Mature larvae begin to pupate in the soil in mid-July. The new adults emerge in late July or early August. These adults may damage late-maturing crops. Flea beetles are most noticeable in the early spring, when the leave overwintering sites to feed on seedlings, and in mid-August, when the new generation of adults emerge. In home gardens, they are most noticeable when they invade gardens as they are forced off nearby swathed fields.
Flea beetles feed most actively when the weather is sunny, warm and dry.
Cool, damp weather reduces the intensity of attack and favours plant growth. In such situations, feeding is usually limited to the tops of plants that are exposed to direct sunshine. He also observed a negative correlation with windspeed and flight. Turnock et al. Most damage to canola is done by the overwintered adult beetles just before or soon after the seedlings have emerged from the soil.