A new ingestion bioassay protocol for assessing pesticide toxicity to the adult Japanese orchard bee (Osmia cornifrons)

Abstract

Adopting an Integrated Pest and Pollinator Management strategy requires an evaluation of pesticide risk for pollinator species. For non-Apid species, however, the standardized ingestion assays are difficult to implement. This hinders the consideration of non-Apid species in farm management strategies and government regulatory processes. We describe a new method for a mason bee, Osmia cornifrons, which is an important pollinator of apples and other fruit crops. Our approach overcomes high control mortality seen in other bioassay protocols and expands testing to include males as well as females. The new pesticide toxicity assessment protocol showed that (1) a group feeding method is optimum even though there is no trophallaxis, (2) males had better tolerance to pesticides although they are smaller, and (3) pesticides can cause additional mortality after the standard 48 h assessment time specified by European Food Safety Authority and U.S. Environmental Protection Agency.

Toxicity of Formulated Systemic Insecticides Used in Apple Orchard Pest Management Programs to the Honey Bee (Apis mellifera (L.))

“…However, all bees were sustained on sucrose solution long after the experiment was over, and only the untreated control bees survived beyond 7 days, indicating delayed mortality in treated bees. The poisoning symptoms observed mirrored those already reported in similar studies [59,69]. Sublethal effects such as staggering, partial paralysis, abdomen tucking, and twitching were observed to some degree in all treated bees during the feeding period, but most often in those treated with thiamethoxam and sulfoxaflor.…”

“…Quantal response regressions were estimated assuming the normal distribution (i.e., probit model) with the computer program POLOPlus 2.0 (LeOra Software [58]) as described by Robertson et al [56]. The median lethal concentration (LC 50 and LC 90 ) values with 95% confidence intervals were also calculated using POLOPlus 2.0, and the median lethal dose (LD 50 ) values were calculated based on the procedure described in Phan et al [59].…”

Method for maintaining adult solitary bee Centris analis under laboratory conditions

“…The survival of C. analis under laboratory conditions was improved by the presence of a wood block and an artificial fabric flower, both of which served as a support surface for feeding and resting, and by the absence of photoperiod. In other studies with solitary bees, tests under laboratory conditions are frequently conducted with photoperiod (Huntzinger et al, 2008;Phan et al, 2020;Sgolastra et al, 2018). This is the first study that shows reduced bee survival during the acclimatization stage caused by phototactic behaviour under laboratory conditions.…”

“…Recent studies indicate that the risk assessment protocol used at pesticide regulation in European countries, the United States and Brazil is insufficient to protect all bees (Fisher, 2021; Franklin & Raine, 2019; Schmolke et al., 2021; Sgolastra et al., 2020). One of the suggestions to improve the risk assessment is to include more bee species in the scenario simulations (Phan et al., 2020). While other countries proposed the use of Osmia species to represent solitary bees in risk assessment (Eeraerts et al., 2020; EFSA, 2013), in Brazil, we do not have toxicology protocols for solitary bees.…”

“…species in the scenario simulations (Phan et al, 2020). While other countries proposed the use of Osmia species to represent solitary bees in risk assessment (Eeraerts et al, 2020;EFSA, 2013), in Brazil, we do not have toxicology protocols for solitary bees.…”