Mango Shoot Borer
Caterpillars of the mango shoot borer penetrate developing inflorescences and tender leaf midribs or shoots, tunneling downwards the stem. Affected plant parts wilt and are susceptible to secondary infections by opportunistic pathogens. The larva is translucent pale-green or brown with a black head. It comes out to feed on soft and tender tissue of new shoots, leaving behind abundant frass around the entrance hole. Brown pupae can be found on plant remains and in the upper portion of soil. Mango and litchi are the only known hosts of this insect.
The damage on the different plant parts is caused mainly by the feeding of the larvae. The adult moths are grayish-black and 8-10 mm in size. They have a brown wedge-like body with long antennae. The wingspan is about 15 mm. Forewings are brown, with crossed shaded bands in different tones of brown, and a pale patch near the wing margin. The hindwings are plain brown. Creamy-white eggs are laid on stems and young shoots. Larvae hatch after 3-7 days, feeding for about 8-10 days until they pupate. After emergence, the adults fly readily to other trees and orchards. Rainfall and increased humidity favor the development of mango shoot borers, while relatively high temperatures inhibit the life cycle of the insect.
When population numbers are low, plant extracts of garlic and chili dissolved in water can be sprayed to ward off caterpillars and reduce shoot borer infestation.
Always consider an integrated approach with preventive measures together with biological treatments if available. Remove affected grafts or seedlings and spray them with either 0.04% monocrotophos, 0.05% dimethoate or 0.1% carbaryl to effectively control the insect. Insecticides such as fenvalerate, permethrin, penthoate and quinalphos can also be used to control mango shoot borer.