Field efficacy of Isaria fumosorosea alone and in combination with insecticides against Aleurodicus rugioperculatus on coconut

Abstract

BackgroundThe rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae), an exotic polyphagous pest and its infestation was documented on coconut (Cocos nucifera L.) for the first time in India during 2016. RSW has attained a serious pest on many economically important crop plants due to its damage severity and rapid spread across the country in a short span of time. Hence, an attempt was made to evaluate the efficiency of the entomopathogenic fungus (EPF), Isaria fumosorosea alone as well as in combination with a reduced dose of few insecticides against RSW on coconut to devise a sustainable integrated pest management module. Thirty-two randomly selected RSW-infested coconut palms were labelled, and eight treatments with four replications were used in a randomized complete block design during the summer months (April and May) during 2021. Two sprays were performed at 15-day intervals, at a rate of 5 L/palm, and observations on infestation/palm (%), intensity (%) and mean live colonies of RSW were recorded.ResultsThe results revealed that the combination of I. fumosorosea (ICAR-NBAIR Pfu-5) @ 5 ml/l + profenophos 50 EC @ 2 ml/l spray significantly reduced per cent infestation of RSW (82.97%), per cent intensity of RSW (80.49%) and mean RSW live colonies (79.68%) followed by combination of I. fumosorosea (ICAR-NBAIR Pfu-5) @ 5 ml/l + buprofezin 25% SC @ 1.25 ml/l spray significantly reduced per cent infestation of RSW (79.35%), intensity of RSW (74.79%) and mean RSW live colonies (74.20%) over I. fumosorosea (ICAR-NBAIR Pfu-5) @ 5 ml/l alone and untreated control. A combination of I. fumosorosea (5 ml/l) + profenophos 50 EC (2 ml/l) spray twice at an interval of 15 days was found effective in reducing the RSW population on coconut.ConclusionsThe present study concludes that the RSW can be controlled effectively by I. fumosorosea alone and in combination with novel insecticides at a reduced rate which showed better toxicity, ovicidal action and preserve natural enemies and reduced environmental load of chemical pesticides.