Bruchidae

Pest type: Primary pest.

Worldwide approx. 1400 species have been described. Approximately 84% of the known hosts of Bruchidae are in the Leguminosae plant family. The remaining hosts are scattered among 31 other families.

Distribution: Worldwide, especially in warm temperate and Mediterranean regions. Bruchidae are found on every major land mass except Antarctica and New Zealand.

Several species of Bruchidae, especially those with a cosmopolitan distribution, are notorious pests of stored leguminous seeds. About 30 species of bruchidae in the world are serious pests, and at least 9 are cosmopolitan as the result of commercial activities. Because they have adapted to oviposit and develop in several hosts, they are inadvertently assisted by humans’ mobility and storage methods.

Identification: Adults, 4-6 mm, are small beetles of a plump oval body shape with long legs and antennae, elytra patterned and not fully covering the abdomen. There is an inner ridge on the lower side of the hind femur with or without spine. The larvae, scrabaeiform, have partly-developed legs. Although the larva is the destructive life stage, descriptions of this form are available for only a few species. For most genera of bruchidae, identification is tedious and difficult because many species are closely related; individuals are small , and dissection of genitalia is often necessary for positive identification. The most remarkable character, however, is a toothed dorsal prothoracic plate that assists the larva in escaping from the egg and gives leverage in penetrating the pod or seed. All bruchidae species for which the first larval instar is known, possess this toothed plate.

Similar species: Other bruchidae

Life cycle: Linked to the cropping cycle and availability of ripening seeds. The eggs are glued individually to the pod. Larvae bore directly into the seed on hatching and develop concealed within the seed. Immature stages are spent inside seeds that have been excavated by larval feeding. Adults will leave a neat hole when existing, are long-lived, survive between crops, do not feed on the commodity and can fly.

Commodities infested: Ripping lentils, broad beans and mung beans, grams and cowpeas. Emergence from dried seed in storage but incapable of reinfestation. Bruchidae larvae feed entirely within seeds, making their detection and control difficult.

Treatment: Controlled Atmosphere for infestation in products
Treatment: Heat Treatment for infestation in buildings