Grape Flea Beetle

Introduction

Grape flea beetle (Altica spp.) feeds on buds of several species of wild and commercial grapes (Vitis spp.) during early spring. The species of flea beetles that may cause economic losses in commercial grapes in the United States and Canada include Altica chalybea Illiger and A. woodsi Isely (Northeastern North America) and A. torquata LeConte (California and Texas). Both A. chalybea and A. woodsi activity have been reported in Minnesota, but only the presence of A. woodsi has been confirmed. Both species have similar biology, life cycle, and feeding behavior, but there is a slight difference in the oviposition behavior. A. chalybea lay eggs on buds and bark crevices, and A. woodsi on the underside of leaves later in the season. Both species are often found at the same time on the same host plant. Vitis spp. and Virginia creeper, Parthenocissus quinquefolia (L.), are the most common hosts of the grape flea beetle, but several other plants (e.g., apples, ashes, birches, elms, pines, and oaks) may sporadically be used a host.

Description

Grape flea beetles are small insects, only 3-5 mm long, shiny, with enlarged hind legs used for jumping. In the field, they can be identified by their size and coloration. A. chalybea is dark blue or blue-purple, generally larger than A. woodsi, and the body is 3-5 mm long, ovoid, with a length width ratio normally less than 1.8. However, A. woodsi is blue-green with the body length less than 4 mm.

Biology and Life cycle

	Since both species share many similarities in biology and life cycle, the following applies to both species. Altica spp. overwinter as adults under the soil surface, in wood crevices, under stones, sticks or logs, in or around vineyards. Adults emerge from overwintering sites in early spring, late April to mid May, when grapevine buds begin to swell. After feeding on buds for 1-2 weeks, females mate and lay their eggs, with cluster size varying from 1 to 5 eggs each. The color of eggs ranges from yellow to orange. Larvae emerge in about 2 weeks, depending on the weather conditions, and feed on leaves. First instars of A. chalybea feed on the upper side of leaves, while those of A. woodsi feed on the under side of leaves. Between late June and late July, larvae fall on the ground to pupate. The pupation stage occurs just below the soil surface, under litter, at a depth of 1-2 cm. Adults again emerge in late July and early August, feed on grapevine leaves, but do not mate or lay eggs until next spring. As temperatures start to fall, adults move to overwintering sites.
Flea beetle feeding on a bud
Wooly bud stage

Damage

Flea beetle damage

Adults that emerge from overwintering sites cause most of the damage by directly feeding on primary buds, which prevents them from developing into shoots, and also decreases grape yield. The greatest economic loss occurs when beetles feed on buds from bud swell until the first leaf separates from the shoot tip stages. Once shoot growth reaches 3 inches, damage caused by the grape flea beetle normally does not affect yield. Vines on the borders of the vineyard, next to wooded areas, will likely have higher infestations. Weather also affects the intensity of the damage. Cooler springs, extend the period when buds are more susceptible to the beetle feeding, increasing the chances of economic losses caused by the grape flea beetle activity. Although primary damage is caused by adult flea beetle to the developing buds, larval damage can also occur on the foliage (see picture) and is typically limited to several leaves and vines.  Larval damage should not affect grape quality or yield.

Damage from flea beetle larvae

Management

Remove debris and leaf litter on the edges of wooded areas and wastelands located near vineyards to eliminate overwintering sites.

Sampling should be done during bud swell to first-leaf separated from shoot-tip stages (twice a week), by checking for damaged buds and flea beetles. If 5% of the buds are damaged, control measures should be applied.

There are many insecticides that are effective against grape flea beetles. To ensure proper rates and use of insecticides please refer to the most recent edition of the be found in the Midwest Small Fruit Pest Management Handbook, and the product label.

Selected References

2005 Midwest Commercial Small Fruit and Grape spray Guide. OSU Bul. 861. Ohio State University. http://www.hort.purdue.edu/hort/ext/sfg/

2005 New York and Pennsylvania pest management guidelines for grapes. Cornell and Penn State Cooperative Extension. http://lenewa.netsync.net/PUBLIC/Guidelines_2005/Home.htm

Bordelon, B., C. Janssen, and F. Whitford. 1999. Pest Control in grapes. Purdue Pesticide Programs, Purdue University Cooperative Extension Service.

Flaherty, D. L., L. P. Christensen, W. T. Lanini, J. J. Marois, P A. Phillips, and L. T. Wilson. 1992. Grape Pest Management, 2 nd edition. University of California, Division of Agriculture and Natural Resources.

LeSage. L. 2002. Flea beetles of the genus Altica found on grape in Northeastern North America (Coleoptera: Chrysomelidae). J. Entomol. Soc.Ontario 133: 3-46

Taechenberg E. F., and H. Riedl. Grape flea beetle. Integrated Pest Management Program. New York State. http://www.nysipm.cornell.edu/factsheets/grapes/pests/gfb/gfb.html

Waldstein, D., J. F. Moore, L. Kovacs, M. L. Kaps, and P. L. Byers. 2004 Missouri Commercial Grape Pest Management Guide. Southwest Missouri State University.

Weigle, T., G. English-Loeb, W. Wilcox, R. Dunst, B. Shaffer, T. Mitchell, and T. Collins. Crop Profile: Vinifera and French Hybrid Grapes in New York. http://pmep.cce.cornell.edu/fqpa/crop-profiles/vinifera&French.html