Insects · Coleoptera · Bostrichidae

Lesser Grain Borer

Rhyzopertha dominica

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

A minute cylindrical beetle of reddish brown, its head hidden beneath a rough, hood-shaped pronotum. It is one of the most destructive pests of stored grain: adults and larvae alike bore into and consume the inside of wheat, rice and maize grains.

Size

2 cm – 3 cm

Diet

Herbivore

Feeds mainly on plants.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

GrasslandHerbivore Solitary Insect Grassland

Fun facts

Unlike other grain beetles, the adult also bores into and devours the grains, not just the larva, which multiplies the damage.
It flies well and colonises new silos under its own power, even from several kilometres away.
Its activity generates a characteristic fine dust and raises the temperature and moisture of the grain, which then encourages fungi.
It belongs to the family of wood-boring beetles, hence its cylindrical shape with the head tucked under the thorax, invisible from above.
Unlike the grain weevil, it does fly, and moves between stores and the surrounding farmland and woodland.
Adults reared in crowded cultures fly far more than those reared with space, and the smell of damaged grain and uric acid triggers that migratory urge.
It attacks maize, rice, wheat and any starchy substrate, and has developed resistance to much of the small range of insecticides available.