Effects of truck-mounted, ultra low volume mosquito adulticides on honey bees (Apis mellifera) in a suburban field setting

Abstract

Few studies have examined the impact of mosquito adulticides on honey bees under conditions that reflect actual field exposure. Whereas several studies have evaluated the toxicity of mosquito control products on honey bees, most have been laboratory based and have focused solely on acute mortality as a measure of impact. The goal of this study was to determine effects of routine applications of truck-based ultra-low volume (ULV) mosquito adulticides (i.e., Scourge, Duet, and Deltagard) on honey bees in a suburban setting. The mosquito adulticides used in this study were pyrethroids with active ingredients resmethrin (Scourge), prallethrin and sumithrin (Duet), and deltamethrin (Deltagard), in which resmethrin, prallethrin, and sumithrin were synergized with piperonyl butoxide. We measured and compared mortality and detoxification enzyme activities (esterase and glutathione S-transferase) from sentinel beehives within and outside of mosquito control areas. Concurrently, colony health (i.e., number of adult bees, brood quantity and brood quality) was compared throughout the study period. No significant differences were observed in honey bee mortality, colony health or detoxification enzyme activities between treated (five sprayed areas each received one to three insecticide treatment) and control sites (four unsprayed areas that did not receive insecticide treatment) over the seven week study period. However, our laboratory study showed that exposure to resmethrin, the active ingredient in Scourge, caused significant inhibition of esterase activity compared with the control group. Our findings suggest that proper application of truck based insecticides for mosquito control results in little or no exposure and therefore minimal effects on domestic honey bees.

The honey bee, Apis mellifera, cannot be used as a surrogate for the stingless bee Scaptotrigona mexicana to evaluate the effects of pesticide exposure in agricultural landscapes in Southern Mexico

“…Esterase levels reported in our study (Table 2) are low compared to those found by Carvalho et al (2013) demonstrated that organophosphorous insecticides and pyrethroids cause a reduction in activity in these enzymes; P 450 activity, on the other hand, seems to increase in the presence of organophosphorous compounds (Pokhrel et al, 2018;Yao et al, 2018). When comparing our results with those reported for mosquitoes, the concentrations we found are higher than in mosquitoes that have developed resistance to insecticides (8 x 10 − 3 pmol P 450 ) (Dzul et al, 2007).…”

Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

“…This is problematic as successfully developing and implementing a mosquito control strategy goes hand in hand with possessing rigorous and accurate information on the likely distribution of a mosquito species, its host preferences, and when and where they are likely to be host seeking. These factors can vary greatly between mosquito species, or even within species, depending on their location and/or genetic background [ 58 , 59 ]. Without sufficient, high quality information on specific mosquito targets, developing persistent and effective control programs may prove challenging, particularly during outbreaks.…”

Transforming entomology to adapt to global concerns: 2021 student debates

“…Pyrethrins have been used as competent pesticides with less well-known insecticide resistance traits in mosquitoes and other human pests while being safer in indoor domestic settings ( Cuervo-Parra et al 2016 , Smith et al 2016 ). Although considered an uncommon pest management technology, benefits to public health and future broader applications are undeniable as VOCs have proven to control insect vectors and reduce pathogen transmission while being a cost-effective alternative ( Giles et al 2011 , Pokhrel et al 2018 ). Incorporating VOCs into an IPM plan can reduce nontarget effects of classic pest control strategies, while providing enhanced suppression of pests through multiple modes of action.…”