Eggfruit caterpillar

Scientific name

Sceliodes cordalis

Description of adult

Eggfruit caterpillar moths have yellowish-brown patterned wings with a 25mm wingspan. At rest they sit distinctively with the abdomen curled upwards.

Immature stages

Eggs are small, flattened with a low longitudinal ridge. Initially whitish, red markings appear as they develop. Larvae tunnel into the fruit. Young larvae are creamy-white while mature larvae are pink and about 20mm long. The brown pupae are enclosed in tough whitish silken cocoons outside the fruit.

Life history

Eggs, laid mainly on the calyx, hatch in 4–5 days at 25°C. Larvae tunnel into the fruit and remain there until emerging to pupate. At 25°C the larval stage takes 10–17 days and the pupal stage 6–14 days. Eggfruit caterpillar is active all year in warm areas but has a winter diapause in cold climates.

Distribution

Eggfruit caterpillar occurs throughout Australia and in New Zealand.

Host range

Eggplant is the main commercial host but it also occasionally attacks tomato, capsicum and pepino. Solanaceous weeds such as thornapples and quena are hosts.

Damage

Larvae damage eggplant by feeding in the fruit, making extensive tunnels that are usually filled with their excreta. Mature larvae leave a hole (3-4mm diameter) as they exit the fruit to pupate. Damaged fruit will eventually break down and rot.

It is not apparent that a fruit is infested until the mature larva tunnels out, so infested fruit may be harvested and marketed, with the damage only becoming apparent when the larva emerges or when the fruit is cut. High levels of fruit infestation can occur in the field and more than one larva may infest a fruit.

Control

Good farm hygiene, including the destruction of old crops as soon as harvesting is completed and the removal of weed hosts, is important. Isolating crops in space or time hinders the build-up of pest numbers. Egg parasitism by trichogrammatid wasps is helpful provided the wasps are not killed by disruptive insecticide sprays.

Monitoring can be done by examining fruit for eggs or larvae, or by using pheromone traps. Several effective insecticides are available to control eggfruit caterpillar.

Chemical registrations and permits

Check the Australian Pesticides and Veterinary Medicines Authority database for chemicals registered or approved under permit to treat this pest on the target crop in your location. Always read the label and observe withholding periods.