Home gardeners and potato growers can expect to see overwintered Colorado potato beetles on plants by the first week of June. This is according to reports from the state Department of Agriculture, Trade and Consumer Protection.
Managing these early adults will lower egg-laying potential and help reduce crop damage. For small to moderate-scale farms, control methods such as planting a trap crop two weeks in advance of the main crop and destroying the trap crop with a mechanical method, such as a soil chopper, can be effective in combination with other tactics.
Crop rotation and relocating this year’s crop at least ½ mile from last year’s field (if practical) can also help reduce early-season pressure. This insect has developed resistance to several insecticides and effective control requires a varied approach that uses non-chemical methods.
Another familiar vegetable pest now appearing in gardens is the imported cabbageworm.
Adult butterflies have been active since late April, and small larvae have become noticeable on cabbage transplants. DATCP recommends growers inspect gardens and larger cabbage plantings regularly for the yellow eggs laid on plants and velvety green caterpillars with a faint yellow longitudinal stripe. The economic threshold for this pest in cabbage is 30% infestation at the transplant-to-cupping stages.
DATCP also encourages routine inspection of seedlings and recently transplanted vegetables for evidence of black cutworm feeding since larvae are reaching the most damaging plant-cutting stages.
Cutworms feed on the stems of young plants at the soil line and can be destructive where transplants are planted through black plastic or a similar weed barrier. These barriers provide a protective covering for cutworms, making them more difficult to control. Beans, cabbage, carrots, celery, corn, lettuce, peas, peppers, potatoes, and tomatoes are all at risk of injury.
