The Annona seed wasp Bephratelloides cubensis Ashmead (Hymenoptera: Eurytomidae) is considered an important pest of Annona spp. (soursop, sugar apple, custard apple) in the Caribbean. Seed wasp damage consists of emergence holes (0.10-0.15 cm in diameter) on green fruits. Symptoms of insect damage include small, black holes on the fruit's surface and brown to black decay to the fruit.
Life History
Females are produced from unfertilized eggs. The newly emerged wasp prefers to oviposit on fruit 3-4 cm in diameter. Eggs are ovoid with a short filament at one end and a long filament that extends out of the oviposition puncture at the other end.
They are laid in developing seeds and although many eggs are laid within a single seed, only one mature larva develops. Egg incubation lasts 12 to 14 days. The larva is near white to cream coloured, c-shaped, pointed at both ends, legless, and swollen near the centre. The larva passes through five instars (moults) in 42 to 55 days. The naked pupae are protected by the seed coat and the pupal stage is 12 to 13 days. Larvae, pupae or adults are found inside the seeds. The emerging adult females tunnel through the pulp and when they emerge are most active in mid to late afternoon. Female body length ranges from 0.6-0.8 cm and they are reddish brown or light brown in colour.
Economic damage occurs when the wasps chew their way out of the fruit, creating a 2 mm diameter tunnel that provides entry for other insects and decay organisms. Dry fruit rot or mummification of the fruit is caused by anthracnose (Colletotricum gloeosporioides) and usually fruit are colonized by these fungi after emergence of the adult wasp. The severity of this disease is probably doubled by the seed wasp infestation.
Control
Malathion® (Malathion) and Orthene® (acephate) are effective in controlling the seed wasp adults in the field. However, sprays do not prevent fruit infestation. Bagging individual fruit in small paper lunch bags will prevent the wasp from infesting the fruit.
In addition, good field sanitation is critical for wasp control. Pick up any fallen and decaying fruit and seeds and burn them. If you cannot burn in your area, place collected material in a strong clear plastic bag and tie the mouth. Leave the bag in the sun for about 2 weeks to cook before disposing or composting. This must be done on a regular basis to reduce the wasp population.