ANGOUMOIS GRAIN MOTH Sitotroga cerealella

This insect, which now occurs throughout the world, was first discovered destroying grain in the Angoumois province of France. (Too bad they didn't find it in a place that was easier to spell).

The moth will lay eggs (up to 300 per female) in a wide range of seeds and grains. Infestations can start in the field before harvest. Old, damp grain seems to be the prefered site. This insect can remain active at low temperatures, so it can continue to damage grain during the winter. Infested grain has a sickening smell and bad taste so animals won't eat it.

Biology

Eggs hatch in about a week. The larva chews into the kernel and feeds for about 3 weeks. They pupate in a silken cocoon in the cavity they created in the seed. The adult emerges about 2 weeks later through a round hole in the kernel. This insect can develop only in whole kernels or caked material. It cannot develop in loose fines or flour.

The adults are small tan moths which can be seen flying around or crawling over the grain surface. The fringes on the hind wings and a finger-like lobe are good characters for recognizing this insect. A commercial pheromone can be used to monitor for males and to detect infestations.