Rearing Stored-Product Insects for Laboratory Studies: Lesser Grain Borer, Granary Weevil, Rice Weevil, Sitophilus zeamais, and Angoumois Grain Moth1234

Abstract

Cultures of Rhyzopertha dominica (F.), lesser grain borer; Silophilus granaries (L.), granary weevil; S. oryzne (L.), rice weevil; S. zeamais Motschulsky; and Sitotroga cerealella (Olivier), Angoumois grain moth, were reared in a room maintained at 80±2°F and 55±5% relative humidity on Ramona wheat contained in gallon jars. The moisture of wheat used as media was adjusted to contain 13±0.3% moisture content. Systematic rotation of the lesser grain borer was based on food consumption; rotation of cultures of the other species was based on the age of insects in each. A 30-ml measure of lesser grain borer adults (approximately 9000 live insects) emptied onto 2 quarts of wheat resulted in an average of 29,000 insects per jar in 8 weeks Parent stock of Silophilus spp. was left on 2/½ quarts of media I week, and the same stock was used for 3 consecutive weeks to establish new cultures. Starting with a 40-ml measure of granary weevil adults (approximately 7000), cultures of this species yielded an average of 10,000 insects in 7 weeks; cultures started with a 27-ml measure of the rice weevil (approximately 5200) and a 30ml measure of S. zeamais (approximately 5200) yielded an average of 12,000 insects in 6 weeks. Adult progeny of the Angoumois grain moth began emerging during the third week after 300 moths were placed on 2½pints of wheat. Emergence reached its peak 5 weeks after initial infestation, and an average of 2850 moths was produced in each culture.