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!




Pests and Diseases: Tomato Hornworm


With all of the warm weather we are having, it makes me think for a moment that I can walk outside and pick a fresh tomato off of the vine. But alas, it’s still January. When the warm weather does arrive, the pests and diseases that want to attack my beloved tomatoes will be lurking, waiting for the perfect opportunity to strike. Today, I want to look at the tomato hornworm so that we can all be prepared for how to deal with this vegetable villain.

tomato hornworm

Tomato hornworm is obviously a fan of tomatoes but they also enjoy other members of the Solanum genus such as Jimson Weed, nightshade and horsenettle. Keep that in mind if you have trouble with tomato hornworm…eliminating the other hosts can help in controlling them on your veggies. They also can be found munching on your peppers and eggplants so beware. These pests could pass for a chameleon relative as there ability to disguise themselves is uncanny…and that’s why they are capable of defoliating large portions of young tomatoes in the blink of an eye.

Tomato hornworm is 3.5″ to 4″ long as a mature caterpillar which is pretty big when you think about it. I’m not a fraidey cat but I must admit that I don’t enjoy squishing them because they are so large. Now give me an aphid and I’m a beast…I can squish them by the hundreds if need be! You really do need to dispose of them instead of tossing them aside and hoping that the birds pick them off. The mature caterpillar will drop off of the plant and then pupate into a moth if you leave them to their own devices.

Tomato hornworm eggs are laid on both the upper and lower sides of the leaves in late spring. If there is a saving grace here it is that they are deposited as single eggs, instead of in large groups. The moth that lays the eggs are known as hummingbird moths or sphinxs. Not all hummingbird moths evolve from tomato hornworms for the record…just some of them.


By far and away the best control method for tomato hornworms is hand picking them. You can either squish them, put them in a bucket of soapy water or feed them to your chickens if you are lucky enough to have them. But as we discussed above, don’t just toss them and hope that nature takes care of them. More than likely, nature will prevail but it will mean that you have a larger population of tomato hornworms instead of the robin consuming them for lunch. The good news is that with regular scouting of your tomatoes, you will be able to quickly notice when the tomato hornworm has invaded your garden. Let me know if you’ve had problems with tomato hornworms in your garden and what you’ve done to remedy the situation. Leave me a comment below or e-mail me at Happy gardening!