Angoumois Grain Moth
Possibly European in origin, as it first was discovered as a grain pest in the French province of Angoumois, from which it got its common name. It was found infesting grain in the United States in 1728, and now is found worldwide.
The larvae of this species are obligated to feed within whole grains, and damp grain is preferred over dry product. It will infest virtually all types of grains, including corn, rice, wheat, barley, oats, and various other seeds and beans. It will infest grains still in the field, and the larva is able to remain quite active in cold weather, causing a great deal of damage in the winter. Grain that has been infested acquires a foul smell and taste, further adding to the destruction. Females lay between 40 and 300 eggs on the outside of the grains, and larvae then bore inside and seal the entrance hole. The larval stage lasts about 1 month, the pupal stage about 2 weeks, and in warm climates or interior storage areas there can be up to 10 or more generations in a single year.
The adult moth is a very small moth with tan wings that have no specific markings on them. The wings are long and narrow, and the hind wings have a fringe of very long hairs along the lower margin. The very distinctive characteristic that separates this moth from the similar clothes moths is an elongate projection at the outer end of the hind wings, which is easily seen with some magnification. The larvae will be found only within a whole grain, and they are separated from beetle larvae by the presence of a series of “prolegs” along the middle of their body.
Characteristics Important in Control:
An inspection for the source of the larvae should focus on whole grains of any kind, particularly those in a damp condition. In a home setting this should include non-food items such as decorative arrangements of flowers, wheat stalks, or other seeds, as well as seeds used for bird foods. Proper storage of susceptible materials and good stock rotation will prevent the moths from completing their life cycles, and the use of pheromone traps may enhance the inspection process.