By Ayanava Majumdar, Rammohan Balusu and Neil Kelly
Many pests feed on squash from seedling to harvest. They are generally broken down into two groups: the chewing insects and the sucking insects. Chewing insects of squash consist of common pests like cucumber beetle, squash vine borer larva and pickleworm. Sucking insect pests consist of aphids, squash bugs and whiteflies. The pests a squash grower experiences may depend on location.
PREVENTION STRATEGIES
Remember that prevention of pests is the No. 1 goal of organic integrated pest management (IPM) systems. Rapid control after pest establishment becomes a difficult aim later in the production season. Cultural control tactics that include selecting virus-resistant varieties, timely planting and harvest (reduces pickleworm buildup), crop rotation and timely removal of crop debris after harvest (reduces squash vine borer buildup), consistent irrigation and trap cropping are some basic preventive approaches, also called Level 1 control.
Perimeter trap cropping with Baby Blue and New England Hubbard squash in a mixed system is effective in reducing cucumber beetle and squash bug damage to yellow squash (main crop).
PEST EXCLUSION FABRIC
For Level 2 control, growers should use temporary or permanent pest exclusion fabric to create a barrier between insect pests and the main crop. Two lightweight materials tested in Alabama include the Super-Lite Insect Barrier (Gardens Alive, Inc.) and AgroFabric Pro 19 (Seven Springs Farm, Inc.). Both these materials look like lighter versions of the common row cover used for frost protection, but these materials are much lighter with 85 to 95 percent light and rain penetration.
The trick is to put these light fabrics on low hoops (inverted loops) almost immediately after transplanting or after the seeds have germinated. These materials deflect much of the aphids and squash vine borers that fly early in the season. Squash plants can be grown inside the fabric for several weeks and removed or partially opened when flowering begins. Growers can also release beneficial insects like lacewings and lady beetles under the fabric for controlling accidental pest infestations.
For both trap crops and pest exclusion tactics, check out the short IPM videos on the Beginning Farm Project channel at www.youtube.com/playlist?list=PLkNoAmOtt___MKj6IBxvWzOdWP0btBq4D.
INSECTICIDE USE
Growers also have a wide range of organic insecticides to choose from (Level 3 control). See the Organic Materials Review Institute website (www.omri.org) to find hundreds of approved organic products.
Remember to scout squash crops for timely pest detection and identification, then use insecticides per the label with equipment that gives good coverage. For example, highly mobile squash bug adults are difficult to control with natural pyrethrin and spinosad, but the flightless small nymphs are far better targets for organic spray applications.
Several premix insecticides are available commercially today in a variety of packaging, making them affordable for farmers. Squash vine borer and pickleworm larvae are internal pests, which are difficult to manage with topical spray applications. Initiate timely sprays with targeted placement where insect pests are hidden.
Don’t quit spraying too soon since weather patterns can reduce insecticide persistence. Always spray in the evening hours when bees are not around and so that the solution can dry out overnight. Stop spray applications of organic materials when pests become inactive. You can save on the cost of insecticides and protect natural enemies this way.
Finally, it is recommended that growers get in touch with Extension personnel in their state to develop an IPM strategy suitable for their farm. Producers in Alabama can download the Farming Basics mobile app to keep in touch with Alabama Extension. Subscribe to the Alabama IPM Communicator e-newsletter (www.aces.edu/ipmcommunicator) to stay informed throughout the season.