The Effects of the Insect Growth Regulators Methoxyfenozide and Pyriproxyfen and the Acaricide Bifenazate on Honey Bee (Hymenoptera: Apidae) Forager Survival

Abstract

The honey bee (Apis mellifera L. (Hymenoptera: Apidae)) contributes an essential role in the U.S. economy by pollinating major agricultural crops including almond, which depends entirely on honey bee pollination for successful nut set. Almond orchards are often treated with pesticides to control a variety of pests and pathogens, particularly during bloom. While the effects to honey bee health of some insecticides, particularly neonicotinoids, have received attention recently, the impact of other types of insecticides on honey bee health is less clear. In this study, we examined the effects to honey bee forager survival of three non-neonicotinoid pesticides widely used during the 2014 California almond bloom. We collected foragers from a local apiary and exposed them to three pesticides at the label dose, or at doses ranging from 0.5 to 3 times the label dose rate. The selected pesticides included the insect growth regulators methoxyfenozide and pyriproxyfen, and the acaricide bifenazate. We simulated field exposure of honey bees to these pesticides during aerial application in almond orchards by using a wind tunnel and atomizer set up with a wind speed of 2.9 m/s. Experimental groups consisting of 30-40 foragers each were exposed to either untreated controls or pesticide-laden treatments and were monitored every 24 hr over a 10-d period. Our results revealed a significant negative effect of all pesticides tested on forager survival. Therefore, we suggest increased caution in the application of these pesticides in almond orchards or any agricultural crop during bloom to avoid colony health problems.

Neurotoxicity and mode of action of fluralaner on honeybee Apis mellifera L.

“…It inhibits the mitochondrial complex III in the spider mite T. urticae, and exhibits synergistic action of GABA response in Tu RDL GABAR . Recently, Fisher II et al (2018) reported that bifenazate could cause significantly negative effects on honeybee forager survival . Hence, the effect of bifenazate to Am RDL homopentamers was investigated in the current study.…”

Landscape factors influencing honey bee colony behavior in Southern California commercial apiaries

“…Some compounds, such as methoxyfenozide and flupyradifurone, were at high, albeit sublethal levels 29 . The IGRs methoxyfenozide and pyriproxyfen have been shown to reduce forager survival 4 . By October fewer pesticides were being detected overall, but the hives in MT landscapes were clearly being exposed www.nature.com/scientificreports www.nature.com/scientificreports/ to high levels of fungicides (chlorothalonil), herbicides (chlorthal-dimethyl and prodiamine) and IGRs (methoxyfenozide).…”

Effects of Pesticides and Adjuvants on the Honey Bee, Apis mellifera: An Updated Bibliographic Review

“…In addition, exposure to fenoxycarb affects the ability of colonies to overwinter, which reduces winter survival [58]. The juvenile hormone mimic, pyriproxyfen, affects synthesis and accumulation of vitellogenin (protein in hemolymph from which egg yolk is derived) in young worker bees [68] and negatively affects survival of honey bee foragers [69].…”

“…Ecdysone receptor antagonists/agonists are insect growth regulators that disrupt molting by inhibiting metabolism of the molting hormone, ecdysone, or they bind to ecdysone receptors, resulting in premature molting of larvae or nymphs, and eventually death [54,60,70,71]. Methoxyfenozide does not exhibit any harmful effects on honey bee larvae or adults [9] although Fisher et al [69] reported that methoxyfenozide negatively affected the survival of honey bee foragers. In general, tebufenozide has been shown to exhibit no direct or indirect harmful effects to honey bee colonies or queen development [58]; however, Abramson et al [56] found that tebufenozide negatively affected the learning behavior of honey bee adults.…”