Feeding, mating, and egg laying continue until late October. Each female produces about 300 to 400 eggs. Pest Management Cultural Control Red turnip beetle infestations can be reduced or prevented by using good cultural practices. Red turnip beetle infestations originate in stubble fields previously seeded to canola, rapeseed or mustard or in other fields containing heavy stands of weeds of the mustard family, which have not been cultivated in the fall or early the following spring. For this reason, avoid the practice of underseeding canola, rapeseed, or mustard with forages.
Cultivation is an extremely effective means of reducing red turnip beetle eggs, larvae, and pupae.
Cultivation after harvest buries the eggs and when they hatch, the larvae are unable to burrow out of the soil. Fall cultivation may cause 75-100 per cent mortality of newly hatched larvae the following spring. Cultivation also controls the larvae by destroying hosts plants. When the host plants die, most larvae starve to death, for they are incapable of travelling very far for food. A similar situation occurs when herbicides are applied to control volunteer canola, rapeseed, mustard, or weeds of the mustard family while the insect is still in the larval stage.