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Orchard bees of the genus Osmia Panzer are important pollinators of fruit trees in various regions of the world, with some species commercially available in the United States and Europe. In addition to their pollination services, Osmia lignaria, Osmia cornifrons, Osmia bicornis, and Osmia cornuta have been identified as potential model species for solitary bees in pesticide risk assessment and have been used for the development of new methods to test acute lethal effects via contact and oral routes of exposure. Our goal was to expand the available methodology to characterize the toxicity of pesticides for these solitary bees through a chronic oral test for adult bees. Chronic oral toxicity of pesticides to orchard bees has been reported, but methods differ among research groups. In our study, O. lignaria, O. cornifrons, O. bicornis, and O. cornuta female bees had access to sucrose solution ad libitum in separate, species-specific 10-day tests. Mean body mass, mean daily consumption, and survival differed among the studied bee species. The dose–response test design was validated with dimethoate, a reference toxic compound, and chronic toxicity endpoints were estimated for the 4 Osmia species. The median lethal daily doses normalized by weight for O. lignaria, O. bicornis, O. cornuta, and O. cornifrons were within the same order of magnitude at 0.23, 0.26, 0.49, and 0.61 µg dimethoate/g bee/day, respectively. The methodology described here was aligned as much as possible with the available honey bee and bumble bee standard methods to facilitate the comparison of chronic toxicity profiles among bee species. [ABSTRACT FROM AUTHOR]

Risk assessment for chemicals in the United States relies upon the honey bee (Apis meliffera L. [Hymenoptera: Apidae]) as a surrogate for other bee species. There is uncertainty in extrapolating honey bee toxicity data to bumble bees due to differences in life history strategies, food consumption, and nest structure. Here we evaluated the design of a queenless bumble bee microcolony test that could be considered for generating larval toxicity data. Three microcolony studies were conducted with Bombus impatiens to evaluate the effects of exposure to 1) diflubenzuron in pollen, 2) dimethoate in pollen, and 3) dimethoate in sucrose. Immature drone bee emergence, worker survival, pollen, and sucrose utilization were measured throughout the study duration. For dimethoate, a 10-d chronic adult bumble bee study was also conducted to compare microcolony endpoints to toxicity endpoints on individual adults. Microcolonies exposed to 10 mg diflubenzuron/kg pollen produced fewer adult drones despite no effects on worker survival. Microcolonies treated with dimethoate at ≥3 mg a.i./kg pollen and ≥0.1 mg a.i./kg sucrose solution produced fewer drones. Exposure to dimethoate in the 10-d chronic adult study resulted in direct mortality to the adult workers at ≥0.1 mg a.i./kg diet. Results from the 10-d study suggest direct effects of dimethoate on workers in the microcolony will alter provisioning of diet to the brood, resulting in lower drone production in the microcolony. Our data suggest that the microcolony study is only appropriate to assess brood effects to bumble bees for substances with low toxicity to adults, as demonstrated with diflubenzuron. [ABSTRACT FROM AUTHOR]

To date, regulatory pesticide risk assessments have relied on the honey bee (Apis mellifera L.) (Hymenoptera: Apidae) as a surrogate test species for estimating the risk of pesticide exposure to all bee species. However, honey bees and non- Apis bees may differ in their susceptibility and exposure to pesticides. In 2017, a workshop ('Pesticide Exposure Assessment Paradigm for Non- Apis Bees') was held to assess if honey bee risk assessment frameworks are reflective of non- Apis bee pesticide exposure. In this article, we summarize the workshop discussions on bumble bees (Bombus spp.). We review the life history and foraging behavior of bumble bees and honey bees and discuss how these traits may influence routes and levels of exposure for both taxa. Overall, the major pesticide exposure routes for bumble bees and honey bees are similar; however, bumble bees face additional exposure routes (direct exposure of foraging queens and exposure of larvae and adults to soil residues). Furthermore, bumble bees may receive comparatively higher pesticide doses via contact or oral exposure. We conclude that honey bee pesticide risk assessments may not always be protective of bumble bees, especially queens, in terms of exposure. Data needed to reliably quantify pesticide exposure for bumble bees (e.g. food consumption rates, soil residue levels) are lacking. Addressing these knowledge gaps will be crucial before bumble bee exposure can be incorporated into the pesticide risk assessment process. Because bumble bees exhibit appreciable interspecific variation in colony and behavioral characteristics, data relevant to pesticide exposure should be generated for multiple species. [ABSTRACT FROM AUTHOR]

The honey bee, Apis mellifera L. (Hymenoptera: Apidae), is a model organism for pollinators in risk assessment frameworks globally. The acute toxicity tests with adult honey bees for contact and oral exposure are part of the requirements for pesticide registration and are typically conducted with the active ingredient. A question often asked is if the typical end-use product (TEP) is more toxic than the technical grade active ingredient (TGAI) to honey bees. We explored this question by mining publicly available databases from regulatory agencies worldwide, where testing with the TEP is required. The objective of this study was to determine whether TEPs are comparable in toxicity to the TGAI. The dataset was analyzed via a 3 × 3 contingency table with toxicity categories, as the data cannot be computed for regression analysis. Of the 151 active ingredients with reported endpoints for contact exposure, 28 were classified as either moderately or highly toxic, 123 were classified as practically nontoxic, and 3 were inconclusive. Only two (1.3%) were reclassified from nontoxic to moderately toxic as the TEP. Of the 141 active ingredients with reported endpoints for oral exposure, 23 were classified as moderately or highly toxic, 113 were classified as practically nontoxic, and 5 were inconclusive. Only five (3.6%) were reclassified from nontoxic to moderately toxic as the TEP. Fewer than 5% of the total TEPs evaluated (contact and oral) were shown to be more toxic than the TGAI, suggesting that the risk assessments of TGAIs would be sufficiently protective to pollinators at the screening laboratory level. [ABSTRACT FROM AUTHOR]

ABSTRACT Global declines of bumble bees and other pollinator populations are of concern because of their critical role for crop production and maintenance of wild plant biodiversity. Although the consensus among scientists is that the interaction of many factors, including habitat loss, forage scarcity, diseases, parasites, and pesticides, potentially plays a role in causing these declines, pesticides have received considerable attention and scrutiny. In response, regulatory agencies have introduced more stringent pollinator testing requirements for registration and reregistration of pesticides, to ensure that the risks to pollinators are minimized. In this context, guidelines for testing bumble bees ( Bombus spp.) in regulatory studies are not yet available, and a pressing need exists to develop suitable protocols for routine higher-tier studies with these non- Apis sp., social bees. To meet this need, Bayer CropScience LP, Syngenta Crop Protection LLC US, and Valent USA. Corporation organized a workshop bringing together a group of global experts on bumble bee behavior, ecology, and ecotoxicology to discuss and develop draft protocols for both semi-field (Tier II) and field (Tier III) studies. The workshop was held May 8-9, 2014, at the Bayer Bee Care Center, North Carolina, USA. The participants represented academic, consulting, and industry scientists from Europe, Canada, the United States, and Brazil. The workshop identified a clear protection goal and generated proposals for basic experimental designs, relevant measurements, and endpoints for both semifield (tunnel) and field tests. These initial recommendations are intended to form the basis of discussions to help advance the development of appropriate protocol guidelines. Integr Environ Assess Manag 2016;12:222-229. © 2015 The Authors. Integrated Environmental Assessment and Management Published by SETAC [ABSTRACT FROM AUTHOR]

BACKGROUND Resistance monitoring is an important aspect of insect resistance management and the preservation of insecticide efficacy. The adult vial test ( AVT) is most often used for resistance monitoring for a variety of insects. A potential alternative method is feeding disruption where resistant insects are distinguished from susceptible insects on the basis of their ability to feed on insecticide in nectar containing a colorimetric marker to measure feeding. The advantages of a feeding disruption test ( FDT) for lepidopteran adults might include a more rapid assay than AVT, an assay format easier to prepare, a bioassay applicable to both oral and contact insecticides and the provision of food and water during the course of the test. The objective of the present work was to determine the feasibility of an adult FDT. RESULTS Heliothis virescens moths fed permethrin and spinosad in dyed nectar yielded dose-dependent ingestion, fecal production and mortality data. A permethrin diagnostic dose distinguished pyrethroid-resistant from pyrethroid-susceptible moths, based on fecal production. CONCLUSION Proof of concept was demonstrated for an adult FDT in which resistant moths were distinguished from susceptible moths on the basis of the ability of the insect to feed on insecticide in dyed nectar and produce dyed feces.© 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is among the most valuable agricultural products, but Meloidogyne spp. (root-knot nematode) infestations result in serious crop losses. In tomato, resistance to root-knot nematodes is controlled by the gene Mi-1, but heat stress interferes with Mi-1-associated resistance. Inconsistent results in published field and greenhouse experiments led us to test the effect of short-term midday heat stress on tomato susceptibility to Meloidogyne incognita race 1. Under controlled day/night temperatures of 25°C/21°C, 'Amelia', which was verified as possessing the Mi-1 gene, was deemed resistant (4.1 ± 0.4 galls/plant) and Rutgers, which does not possess the Mi-1 gene, was susceptible (132 ± 9.9 galls/plant) to M. incognita infection. Exposure to a single 3 hr heat spike of 35°C was sufficient to increase the susceptibility of 'Amelia' but did not affect Rutgers. Despite this change in resistance, Mi-1 gene expression was not affected by heat treatment, or nematode infection. The heat-induced breakdown of Mi-1 resistance in 'Amelia' did recover with time regardless of additional heat exposures and M. incognita infection. These findings would aid in the development of management strategies to protect the tomato crop at times of heightened M. incognita susceptibility.