Evaluation of Pyriproxyfen Dissemination via Aedes albopictus From a Point-Source Larvicide Application in Northeast Florida.

Abstract

The Asian tiger mosquito, Aedes albopictus , ranks among the most important vectors of dengue fever, Zika virus, and chikungunya virus. With no specific medications or vaccines available, vector control is the only way to combat these diseases. Autodissemination of the insect growth regulator pyriproxyfen (NyGuard®) from a point-source treatment was evaluated in field settings in northeast Florida. The objective of this study was to investigate the possibility of pyriproxyfen dissemination from a treatment site to nontreated oviposition sites via the skip oviposition behavior of Ae. albopictus. A spray application was made to a tire pile using a Stihl® SR 420 backpack sprayer. Autodissemination oviposition vases containing oak infusion water were positioned in groups of five at 25 to 400 m in 4 transects surrounding the tire pile. Two sets of 5 control vases containing oak infusion water were placed 1,500 m from the tire pile and oak infusion water samples were collected directly from the tire pile. Fifty milliliter samples were extracted from each vase weekly and preserved for pyriproxyfen residue analysis. All vases were analyzed at week 0 (4 h post-treatment), 1, 2, 4, and 6. Overall, there were no differences in pupal mortality between the control and autodissemination vases. The tire pile samples had significantly more mortality (P < 0.0001) out to 4 wk when compared to autodissemination and control vases.