HPIPM:Colorado Potato Beetle-P

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Order	Coleoptera
Suborder	Polyphaga
Infraorder	Cucujiformia
Superfamily	Chrysomeloidea
Family	Chrysomelidae
Subfamily	Chrysomelinae
Tribe	Chrysomelini
Subtribe	Doryphorina
Genus	Leptinotarsa

Scientific Name

Leptinotarsa decemlineata

Common Name

Colorado potato beetle

Author: Whitney S. Cranshaw

Identification (and life cycle/seasonal history)

Colorado potato beetle (Leptinotarsa decemlineata) is a moderately large beetle of broadly oval form. It is primarily very light brown colored with black stripes running the length of the body. Adults are sometimes mistaken for the sunflower beetle, but Colorado potato beetle is larger, has all lines running the length of the body (not broken) and is restricted to nightshade family plants.

Winter is spent as an adult under plant debris and other sheltering materials in the general vicinity of previously infested fields. They become active in May and can be present before potatoes emerge. If nightshade weeds are present they will feed on these and have a great preference for hairy nightshade which they will preferentially feed on over any other plant.

Eggs are laid as masses. Colorado potato beetle eggs are yellow-orange and are usually in groups of a couple dozen or more. The larvae that emerge from the eggs are dark red with a black head and feed on the leaves. Development through all the larval stages takes about 3 to 4 weeks and late stage larvae are lighter red. When feeding is complete they move to the soil, dig a small chamber and pupate. Adults emerge a couple weeks later. There is often a second generation that occurs in midsummer. However adult beetles may feed for a few weeks then go into a semi-dormant condition and move to overwintering sites. As a result one or two generations may be produced.

Plant Response to Damage

Colorado potato beetle adults and larvae chew potato foliage. Although plants can compensate for minor defoliation (at least 10% leaf area loss) extensive defoliation can reduce yields. Plants are more sensitive to defoliation after flowering when top growth has largely ceased.

Natural Controls

Colorado potato beetle seems to be under a high level of natural control. Important natural enemies include the pink spotted lady beetle, which consumes eggs, the twospotted stink bug, a predator of potato beetle larvae, and a tachinid fly parasite of adult potato beetles. Outbreaks of Colorado potato beetle are uncommon in the region in large part due to these natural enemies.

Cultural Controls

Rotation of fields can assist in control of potato beetles. Adults winter around field edges of previously infested fields and may fly long distances, but are less likely to infested if distance to previous potato fields increases.

Chemical Control

Serious problems with insecticide resistant strains are present in much of North America. To date such problems with pesticide resistance in Colorado potato beetle has not been seen in the region and a very wide range of insecticides remain very effective for control.

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.