With sunnier days and warmer temperatures, backyard gardens across Central Texas are teeming with life. It’s an exciting time for gardeners as many summer vegetables have started to flower and set fruit. With so many plants in bloom right now, insects are very active.
Garden-friendly pollinators like bees and butterflies are always welcome, but undoubtedly, there will be a few undesirable insects coming to visit your plants.
If you have a vegetable garden, there is a decent chance you’ll attract leaf beetles. The most common leaf beetles that we have in Texas are cucumber beetles, tomato beetles and potato beetles. They all belong to the chrysomelidae family.
Cucumber beetles are yellow with round, black dots. They are more oval and tapered shaped than a regular ladybug and they have a distinct head. It’s a cute little bug, but don’t be fooled. Leaf beetles hide on the backside of leaves where they spend time chewing holes.
Here in Central Texas, we also have striped cucumber beetles that look similar to their spotted cousins in size, shape, colors and destructive habits.
Leaf beetles eat a variety of plants. They will eat beans, corn, eggplant, melons, peas, potatoes, tomatoes and squash, but are particularly attracted to cucumbers and cantaloupes.
Leaf beetles lay their eggs in the soil at the base of plants. When the larvae hatch they will bore into the roots and start eating. They can lay more than a 1,000 eggs.
An infestation can be very damaging to plants. Root damage will stunt growth and produce weak plants. Full grown leaf beetles will chew ragged holes into the leaves and flowers which prevent fruits from forming.
Younger plants are more affected by leaf beetles than older plants. Older plants can tolerate a little more damage and can lose 25% of their leaves and still be productive plants.
Leaf beetles also transmit disease. Bacterial wilt is a vascular disease that causes plants to wither, shrivel and eventually die. Beetles spread bacterial wilt by eating from infected plants then grazing on healthy plants with their dirty mouthparts as they devour leaves.
Once plants are infected, the bacteria grows inside. As the bacteria reproduces, it starts to clog the vascular system. The disease impedes the flow of water and causes infected plants to dry out from the inside.
Once the plant starts to wither there isn’t a great way to control it. Your best bet is to remove the infected plants. If you catch it early, you might be able to cut off the infected parts and save the plant, but since it affects the vascular system, chances are it has already spread within the plant.
If you have bacterial wilt, remove the plant. to prevent leaf beetles from infecting healthy plants.
Controlling leaf beetles is challenging. Conventional and organic pesticides aren’t particularly effective for leaf beetles. Conventional agricultural pesticides can do more harm than good because they also kill beneficial insects and beetles like ladybugs.
Removing and killing leaf beetles by hand is effective and free. Sticky traps are another option appropriate for organic gardening. Insects are drawn to these yellow traps and become stuck to the adhesive when they land on. They are good for trapping destructive insects, but they do attract and trap other small pollinators like bees, flies, moths and butterflies.
Dusting the base of your plants with diatomaceous earth can prevent leaf beetle eggs and larvae from developing.
In Mid-May, we can plant southern peas, sweet potato slips, okra, cantaloupe, warm season greens, pumpkins, watermelon, and winter squashes.
With 25 years of backyard gardening experience, Julie is a plant and nature enthusiast. She lives in Taylor and hosts the “Plow & Hose Organic Gardening in Central Texas” podcast and radio show that airs on KBSR, Black Sparrow Radio every Saturday and Sunday at 9 am.
