Whenever you have a few minutes, take the time to get up close to your plants. Turn the leaves over to look for eggs or newly hatching insects. Here are some insect pests that show up in gardens every June.
Colorado potato beetles (shown at left) love potatoes, of course, but their favorite crop of all is eggplant, which is related to potatoes. Luckily, they don’t have much appetite for tomatoes, another relative. The eggs are bright orange, about the size of a fat sesame seed and are laid in clusters of 8-12 on the undersides of the leaves. Crush and egg clusters you see. By crushing them now you prevent that whole generation from developing.
Aphids love lupines. Actually, aphids feed on a lot of different flowers and vegetables but they really do love lupines. If you have a mixed flower garden, the first place you’ll find aphids is there. I find they are most interested in the flower stalk and will completely cover the stalk as it begins to bloom. You can knock them off with a hard stream of water or direct a spray of insecticidal soap since they move very slowly. Just don’t use that spray on hot, muggy days or it may harm your plants. As soon as the lupine flowers fade, I cut the entire plant back to the ground. It quickly produces beautiful new growth that is rarely bothered by aphids and lasts the rest of the summer. Be sure to give this a method a try if you grow lupines.
Flea beetles (shown at right) love crucifers, which is the group that includes broccoli, cabbage, cauliflower, Brussels sprouts and Chinese cabbage. I don’t have any easy ways to deal with these pests. They are small, round, black beetles that hop like a flea when you get close, so hand-picking is impossible. They make round ‘bullet holes’ right through the leaf and can wipe out young seedlings. There are some dusts you can use that leave a residue for when the flea beetles hop back that can help. If you have a problem every year you can plant these crops under row cover to keep flea beetles off until the plants are big enough to tolerate some damage.
Cucumber beetles (shown at left), as their name implies feed on cucumbers as well as members of the Cucurbit family such as summer and winter squash, melons and pumpkins. The beetles are particularly damaging at the seedling stage when they devour the young plants when they are the most vulnerable. They are attracted to the color yellow so sticky cards may help but handpicking is impossible since the beetles are quick and numerous. Later in the summer, cucumber beetles can also transmit bacterial wilt, a particular problem for cucumbers.
For control options, including organic and conventional pesticides, contact your local Cornell Cooperative Extension office. When in doubt, bring a sample by their office for a free identification and they can suggest control options tailored to that particular pest.
Photos, from above: a Colorado potato beetle (USDA/Peggy Greb), a flea beetle (USDA/Peggy Greb), and cucumber beetle (USDA/Scott Bauer).