Author: Gary L. Hein & Frank B. Peairs[1]
Pale striped flea beetle, Systena blanda Melsheimer, damage is very sporadic in dry beans. Populations tend to build up in alfalfa and dry beans, but little is known of the feeding habits of the larval stage of this insect.
Identification (and life cycle/seasonal history)
The pale striped flea beetle is a dark beetle about 1/6 inch long with two pale white stripes running longitudinally on its back. Flea beetles are quick and difficult to see because they will jump off the plants as you approach them. The pale striped flea beetles overwinter as partially grown larvae in the soil. They begin to feed on roots and root hairs as plants begin to germinate in the spring. Adult flea beetles begin to emerge in June, and they are active over an extended period through the late spring and summer. They begin to feed on bean foliage shortly after emergence.
Plant Response and Damage
Adult feeding results in small shot holes (1/16 to 1/8 inch diameter) on leaves and can cause substantial defoliation to young seedlings. Older plants will also be damaged, but seldom will significant leaf area be damaged. Larvae feed on the roots and root hairs of plants, but the extent of damage to beans is not known.
Management Approaches
The risk of serious flea beetle damage is greatest near the previous year’s alfalfa or dry bean fields or where host weeds, such as, poverty weed, bindweed and pigweed are numerous. Monitor beans planted in or near high risk areas for early season damage. Heavy damage in the seedling stage can threaten stand and insecticide treatment should be considered. See the chapter on bean defoliation for additional guidance on assessing damage.
Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.
