Larinus minutus
Biocontrol agent
Biology
Adults are active from May to September. They are 4 to 5 mm long. Females produce 30-130 eggs in their lifetime. Up to 5 eggs are deposited in the flower head of each knapweed plant. Larvae hatch in 3 days and then spend 4 weeks in the seed head before pupating. Pupation takes 1 week. Adults drop off of plants in September and overwinter in the soil.
Destructive Stage
Larvae (feeding on seed head) and adult (leaf and seed feeding)
Impact To Host
Damage can reduce stand density and provide excellent control. L. minutus will be most effective when released with other knapweed biological control agents.
Redistribution
Adult L. minutus can be collected using a sweep net or by picking them off of plants in June and July. A typical release is 150-250 adult insects.
