGSTD1, a delta class glutathione S-transferase (GST), to unravel its roles in agrochemical detoxification and antioxidative stress responses. We determined the 3-dimensional (3D) structure of a honey bee GST using protein crystallography for the first time, providing new insights into its molecular structure. Our investigations revealed that AmGSTD1 metabolizes model substrates, including 1-chloro-2,4-dinitrobenzene (CDNB), p-nitrophenyl acetate (PNA), phenylethyl isothiocyanate (PEITC), propyl isothiocyanate (PITC), and the oxidation byproduct 4-hydroxynonenal (HNE). Moreover, we discovered that AmGSTD1 exhibits binding affinity with the fluorophore 8-Anilinonaphthalene-1-sulfonic acid (ANS), which can be inhibited with various herbicides, fungicides, insecticides, and their metabolites. These findings highlight the potential contribution of AmGSTD1 in safeguarding honey bee health against various agrochemicals, while also mitigating oxidative stress resulting from exposure to these substances.
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•The three-dimensional structure of AmGSTD1 was solved by X-ray crystallography.•G-site S34A and H-site F142A mutants exhibited the largest changes in kinetics.•Herbicides, fungicides, insecticides, and metabolites hindered AmGSTD1-ANS binding.•AmGSTD1 was highly expressed in the Malpighian tubules of both nurse and forager bees.
During bloom of spring orchard crops, bees are the primary providers of pollination service. Monitoring these insects for research projects is often done by timed observations or by direct aerial ...netting, but there has been increasing interest in blue vane traps as an efficient passive approach to collecting bees. Over multiple spring seasons in Michigan and Pennsylvania, orchards were monitored for wild bees using timed netting from crop flowers and blue vane traps. This revealed a distinctly different community of wild bees captured using the two methods, suggesting that blue vane traps can complement but cannot replace direct aerial netting. The bee community in blue vane traps was generally composed of nonpollinating species, which can be of interest for broader biodiversity studies. In particular, blue vane traps caught Eucera atriventris (Smith), Eucera hamata (Bradley), Bombus fervidus (F.), and Agapostemon virescens (F.) that were never collected from the orchard crop flowers during the study period. Captures of bee species in nets was generally stable across the 3 yr, whereas we observed significant declines in the abundance of Lasioglossum pilosum (Smith) and Eucera spp. trapped using blue vane traps during the project, suggesting local overtrapping of reproductive individuals. We conclude that blue vane traps are a useful tool for expanding insights into bee communities within orchard crop systems, but they should be used with great caution to avoid local extirpation of these important insects.
•Pesticide use in crops can be harmful to pollinators, but each pesticide type differentially affects various pollinator species including honey bees, bumble bees and solitary bees.
In this chapter ...we argue that while pesticides can be harmful to pollinators, when they are used in an integrated pest and pollinator management (IPPM) context, both pest management and pollinator protection may be achieved. Our growing knowledge of the impacts of pesticides on honey bees as well as bumble bees and solitary bees allows us to use the latitude we have in pest management including non-pesticidal pest management practices, changing pesticide types and incorporating other, less susceptible pollinator species into commercial practice. Pollinator health should be a central component of integrated pest management research, education and extension to produce viable IPPM approaches.
Bees are important pollinators of numerous crops, and monitoring their abundance and diversity in commercial agricultural ecosystems is of increasing importance due to pollinator declines. In ...season-long field studies conducted in Pennsylvania during 2011–2013, we evaluated five different bee monitoring passive traps—three pan traps (blue, yellow, and white) and two vane traps (blue and yellow)—for their effectiveness and utility for monitoring bees in commercial apple orchards. Traps were placed prebloom and were monitored weekly until the end of crop season (mid-October). We recorded 14,770 bees comprising 118 species, 27 genera, and five families. The most abundant species were Augochlora pura (Say) (34.4% of total), Ceratina calcarata Robertson (15.5%), Bombus vagans Smith (7.8%), Bombus impatiens Cresson (6.4%), and Apis mellifera L. (4.3%). Bee abundance was highly variable among trap types across the three years and during the bloom and postbloom period. Blue vane traps were found to be the most effective trap type, with significantly higher rates of per-sample species accumulation than all other traps. Species richness estimates were highest for the blue vane and blue pan traps. This study reveals the utility and effectiveness of various traps for studying abundance and diversity of pollinator bees in commercially managed apple orchards. It also provides baseline information about the bee community found during the bloom and postbloom periods in Pennsylvania apple orchards that can be used to measure changes in bee community structure and abundance due to conservation efforts, such as reduced risk IPM programs, habitat management, and augmentation.
Natural habitats, comprised of various flowering plant species, provide food and nesting resources for pollinator species and other beneficial arthropods. Loss of such habitats in agricultural ...regions and in other human-modified landscapes could be a factor in recent bee declines. Artificially established floral plantings may offset these losses. A multi-year, season-long field study was conducted to examine how wildflower plantings near commercial apple orchards influenced bee communities. We examined bee abundance, species richness, diversity, and species assemblages in both the floral plantings and adjoining apple orchards. We also examined bee community subsets, such as known tree fruit pollinators, rare pollinator species, and bees collected during apple bloom. During this study, a total of 138 species of bees were collected, which included 100 species in the floral plantings and 116 species in the apple orchards. Abundance of rare bee species was not significantly different between apple orchards and the floral plantings. During apple bloom, the known tree fruit pollinators were more frequently captured in the orchards than the floral plantings. However, after apple bloom, the abundance of known tree fruit pollinating bees increased significantly in the floral plantings, indicating potential for floral plantings to provide additional food and nesting resources when apple flowers are not available.
(Koch) (Acari: Tetranychidae), commonly known as European red mite, is a polyphagous pest of various tree and small fruit crops, including apples. A field study was conducted to evaluate different ...pesticide options available for the management of
, and their impact on the population of non-target predatory mite species complex consisting of
,
, and
in apple orchards. Pesticides were applied using a commercial airblast sprayer at the 3-5 mite/leaf recommended economic Integrated Pest Management (IPM) threshold or prophylactically in the spring ignoring IPM practices such as monitoring, reliance on biological control and economic thresholds. Effects on the motile and egg stages of
were evaluated as were effects on the populations of predatory mites through frequent leaf counts during the season. We also recorded the subsequent overwintering eggs of
from each pesticide treatment. The two prophylactic treatments containing a mixture of zeta-cypermethrin + avermectin B1 + 1% horticultural oil and abamectin + 1% horticultural oil provided effective control of
population throughout the season without reducing predatory mite populations. In contrast, eight treatments applied at the recommended economic threshold of 3-5 mites/leaf were not effective in suppressing
populations and most reduced predatory mites. Etoxazole had significantly higher number of overwintering
eggs compared to all other treatments.
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