Eggplant fruit and shoot borer

AVRDC International Cooperators'
Fact Sheet

Eggplant Insect Pests

Eggplant Fruit and Shoot Borer
Leucinodes orbonalis

Found throughout the tropics in Asia and Africa. A minor pest in the Americas.

Damage Symptoms

Wilted shoots are readily visible. There may be small darkened holes surrounded with brownish areas on fruit surface and/or fruit stalk. The inside of the fruit is hollow and filled with frass. The fruit is not marketable.

Insect Characteristics

Chewing mouthparts. The young caterpillar is dull white and turns light pink as it matures. It is 15-18 mm long. The adult moth is white with a pink or bluish tinge and brownish on its wings.

Where to Look

Look for wilted shoots. The larva can be found feeding inside. Fruit damage will not be obvious. The first indication is a small hole in the fruit stalk or in the fruit itself. This is where the insect has entered. Cut the fruit near this entry hole and you will find areas where the larva has tunneled. The tunnels contain frass and insect remains. If you continue to cut around this area you may locate the live larva.

Symptom of shoot attack

Symptom of fruit attack

Technical Information

Creamy-white eggs are laid singly or in groups on the undersides of the leaves, on stems, flower buds, or the base of the fruit. The newly hatched larva prefers to bore directly into the fruit. When feeding is complete pupation occurs on stems, dried shoots, or among fallen leaves. Multiple overlapping generations occur in warm climates. This pest feeds on many other solanaceous plants such as tomato and potato.

Control

Insecticides Sumicidin 20EC, Lannate 90WP, Decis 2.8EC, Sevin 50WP are effective in controlling this pest. Since larvae are only vulnerable for a few hours after hatching, repeated sprays are necessary. Reports of over 80 spray applications per 7-month cropping season have been reported. Such pesticide use pollutes the environment and threatens the health of farmers and consumers. Borers are developing resistance to the chemicals, leading many farmers to create mixtures of numerous pesticides. The widespread use of non-specific insecticides have killed beneficial insect populations, leading to a resurgence of thrip and mite populations.

Alternative approaches are being developed. There has been interest in developing resistant varieties. Eggplant accessions Pusa Purple Long, H-128, H-129, Aushey, Thorn Pendy, Black Pendy, H-165, H-407, Dorley, PPC-17-4, PVR-195, Shyamla Dhepa, and Banaras Long Purple have been reported to be tolerant or resistant.

The use of insect parasitoids, namely Eriborus sinicus, shows promise. But the best non-chemical approach may be mechanical. Prompt removal and destruction of wilted shoots has the potential to reduce insect populations, particularly when conducted on a community-wide basis.

Nylon net barriers may prevent migration of the moth to a crop. The net should be 2 m tall, with a sticky substance such as glue applied over the top 10 cm edging. If glue is not available, extend the net 40 cm over the 2 m height, then bring it out and down to an 80-85 degree angle against the vertical net. The weak-flying adult will remain in the angled area or will be killed by marauding predators.

Since Leucinodes feeds almost exclusively on eggplant, crop rotation can be effective. Stopping planting within a community for 2 seasons will reduce the pest population substantially.

Last updated: 2001.
Information from: Field Guide: Insect Pests of Selected Vegetables in Tropical and Subtropical Asia. 1995. B.L. Parker, N.S. Talekar and M. Skinner. Publication 94-427. Pesticides and other control recommendations should be adapted for local conditions.

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