Efficacy of biorational insecticides against Bemisia tabaci (Genn.) and their selectivity for its parasitoid Encarsia formosa Gahan on Bt cotton

Abstract

The toxicity of seven biorational insecticides [five insect growth regulators (Buprofezin, Fenoxycarb, Pyriproxyfen, Methoxyfenozide, and Tebufenozide) and two oil-extracts of neem and bitter gourd seeds] against Bemisia tabaci and their selectivity for its parasitoid, Encarsia formosa were evaluated in laboratory and field conditions for 2 years (2018–2019) in Pakistan. Toxicity results demonstrate that Pyriproxyfen, Buprofezin, and Fenoxycarb proved to be effective (80–91% mortality and 66.3–84.2% population-reduction) against B. tabaci followed by Methoxyfenozide, Tebufenozide (50–75% mortality and 47.8–52.4% population-reduction), and then oil-extracts of neem and bitter gourd (25–50% mortality and 36.5–39.8% population-reduction) in the laboratory [72 h post-application exposure interval (PAEI)] and field trails (168 h PAEI), respectively. All tested biorationals, except Methoxyfenozide [(slightly-harmful/Class-II), i.e., causing mortality of parasitoids between a range of 25–50%] and Tebufenozide [(moderately-harmful/Class-III), i.e., causing mortality of parasitoids between the ranges of 51–75%], proved harmless/Class-I biorationals at PAEI of 7-days in the field (parasitism-reduction < 25%) and 3-days in the lab (effect < 30%). In laboratory bioassays, exposure of parasitized-pseudopupae and adult-parasitoids to neem and bitter gourd oils demonstrated that these compounds proved harmless/Class-I biorationals (< 30% mortality). Alternatively, Pyriproxyfen, Buprofezin, Fenoxycarb, Methoxyfenozide, and Tebufenozide were slightly-harmful biorationals (30–79% mortality) against the respective stages of E. formosa. We conclude that most of the tested biorationals proved harmless or slightly harmful to E. formosa, except tebufenozide after PAEI of 7-days (168 h) in the field and, therefore, may be used strategically in Integrated Pest Management (IPM) of B. tabaci.

Evaluation of new combi-molecules against insect pests of cotton

“…ha-1 were found superior in controlling the leaf hopper and whiteflies damage [10,11] . Similar findings were confirmed by [12,13] and reported that buperofezin and sulfoxaflor were found more effective against whiteflies at the recommended doses. Pyriproxyfen 10 EC was found better among other treatments against sucking pests of chilli, in another study [14] .…”

Relationship between viruliferous Bemisia tabaci population and disease incidence of Pepper yellow leaf curl Indonesia virus in chili pepper

“…Patra and Hath (2022) reported that insecticide application did not give satisfactory results in controlling B. tabaci. Gogi et al (2021) reported that the increase in B. tabaci population in area where insecticide was applied was due to the decrease of natural competitors caused by wide spectrum insecticide application. Excessive insecticide application gives negative impacts on the environment, including the elimination of natural competitors.…”

Bio-efficacy of Sulfoxaflor and Other Insecticides Against Sucking Pests of Cotton

“…Similarly Gogi et al, 2021 pyriproxyfen and buprofezin were more effective than Methoxyfenozide and tebufenozide in reducing the whitefly population.…”