310 - Comparative activity and efficacy of Sumilarv 0.5G in simulated catch basins against urban mosquito species

Abstract: Mosquito control plays a crucial role in mitigation of mosquito-borne diseases. Larviciding that targets one of the aquatic stages is among the routine practices in mosquito control operations. One of the most extensive and challenging mosquito production sources in urban environments is underground storm drain systems. Along with the research and development of biorational larvicides during the past decades, numerous products based on microbial and insect growth regulators (IGRs) have become available. However, the performance of these products often varies due to product design and challenges associated with urban storm drain systems. The current paper validated the comparative bioactivity and semi-field efficacy for two control release products based on pyriproxyfen and S-methoprene. In laboratory bioassays, pyriproxyfen was significantly more active than S-methoprene against test species, Culex quinquefasciatus Say and Aedes aegypti (L.). Cx. quinquefasciatus was less susceptible than Ae. aegypti to both test materials. During a 22-26-week long semi-field evaluation using the cast concrete simulated catch basins, the inhibition of emergence (IE) pre-treatment and post-treatment in untreated control (UTC) was negligible. The Sumilarv 0.5G applied at 75 g per catch basin provided almost 100% IE consistently, while Altosid XR briquet applied at 1 per catch basin only yielded partial and much lower control with great fluctuations. The Altosid XR briquet had a substantial average residual weight at the end of field evaluation. Results were discussed in relation to the quantitation of pyriproxyfen and S-methoprene in treated water.