Garden plants can be fine despite the insects chewing them – Macomb Daily
Q: I have tomato and pepper plants in my garden that have very small holes in their leaves. Most holes are less than an eighth of an inch. I can’t find any bugs, but the holes keep appearing. What is happening?
A: You are looking for rodents during the day, but your pests work at night. And even if you were out at night, they are very small.
At this time of year, one of the most common insects that chew small holes in the leaves are the flea beetles. Tomato and pepper plants benefit more from the early season action, but broccoli, cauliflower, cabbage, and greens catch mid-season. If the tomatoes and peppers are large enough, the plants are usually not damaged. If the plants are at the four or five leaf stage, they will be strong enough to withstand some damage.
To catch some of your hole-hunters, use yellow sticky boards, sometimes called cards. You can usually buy them at nurseries and garden centers. These are yellow cards covered with a sticky substance that traps insects. Yellow is very attractive to many insects and when they fly to the plateau they stick to it forever.
If the tomatoes and peppers are small, with less than five mature leaves, and you catch more than five flea beetles per card, consider using a pesticide. But spray in the evening when the sun is out on the plants and the flea beetles will be there overnight.
You can use pyrethrin, permethrin, spinosad, carbaryl, malathion, or cyfluthrin. Read and follow mixing and application instructions. Try to avoid spraying, as these pesticides are not selective – they kill both beneficial insects and pests.
But if the plants are larger, control is not necessary. To slow down flea beetle damage next year, plant the plants a little later in the season, when warmer temperatures will allow the plants to grow faster. Plants that grow faster recover from damage faster.
The holes will never go away, but as the season progresses there will be less flea beetle damage on tomatoes and peppers. Keep the plants watered and mulched, fertilize lightly and periodically.
Q: I park my car in the driveway under large walnut trees. Everything was fine until a few weeks ago when I noticed small light spots of something sticky on the windshield and body of the car. These little drops are like syrup. Dirt also sticks to stains. I don’t see anything on the leaves of the trees that suggests the trees are the problem. Could this be some kind of farce? I don’t find that funny.
A: No, it’s not funny and it’s not a joke. They’re insects.
Sucking insects remove sap from the tree by feeding on leaves or twigs. The excess sweet sap is ingested and the excess is excreted with extreme force. The tiny droplets of sticky liquid land on leaves, bark, and anything under trees. In this case, your vehicle.
The sticky, sweet liquid is called honeydew. When the weather is humid, a fungus called sooty mold grows on the honeydew, making the spots dark, like charcoal.
There are a few suspects who do this. The most promising possibility is that of aphids. They are very small and suck the sap from the leaves, while your car grabs the leftovers. Another possibility is mealybugs. They look like buds or bumps and not what most people think of as insects.
Either way, there is nothing you can do about the insect problem because of the height of the trees and not knowing which insect you are feeding. Aphids do little damage to trees, but mealybugs can do more damage. If you want to identify your pests and have them treated, contact a certified arborist. You can find a list online at TreesAreGood.org. You can search by location for members of the International Arboriculture Society.
During this time, find a place to park that is not in the line of sight or wash it more often.
Questions? The MSU Extension Master Gardener direct line is 888-678-3464. Gretchen Voyle is a retired MSU extension horticultural educator.