Colorado Potato Beetle

family: chrysomelidae
species: leptinotarsa decemlineata
common names: colorado potato beetle, diabrotica virgifera
hosts: potatoes, solanaceous weeds, eggplants, peppers, tomatoes
notes: subject to hormolygosis.

Agriculture and Agri-Food Canada Insect Identification Sheet No. 10 October 1982 Colorado potato beetle Leptinotarsa decemlineata (Say) The Colorado potato beetle is said to be native to the eastern slopes of the Rocky Mountains. It is now found all across Canada and the U.S. and is the primary pest of potatoes. Injury: Injury is caused by both larvae and adults feeding on the leaves of potatoes and related plants. Unless controlled, they soon strip the foliage of the young plant which results in undeveloped tubers or poor yields.

Life History:

The potato beetles overwinter as adults coming out of the ground at about the same time as young potato plants emerge. They are about 9.5 mm long by 6.4 mm wide and have 10 black stripes running lengthwise on the hard, orange-colored wing covers. The female lays orange-yellow eggs on the underside of leaves in groups of about a dozen. These hatch in 4 to 9 days. The larvae are humpbacked, brick-red with black spots along both sides of their soft bodies. They molt four arial and become fully grown in 2 to 3 weeks. They then burrow about 7.6 cm into the soil to pupate . In southern Ontario adults emerge in 5 to 1 0 days and begin a second generation, but in cooler areas they emerge, feed until late August, then burrow into the top 1 5 to 20 cm of soil for the winter.

Pest Management:

In home gardens, adequate control is possible by picking off adults and egg masses and destroying them. For current control information, consult your local pest management representative

THE FOLLOWING (UNTIL OTHERWISE NOTED) IS FROM: GERBER, H.S. 1983.
MAJOR INSECT AND ALLIED PESTS OF VEGETABLES IN BRITISH COLUMBIA.
MINISTRY OF AGRICULTURE AND FOOD.

Colorado Potato Beetle, Leptinotarsa decemlineata (Say)

First reported in British Columbia in 1911 at Newgate. It occurs in the East and West Kootenay Valleys and westward to and including the southern end of the Okanagan and Similkameen Valleys.

Vegetables Attacked:

Eggplant, pepper, potato, tomato

Injury:

Adults and larvae feed voraciously on the foliage, making ragged holes; frequently only mid-ribs and stems remain. Heavy feeding kills the plants or reduces yield.

Insect:

Beetles are 8 mm long, yellow with black stripes. The larvae are hump-backed, orange with black spots, and up to 1 cm long when full grown.

Life History:

There is one generation a year. Beetles overwinter in the soil. Yellow eggs are laid in clusters on the undersides of the leaves of eggplant, pepper, potato, or tomato or on the leaves of related weed plants, including nightshade. Larvae mature in three to four weeks and pupate in the soil. First-generation adults appear in the late summer or fall and feed before overwintering.

Monitoring:

If this pest was present in previous years, walk the fields during the last half of May to detect the adults, and during late June to detect the larva-e. Based on the numbers present, make a decision whether control is needed.

Control:

Control overwintered adults when first observed in late May or delay treatment until larvae appear in late June, thus killing adults and larva with one treatment.

From: mph3@cornell.edu (Mike Hoffmann)
Subject: Re: BIOCONTROL FOR DIABROTICA
To: biocontrol-l@ftpt.br (Multiple recipients of list) Reply-To:
biocontrol-l@ftpt.br

Control of Diabrotica beetles is not easy without the use of insecticides. To my knowledge there are no effective biological controls currently available for adults, although entomopathogenic nematodes may help suppress immatures. Some options this grower may want to try include the use of less
preferred cultivars. The plant breeders here at Cornell and our group have been evaluating breeding lines and cultivars for the past few years. Trap crops, the use of a highly preferred cucurbit cultivar adjacent to a less preferred genotype, to aggregate beetles for more efficient control, may also help.

See: Radin, A. M. & F. A. Drummond. 1994. An evaluation of the potential for the use of trap cropping for control of the striped cucumber beetle, Acalymma vittata (F.) (Coleoptera: Chrysomelidae) J. Agric. Entomol. 11: 95-113. We will be starting a multiple year project to investigate this control tactic. The use of semiochemical baited traps (yellow cups coated with sticker) may also provide some control. We can remove (trap out) about 50% of Acalymma vittatum infestations using a mass trapping technique. The capture rate of Diabrotica spp in the same system is much better, but the traps draw in beetles from surrounding areas. Also keep in mind that cucurbit plants can tolerate considerable direct feeding damage. We have shown that removal of over 50% of the leaf material while plants are small (less than 5 true leaves) does not affect quality or yield.

My responses assume that the grower is only concerned about direct feeding damage. If bacterial wilt is a concern (mostly for cucumbers and melons) then he has very few non chemical options.

Regards,

Mike Hoffmann Cornell University, Ithaca, NY 14853 Tel: (607)
255-1327 FAX: (607) 255-1720

December 12, 1995 EPA AND USDA JOIN WITH OTHERS TO PROMOTE SAFER PESTICIDE
TECHNOLOGIES HERE AND ABROAD TO CONTROL COLORADO POTATO BEETLE

EPA and the U.S. Department of Agriculture (USDA) have entered into a partnership with a number of private businesses, the National Potato Council and the New Jersey Department of Agriculture, and government and private institutions in Poland and the Czech Republic to introduce and demonstrate here and abroad the effectiveness of the latest biocontrol technologies available in integrated pest management programs for controlling the Colorado Potato Beetle, a significant insect pest on potatoes. The project is part of the Administration's Environmental Technology Initiative to promote the use of safer innovative environmental technologies here and abroad.

As part of the project, field demonstration plots will be set up in l996 in Poland, the Czech Republic and in the United States (USDA Beltsville, Md. research laboratory) to encourage growers, producers, cooperatives, small farmers and government agencies in the use of safer alternative pest control strategies to control the potato beetle. Funding for the project includes $2l5,000 from EPA and $70,000 from USDA. Other members of the partnership include: BIOSYS, INC., Palo Alto, Calif; Entotech, INC., Davis, Calif.; Mycotech Corp., Butte, Mont.; Beneficial Insectary, Oak Run, Calif; Bio Base Technologies, Inc., Landesburg, Pa.; Potato Research Institute, Bonin, Poland; Plant Protection Institute, Poznan, Poland; and Potato Research Institute, Havlickuv Brod, Czech Republic.

The Colorado Potato Beetle is the most important insect pest on potatoes in Central and Eastern Europe, causing significant crop loss and reduced production each year. Resistance of the beetle to traditional chemical pesticides is increasing. The region has an urgent need to find alternative methods for controlling this pest. The United States will benefit both from the development and sharing of information on safer, effective methods of pest control, and from the transfer of United States technology to Central and Eastern Europe. The project was chosen for the Environmental Technology Initiative through a competitive, peer reviewed process.