Biological Activity of Sumilarv 0.5G against Anopheles gambiae sensu stricto and Anopheles arabiensis in Northern Tanzania

Abstract

Background: Sumilarv 0.5G (Sumitomo Chemical Co., Ltd., Tokyo, Japan) is a granular insecticide developed for the control of mosquito and fly aquatic stages. The active ingredient is pyriproxyfen (4-phenoxyphenyl (RS)-2-(2 – pyridyloxy) propyl ether), a juvenile hormone analogue that acts as an insect growth regulator. Sumilarv 0.5G functions by inhibition of adult emergence from pupae. In this study, the Tropical Pesticides Research Institute in Tanzania carried out laboratory, semifield, and full-field evaluation on a new candidate of pupicide, Sumilarv 0.5G. The present study, therefore, sought to test the bioefficacy of Sumilarv 0.5G in laboratory, semifield, and full-field conditions in Mabogini, northern Tanzania. Methods: Standard World Health Organization laboratory bioefficacy evaluations of Sumilarv 0.5G and untreated microcosms were prepared and monitored for inhibition of the larvae introduced to the habitats, while field plots were monitored for 5 weeks after the introduction of Sumilarv 0.5G using manufacturer-recommended doses. Results: Sumilarv 0.5G biolarvicide was highly efficacious in its pupicidal effect, with an adult emergence inhibition rate of up to 90% in all conditions. In both laboratory and semifield experiments, the emergence inhibition was dose-dependent, with the lowest adult emergence being recorded in association with the highest Sumilarv 0.5G dose of 0.03 ppm of active ingredient. Under field conditions, the application rate recommended by the manufacturer – 5 mg ai per m2 – reduced the adult emergence rate by 90% to 96% for up to 5 weeks. Conclusion: We demonstrated the long-lasting biological activity of Sumilarv 0.5G under field conditions. Notably, the field efficacy was attained using the recommended dose of 5 mg per m2, thus making it economical to apply this product, which is capable of inhibiting mosquito productivity in natural habitats for longer periods than achieved by existing products, the efficacy of which is usually about 1 week.

Biological and Residual Activity of Candidate Larvicide Formulation, SumiLarv TM 2MR, against an Exotic Invasive Mosquito Anopheles stephensi Liston in Ethiopia

“…The study revealed that SumiLarv 0.5G achieved complete emergence inhibition for three weeks, with residual activity lasting up to six weeks under semi-eld conditions of plastic containers, with 50% water replaced weekly. This nding aligns with previous research by 20 indicating SumiLarv 0.5G's effectiveness in inhibiting adult emergence for ve weeks period in An. gambiae s.s.…”

“…Additionally, ndings from 11 in Kenya suggested that a concentration of 2g SumiLarv 0.5G per 1000L effectively prevented mosquito re-infestation for three months. Similarly, studies in Tanzania indicated high e cacy of SumiLarv 0.5G in pupiciding over a period of up to ve weeks 20 .…”

“…The residual impact of SumiLarv 0.5G observed here aligns with previous reports on its e cacy against An. stephensi and other mosquito species [20][21][22][23] . Additionally, nearly 100% inhibition of emergence over 90 days using SumiLarv 0.5G granules at higher concentrations, even with water removal and addition and regardless of larval density 24 .…”