By Colleen Cavagna, Cornell Cooperative Extension Community Educator
Right now is the time that many insect pests are appearing in our gardens. Gardeners are always fighting the battle with weeds, but savvy gardeners are out scouting their gardens on a regular basis for insect intruders.
Here are a few insects you should keep an eye out for:
Colorado Potato Beetle: If you have them in your garden, the adults are busy mating and laying eggs on the underside of the leaves of potatoes, tomatoes, peppers and eggplant. The adults are quite large and easy to find and have distinctive markings. If you find them on your plants, you can crush them or if you are more tenderhearted than I am, you can drop them in a container of soapy water.
If you have found adults, you should also scout for egg masses. Gently lift the leaves of your plants and inspect the underside for masses of orange eggs. You need to get rid of the adults and eggs, otherwise you will soon have the distinctive red larvae (it looks like a hunched back bug) eating your plants down to the veins. They are voracious eaters and something you want to keep in check, before they have a chance to increase their numbers.
Cucumber Beetle: There are two types, spotted and striped. Both types are carriers of bacterial wilt, a serious disease of cucurbits (cucumbers, squash, melon, pumpkins and related plants) that can kill your plants within days.
The adults feed on cucurbit plants as they are emerging from their seeds and can even kill them before they have a chance to grow. Later in the season, adults are known to feed on the flower’s pistils destroying the flower as well as the fruits. You need to find them and eradicate them early before they mate and lay their eggs at the base of their favorite plants. When the larvae hatch they burrow into the stem, both above and below ground, causing damage.
Look around the base of the plants, near their root systems and on the leaves. These beetles will fly if they feel they are in danger, so be quick when catching them. Both insects can drop straight down when disturbed to avoid detection, so if they suddenly disappear, look at the base of the plant and you may see them trying to scurrying away. There are also chemical pesticides that will work if you have a heavy infestation.
Flea Beetles: These appear as small dark spots on the leaves of plants until you get close. Then they spring off the plants just like a flea. They actually prefer the cole family — broccoli, cabbage, cauliflower and they love radishes. However, if their favorite foods are not available, they will eat other plants as well. They chew small holes into the leaves giving the appearance that the leaf has been shot with small pellets. Larvae feed on the roots and tubers of plants.
There are ways to avoid and/or reduce your flea beetle population through physical barriers, insecticides and weed management.
With all this talk of scouting for bad insects, you should be aware there are even more good insects in the garden that you want to encourage such as lady beetles, lacewings and many others that can help reduce the populations of unwanted insects.
Don’t forget to scout at least twice a week or more.