Integrated Pest Management Strategies for Squash Pests

Integrated Pest Management (IPM) is defined as an ecosystem-based approach for long-term management of pests. These approaches usually include a combination of strategies that include biological controls, rotation, sanitation practices, and growing pest or disease-resistant varieties. This way of managing garden pests considers the life cycle and biology of the pest so that populations are managed to an acceptable level that will minimize damage to plants or fruits. Below you'll find IPM strategies for managing a couple of the most difficult squash pests in the vegetable garden.

Squash Vine Borer

Squash Vine Borers are one of the most problematic pests for summer squash plants. The adults exist as a clearwing moth, but the larvae is the life stage that does the damage. Eggs laid by the adult will hatch in 10-15 days and the newly hatched larvae will begin to "bore" into plant stems. The affected part of the plant will usually die quickly as the vascular tissues are damaged by the larval feeding.

Squash Vine Borer eggs can overwinter in soils and hatch the following spring when temperatures warm. Tillage is one method to minimize the damage by the overwintering eggs, as it will disturb the eggs and reduce the hatching success rate. Sanitation is also an important practice to manage SVB populations. Be sure to remove all the crop debris from squash plants each season. Only compost the debris if your compost pile gets hot enough to kill any eggs that may remain.

Modifying planting times will also help to control Squash Vine Borer. In the southern states, planting early will help to get strong plants growing before the egg-laying window occurs. In the northern states, planting later and after the egg-laying window will minimize damage. Try not to plant summer squash in the same location in consecutive years, and practice a three-year rotation if possible. If your insect pressure from squash pests is very high, you may consider skipping planting in a given year to reduce the pressure for following years.

Chemical treatment options include spinosad and pyrethroids. Spinosad is an organic option and works well to kill any worm or insect larvae that feeds on plants or fruits. Start spraying when plants are small and at least once a week to kill the larvae before they enter the plants. Once the larvae are inside the plant, they're tough to kill because they're shielded. A pyrethroid like our Bug Buster II is a conventional option for controlling squash pests. It will actually kill the adults and keep them from laying more eggs. With either option, be sure to apply late in the evenings so that pollinators are not affected.

Squash Bugs

Squash Bugs can be problematic on a wide range of cucurbit species including summer squash, winter squash, melons, and more. As opposed to Squash Vine Borers where the larvae do all the damage, mature adults are the culprits within a Squash Bug population. The adults have piercing mouthparts that they use to feed on the stems of the plants. They suck the sap and inhibit the vascular tissues of the plant, often causing eventual demise. One adult will lay 15-40 eggs at a time and the eggs usually hatch in 1-2 weeks.

As with all cucurbit pests, sanitation is an easy-practice to minimize damage in future years. Remove all crop debris and burn it if possible. Try to practice a cucurbit crop rotation so that you're not planting any cucurbits in the same spot in consecutive years -- a three year rotation is best. Tillage will also help to reduce the impact of overwintering eggs in the soil where cucurbits were planted the previous year.

Hand removal of eggs is an easy way to reduce Squash Bu...