Potato Bug Remedy Neded

Asked July 24, 2013, 9:56 AM EDT

I planted potatoes in my garden this year for the first time. Insects are eating the plants. I have tried a product called Liquid Sevin to no avail. I am currently manually picking the bugs off, I cannot keep up. I destroy large numbers every day, but more seem to hatch each day. I have tried to identify the larva and kill that as well. Unfortunately, i am not able to get them all. I have attached pictures. How can i get rid of these pests for good. Also, the insects have eaten all the leaves off of some of my plants. Does that mean the potatoes will not be edible? Will they stop growing without the leaves? Should I dig up the potatoes right away? They have been in the ground since May 17. I appreciate any help you can provide. Sincerely, John Caggiano

New Castle County Delaware

1 Response

Colorado potato beetles are difficult to control. Hand removal and rotating insecticides are very important. Some beetles will tolerate the insecticide that is used against them. It takes some trial and error to find the best choice for your garden. While individual beetles are not resistant to all insecticides, scattered populations contain resistance to nearly every insecticide. Spraying insecticides will kill the susceptible ones. Continually spraying the same insecticide allows resistant beetles to flourish and can help develop resistance in others. It is therefore important to avoid repeated use of one particular insecticide. Other factors besides insecticide resistance can contribute to control failure. Timing of sprays is critical for control. Overwintering beetles are attracted to fields over a period of several weeks. Spraying an insecticide too early may only control a portion of those beetles. However, waiting until larvae are nearly full-grown also increases the chances of control failure. Small larvae are much easier to control with an insecticide than large ones. Using the correct amount of insecticide as well as obtaining complete coverage of the plants is very important. Insecticides should only be used when needed. Generally, insecticides do not need to be applied unless there is more than an average of one beetle or larva per plant. Additionally, some beneficial insects such as birds, predatory stink bugs, and parasitic flies will help to reduce Colorado potato beetle numbers. Good options for small gardens include crop rotation and hand picking. Look on the underside of the leaves for egg masses and remove before they hatch. See photos of the egg masses in the fact sheet included below. Remember that use of insecticides will harm beneficial insects including pollinators and those that help with potato beetle control. For comprehensive information about Colorado potato beetles and their control, seehttp://www2.ca.uky.edu/entomology/entfacts/ef312.asp

Potatoes can be harvested any time for immediate consumption once the tubers are of sufficient size. Tubers harvested before the plant tops have had a chance to die should be intended for fresh use only. They will have thin skins, and easily bruised. Potatoes intended for storage should be harvested one to two weeks after the vines have died down or have been prematurely cut, but before there is any danger of the ground freezing.