Transboundary insects of the current decade: potential of biological control in the Indian context

Abstract

The second decade of the 21 century saw five insects, viz. cassava mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Coccomorpha: Pseudococcidae), desert locust Schistocerca gregaria Forskål (Orthoptera: Acrididae), fall armyworm (FAW); Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), rugose spiralling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) and southern American pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) invading India having crossed international borders. While early warning system along with potential of testing Metarhizium acridum (Green Muscle™) through the Food and Agricultural Organisation exists for desert locust, an early importation of parasitoid Anagyrus lopezi De-Santis (Hymenoptera:Encyrtidae) against cassava mealybug is the need of the hour. Documentation of versatile native parasitoids (9), predators (3) and pathogens (6) on FAW implies potential of biological control through conservation and augmentative approaches in maize ecosystems. Fortuitous introduction of Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae) in the late nineties along with an invasive spiralling whitefly Aleurodicus dispersus offering successful biocontrol of rugose spiralling whitefly indicated long-term sustenance of parasitoids in perennial plantations. Nevertheless, the internally feeding invasive southern American pinworm in open fields and protected tomato cultivation need biological products as a component of integrated pest management. A quick response in terms of delimitation and eradication is anticipated for transboundary insects and is only possible through establishment of an operational national digital reporting system with coordination and collaborations of not only all governmental and private stakeholders of plant protection in India, but also forging cooperation at regional and international levels for timely and effective management of transboundary insects.