False codling moth (Thaumatotibia leucotreta) is native to sub-Saharan Africa and is found in all citrus production areas in Southern Africa. It also occurs on some of the Indian and Atlantic Ocean islands, such as Mauritius and Cape Verde. False codling moth was previously known as Cryptophlebia leucotreta. The reason for this pest’s high pest status is its quarantine status and is not due to the economic losses.
Appearance and life cycle of False codling moth
Eggs are laid singly on the surface of the fruit and resemble a saucer-shaped dome. After a few days the eggs hatch and the neonate larvae finds a suitable place to penetrate the fruit. All five instars of larval development take place inside the fruit. Once the final instar (fifth) is ready to pupate, it exist the fruit and drops to the ground where it pupates in the top layer of the soil. The moths emerge after a couple of weeks. The life cycle varies between 5 weeks to 3 months depending on the time of year and temperature. There are 6 overlapping generations in a year and it also has no diapause.
Damage and symptoms
Larval penetration holes in the fruit can only be found through thorough inspection. In green citrus fruit the peel around the penetration hole eventually assumes a yellow colour. On ripe fruit this area is orange, but eventually becomes sunken and brown as the damage tissue decays. The mature larvae enlarge the hole to leave the fruit and pupate. Excreta can be found within the larvae tunnels in the fruit. An infested fruit usually falls from the tree 3-5 weeks after penetration by the larvae.