What is "bean weevil"

Bean \Bean\ (b[=e]n), n. [OE. bene, AS. be['a]n; akin to D. boon, G. bohne, OHG. p[=o]na, Icel. baun, Dan. b["o]nne, Sw. b["o]na, and perh. to Russ. bob, L. faba.]

1. (Bot.) A name given to the seed of certain leguminous herbs, chiefly of the genera Faba, Phaseolus, and Dolichos; also, to the herbs.

   Note: The origin and classification of many kinds are still doubtful. Among true beans are: the black-eyed bean and China bean, included in Dolichos Sinensis; black Egyptian bean or hyacinth bean, Dolichos Lablab; the common haricot beans, kidney beans, string beans, and pole beans, all included in Phaseolus vulgaris; the lower bush bean, Phaseolus vulgaris, variety nanus; Lima bean, Phaseolus lunatus; Spanish bean and scarlet runner, Phaseolus multiflorus; Windsor bean, the common bean of England, Faba vulgaris. [1913 Webster] As an article of food beans are classed with vegetables.

2. The popular name of other vegetable seeds or fruits, more or less resembling true beans. Bean aphis (Zo["o]l.), a plant louse ( Aphis fab[ae]) which infests the bean plant. Bean fly (Zo["o]l.), a fly found on bean flowers. Bean goose (Zo["o]l.), a species of goose ( Anser segetum). Bean weevil (Zo["o]l.), a small weevil that in the larval state destroys beans. The American species is Bruchus fab[ae]. Florida bean (Bot.), the seed of Mucuna urens, a West Indian plant. The seeds are washed up on the Florida shore, and are often polished and made into ornaments. Ignatius bean, or St. Ignatius's bean (Bot.), a species of Strychnos. Navy bean, the common dried white bean of commerce; probably so called because an important article of food in the navy. Pea bean, a very small and highly esteemed variety of the edible white bean; -- so called from its size. Sacred bean. See under Sacred. Screw bean. See under Screw. Sea bean.

   1. Same as Florida bean.

   2. A red bean of unknown species used for ornament.

      Tonquin bean, or Tonka bean, the fragrant seed of Dipteryx odorata, a leguminous tree.

      Vanilla bean. See under Vanilla.

n. larvae live in and feed on growing or stored beans [syn: Acanthoscelides obtectus]

The bean weevils or seed beetles are a subfamily (Bruchinae) of beetles, now placed in the family Chrysomelidae, though they have historically been treated as a separate family. They are granivores, and typically infest various kinds of seeds or beans, living for most of their lives inside a single seed. The family includes about 1,350 species found worldwide.

Bean weevils are generally compact and oval in shape, with small heads somewhat bent under. Sizes range from 1 to 22 mm for some tropical species. Colors are usually black or brown, often with mottled patterns. Although their mandibles may be elongated, they do not have the long snouts characteristic of true weevils.

Adults deposit eggs on seeds, then the larvae chew their way into the seed. When ready to pupate, the larvae typically cut an exit hole, then return to their feeding chamber. Adult weevils have a habit of feigning death and dropping from a plant when disturbed.

Host plants tend to be legumes, but species will also be found in Convolvulaceae, Arecaceae, and Malvaceae, and several species are considered pests.

One characteristic of the beetles which can be seen in the photo is that the elytra are short, not quite reaching the tip of the abdomen.

Several species are native to the United Kingdom, but there are also records of several introduced species from stored products in warehouses and dwellings, although these species cannot proliferate outside of heated buildings in that climate.