Tomato Fruit Borer
The eggs of the tomato fruit borer are yellow-white to brown, about 0.5 mm in diameter and are laid in clusters around floral structures and young leaves. Helicoverpa larvae can feed on any plant tissue but are most likely to attack flowers and fruits. They bore holes into reproductive structures, feed from within the plant and inflict serious damage. Frass is visible around the feeding holes. The growth of secondary pathogens such as bacteria and fungi lead to the rotting of tissues. Young fruits are tunneled by the larvae and also rot and fall.
The aspect of the larvae varies from dark-green to reddish black depending on maturation stage and diet. Their body is speckled with little black spots and they have a dark head. At later maturity stages, lines and bands develop on their bodies. Adults are usually light brown, about 35 mm long, and have a small pale patch in the dark section of the hindwing. its life cycle is influenced by weather conditions. Population peaks during fruit development, resulting in high yield loss.
Trichogramma wasps parasitize the eggs. Microplitis, Heteropelma and Netelia wasps parasitize the larvae. Predatory bugs, ants and spiders also attack the larvae. You can also apply bio-insecticides based on spinosad, nucleopolyhedrovirus, neem oil or Bacillus Thuringiensis.
Always consider an integrated approach with preventive measures together with biological treatments if available. Selective insecticide treatment is the best option to rid the field from the pest without affecting beneficial insects. Use the insecticides chlorantraniliprole, flubendiamide and indoxacarb to reduce populations.