Black striped beetles on your potato plants, information on the garden pest which damages tomato and pepper plants in epidemic proportions.
What is it?
Colorado potato beetles are the garden pest which most vegetable gardeners call the common "potato bug". These insects are of the leptinotarsa decemlineatea species of potato bug and the have been known to reach epidemic proportions in some areas of the nation. The Colorado potato bug originated in the Rocky Mountains, its native territory, and began migrating around the time of the 1800's due to potato plantings increasing in the east. These garden pests spread eastward ever since that time and now can be found in most States.
What does it look like?
The Colorado potato beetle is only about 1/8 in length and it is always black-striped. These garden pests can sometimes look just black and greyish because of the preponderance of stripes, however they have a yellowish-orange body color between their striped markings. The larvae of the Colorado potato beetle are big, fat, and red. The larvae are also humpbacked and typically have two rows of small black dots on their backs. Damage from the Colorado potato beetle arises in the form of chewed leaves, upon which they feed. These insect pests can devour entire potato plantings in a short period of time and have been known to attack other garden vegetables as well. Colorado potato beetles will also feed on the leaves of tomato and pepper plants. It is likely that if your potato plants become infested and you have tomatoes and peppers nearby they will shortly begin showing Colorado potato beetle damage if they haven't already.
How does it manifest?
Adult female Colorado potato beetles lay their eggs on the undersides of potato, tomato and pepper plant leaves in the vegetable garden. The eggs are a bright yellow-orange and easy to spot if you happen to flip up the leaves and look at the undersides. Clusters of these bright eggs will be found, and it is rare that the egg layings do not cover a large portion of the leaf. When larvae hatch from these egg clusters they begin to feed and continue to do so for a period of three to four weeks at which time they pupate. Pupation occurs in the soil for approximately two weeks at which time the mature beetles emerge to begin the feeding and reproduction cycle once again. Typically there are no more than three generations per year, but even one generation of Colorado potato beetles can be devastating to crop yield.
What can you do about it?
At the first sign of Colorado potato beetle damage, you can promptly apply a diazinon, methoxychlor or pyrethrins containing insecticide. Carbaryl has also been used to good effect. Repeat applications at regular 7 day intervals for the duration of the leptinotarsa decemlineatea infestation. Be sure to check other plants in your vegetable garden which are susceptible to Colorado potato beetle damage such as pepper plants and tomatoes. At the end of harvest be sure to diligently discard and destroy all plant debris so that any area where eggs may over winter have been destroyed.
