Facts, Identification & Control
Although commonly referred to as bean weevils, the Acanthoscelides obtectus technically belongs to a cadre of seed beetles. In comparison to rice and wheat weevils, bean weevils are rounder in form. They are hairy and shaped much like teardrops. Bean weevils also do not possess the telltale jutting snout present on true weevil species.
Bean weevils are faint olive in color, although darker shades may be visible on the wings. Legs are ruddy in appearance, and the hind legs bear spiny protrusions. The antennae of the bean weevil also appear reddish in coloration.
Behavior, Diet & Habits
Bean weevils will feed on most any available food source, including peas, cowpeas, lentils and other legumes. Farmers may unknowingly mistake infested beans for healthy ones, as the presence of bean weevils is not commonly recognized until empty husks are found within harvested crops.
Female specimens penetrate developing bean pods in order to lay eggs. The entry portals are then sealed, and hairy, white larvae are left inside to develop. In favorable, warm conditions, larvae feed on the bean within which they were laid until only the husk remains. Following pupation, newly developed adults pierce through the bean in order to emerge. Through this process, beans are destroyed.
Signs of Bean Weevil Infestation
Signs of bean weevil activity would be the adults themselves and the damaged beans.
These weevils may enter homes in search of food. Because they are attracted to light, bean weevils can be found near windows of infested structures. To prevent been weevil infestations, stored foods should be kept in leak-proof glass, metal or hard plastic containers.
If a bean weevil infestation is found within your home, it may be useful to sweep or vacuum infested areas. Infested products should be discarded. Contact your local pest control professional to discuss efficient eradication methods.