Pests and Diseases: Colorado Potato Beetle


colorado potato beetle
Photo courtesy of


Does this guy look familiar? On our way into church Sunday, my son, Myles, spotted one of these insects and asked “Momma, what is that?”. “It’s a Colorado potato beetle” I replied, wondering why it was there. You know that it’s the season for them when they’re hanging out on the car next to yours in the church parking lot. The name “Colorado potato beetle” may make you think that they’re only a pest of potatoes…it isn’t true. These buggers enjoy all members of the Solanaceae family which includes potatoes, tomatoes and eggplant.

I have found that they do the most damage to my tomatoes when the tomatoes are wee little fellows. Once the tomatoes get above a foot tall, the larvae of the beetles can’t compete with the tomatoes’ rapid growth. Here’s a picture of the larvae…they look nothing like their adult counterparts.


colorado potato beetle
Photo courtesy of


But eggplants are usually more of a pipe dream in our garden than a reality. Last year, the Colorado potato beetles stripped the leaves off before the plants had a chance at growing. This year, my gardening partners, Sean and Anna, bought some eggplants with some size on them and they are doing wonderful. Perhaps size makes a difference with the eggplants too.

Potatoes are the creme-de-la-creme for the Colorado potato beetle. I guess that’s fitting considering their name, huh? All types of chemicals have been deployed in the battle against Colorado potato beetles through the years including DDT. Who’s hungry?

There are more friendly ways that you can deal with Colorado potato beetles. Let’s look at a few, after we briefly discuss their life cycle. The beetles overwinter in the soil and then emerge in the spring to lay their eggs. The females lay bright orange egg masses on the undersides of the leaves. When these eggs hatch, the larvae feed on the leaves and after 10-20 days, depending on the temperature, the mature larvae drop from the plants and enter the soil to pupate. After a few days in the soil they emerge as full on adults. This first set of adults repeat the pattern and they finish the season by overwintering in the soil. To the control measures:

  1. Rotate your crops. Due to the fact that the adults emerge in the spring ready to carry on the love affair with your plants, be sure to not plant members of the Solanacaea family in the same plot as last year.
  2. Hand pick the larvae and adults. You can either put them in soapy water or feed them to your backyard chickens. They’re free protein for your girls if you have them.
  3. Floating row covers. These lightweight covers can save your plants from all sorts of insect pests and Colorado potato beetles are no exception.
  4. Bt. If all else fails, you can apply Bt to control them. Make sure to apply Bt when the larvae are small as this is when control is most effective.


Have you experienced the misery that comes along with a Colorado potato beetle infestation? How have you dealt with them? Send me your ideas or leave me a comment below. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!