Semi–field Evaluation of Ultra-Low Volume (Ulv) Ground Spray of Aqualuer® 20-20 Against Caged Aedes Albopictus and Non-Target Honey Bee, Apis Mellifera

Abstract

Application of permethrin products by ultra-low volume (ULV) spraying against the container-inhabiting mosquito Aedes albopictus (Skuse) has been used for many years, but the impact of the insecticides on domesticated honey bees, Apis mellifera (Linnaeus) is still lacking. The present study was carried out to evaluate the impact of the permethrin product, Aqualuer® 20-20 (active ingredient: 20.6% permethrin+20.6% Piperonyl butoxide) ULV sprays on caged Ae. albopictus and A. mellifera in open semi-field conditions with cages spaced at 3 m, 22.8 m, and 45.7 m downwind of the spray-truck path. The results indicated that ULV spray of Aqualuer 20-20 is highly effective against Ae. albopictus achieving 94% mortality at 22.8 m and 82% mortality up to 45.7 m downwind distance. The highest mortality of A. mellifera was only 72% at 3 m downwind distance, but the spray killed 42% of the exposed bees up to 45.7 m down the spray path. This semi-field study conducted during the day time indicates the high effectiveness of the ULV spray of permethrin against Ae. albopictus and its comparatively low impact on the direct exposed non-target honey bee, A. mellifera. Further studies designed to be conducted in the natural environment during its real-time operations following label instructions of the insecticide will help establish spraying guidelines to minimize any unfavorable impact on domesticated A. mellifera while having expected mortality effects on Ae. albopictus.

Adult Mosquito and Butterfly Exposure to Permethrin and Relative Risk Following ULV Sprays from a Truck-Mounted Sprayer

“…Permethrin toxicity to mosquitoes has been well investigated given its use for the control of adult mosquitoes (Zhang et al 2015 ; Whiten and Peterson 2016 ; Gong et al 2017 ; Sanchez-Arroyo et al 2021 ; 2022 ), but the concentrations affecting the mosquitoes are often reported as nominal. Assumptions about exposures based on dose solution concentrations or possible unintended errors in toxicant delivery to an organism the size of an adult mosquito could lead to inaccuracies in the reported effect concentrations.…”

Insecticide Toxicity to Honey Bees: Lessons Learned From Studies by the University of Florida Urban Entomology Laboratory

“…Formulated insecticides were used to treat paper or other surfaces to simulate insecticide exposure when they land on treated foliage or other surfaces in the field and LC 50 s (µg/cm 2 ) of mosquito residual adulticides were determined for both species of mosquitoes and the honey bee. In semi-field studies (Sanchez-Arroyo et al 2022a, Sanchez-Arroyo et al 2022b, the differential toxicity of insecticides to Ae. albopictus mosquitoes and honey bees were determined.…”