A weevil of 3-5 mm length; black-brown (red-brown shortly after hatching); the head ends in a slightly curved proboscis; the neck shield has depressed markings and is almost as long as the longitudinally-grooved wing covers.
The entire development takes place within the kernel of grain and is not discernible from the outside; the completely developed weevil then eats its way out of the kernel; the duration of the development phase depends on temperature, normally taking about 8-16 weeks; under favorable conditions it may be as short as 5 weeks. 2-3 broods per year are possible in temperate zones; the weevil connot fly.
World-wide; importance is, however, limited to temperate zones.
The main stored grain pest in countries of the temperate zones. Damage is caused by the adults, but the larvae cause the main damage. Prefers wheat and rye, but also feeds on corn, barley, millet, rice and buckwheat, less on oats; the weevil also occasionally eats flour, whole meal or pasta; after mass infestation, the grain becomes warm and damp, this leading to the formation of mold; kernels damaged by granary weevils offer points of attack for secondary pests.