False codling moth (Thaumatotibia leucotreta) is one of the greatest threats to the Southern African citrus industry. Economic loss caused by this pest is estimated to be in the region of R100 million per annum. FCM is indigenous to the Southern African region. Consequently, FCM is a threat to many countries that import our fruit. This makes FCM a phytosanitary pest which has lead to stringent export restrictions. It is thus critical that fruit to be exported is not infested with this pest.

Appearance and Biology
Female FCM lay between 100-250 eggs during their life time (about 1 to 3 weeks) depending on temperature and food supply (Figure 1). Eggs hatch after 4-8 days which is also temperature dependant. Newly emerged larvae (white in colour with a black head) burrow into the fruit and develop through five stages. During this time larvae feed on the pith of the fruit leaving a rotting cavity. Often excrement (frass) is visible alongside the cavity. Once the larvae is ready to pupate (pink in colour), it exits the fruit and drops to the ground (Figure 2). The life cycle of FCM is approximately 50 days from egg to adult, but can vary from 30-100 days depending on temperature (Figure 3).

Damage
FCM lay their eggs on fruitlets soon after petal drop resulting in populations of FCM peaking during the period from December to March. Once the FCM larva has entered the fruit it will feed on the rind and pith for the duration of development. This causes premature ripening of fruit and eventual fruit drop. Fruit that are infested with FCM close to harvest may be inadvertently packed and shipped resulting in post-harvest decay.

Seasonal History
Given a constant food source, it is possible for FCM to have a year round continuous life cycle. However, if orchard sanitation is performed correctly and efficiently, populations will decline after the harvest is complete. The life cycle of FCM in winter is considerably extended due to lower temperatures.

Control
FCM was classified as a pest in 1901. Since then many techniques have been employed in an attempt to provide control. In the past, FCM populations were controlled using various chemicals, such as, insect growth regulators. Due to residue restrictions imposed by export markets and the development of resistance by the pest to many of these chemicals, chemical programmes used in the past are no longer applicable. Alternative, softer means of control have therefore become important. These include the use of pheromones, viruses, insect control agents and the sterile insect technique. All of these control measures must be coupled with good orchard sanitation.