Behavioural mechanism of Tuta absoluta towards conspecific-heterospecific infested tomato plants in response to leaf volatiles

Abstract

Tomato is one of the major vegetable grown in Andhra Pradesh especially in Chittoor district. This crop is grown all-round the year. In nature, usually a crop (Tomato) is infested by various pests in which South American Tomato leaf miner, Tuta absoluta is the major one. Along with this the other insect which we find usually is the Serpentine Leaf miner, Liriomyza trifolii. An experiment was conducted to characterize the behavioural mechanism of T. absoluta females by choice and no-choice oviposition assays, olfactometer studies towards the conspecific (T. absoluta infested), heterospecific (L. trifolii infested) and healthy tomato plants. Odour of tomato leaves elicited upwind orientation flight of mated females followed by landing as well as egg laying. In olfactometer, no-choice and choice oviposition experiments, T. absoluta females significantly preferred healthy tomato plants over conspecific and heterospecific infested plants. This clearly indicated that the leaf volatiles released by the healthy as well as infested plants varied and provided information on the suitability of plants as oviposition sites and larval host.