Host Range and Effects of Plant Species on Preference and Fitness of Tuta absoluta (Lepidoptera: Gelechiidae)

Abstract

Tuta absoluta (Meyrick) is one of the most devastating pests of tomato in both open field and greenhouse production settings that significantly reduce yield and quality of the fruit. Being a new invasive pest, information on the pest bio-ecology, including host-rage and effects of plant species on its various fitness traits are virtually lacking. This study involved a field survey to establish the realized host range and laboratory experiments to evaluate the preference for, and fitness effects of T. absoluta on different plant species. In the field, T. absoluta was recovered from only four solanaceous plant species: tomato (Solanum lycopersicum L.), eggplant (S. melongena L.), black nightshade (S. nigrum L.), and gubbain (S. dubium Fr.). In choice and no-choice tests, tomato was the most preferred host of T. absoluta having the highest number of eggs deposited, followed by black nightshade, French bean Phaseolus vulgaris L., and chilli pepper Capsicum frutescens. Larvae developed quickest on tomato followed by black nightshade and French bean. The percentage survival to adulthood was significantly higher on tomato, compared to survival on black nightshade and French bean. Rearing of T. absoluta on tomato or black nightshade had no significant effect on pupal mass and length as well as adult size for both sexes. Fecundity and longevity, as well as oviposition preference of T. absoluta, were not affected by rearing on different plants. These findings confirm the oligophagous nature of the pest with high preference to tomato.