One strategy, two pests: MSU shares cucurbit IPM tips for growers
Combining targeted insecticides with Blue Hubbard trap crops can improve control of cucumber beetles and squash bugs while reducing unnecessary insecticide applications.
Cucurbit growers dealing with both cucumber beetles and squash bugs this season may need to rethink relying on a single insecticide application, according to a new Michigan State University Extension article by entomologist Zsofia Szendrei.
The article explains that the two pests often appear at the same time, yet they belong to different insect groups and do not respond to the same insecticides. As a result, products that perform well against cucumber beetles may be less effective control on squash bugs, making an Integrated Pest Management (IPM) approach crucial.
When both pests exceed treatment thresholds and immediate control is needed, MSU Extension says pyrethroid insecticides containing lambda-cyhalothrin remain one of the most dependable options for managing both pests. However, repeated pyrethroid applications can disrupt beneficials and may contribute to future pest outbreaks, including increased aphid populations later in the growing season.
For growers targeting squash bugs, the article highlights several newer insecticide active ingredients that have shown activity against squash bug nymphs while offering up alternatives to repeated pyrethroid use. Szendrei also stresses the importance of rotating insecticide modes of action to slow resistance development.
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Beyond chemical controls, MSU Extension says deploying Blue Hubbard squash trap crops can be an effective integrated pest management (IPM) strategy for reducing pressure from both cucumber beetles and squash bugs. Research found Blue Hubbard squash to be substantially more attractive to both pests, allowing growers to concentrate management efforts on trap plants instead of treating entire fields.
Extension specialists note that trap crops require active management, with insects removed or controlled before they can reproduce and spread back into the cash crop. Some growers also treat only the trap plants with systemic insecticides, reducing the need for whole-field applications.
MSU Extension concludes that combining trap cropping with targeted insecticide applications may provide the best balance between effective pest control, pollinator conservation and reduced insecticide use for growers facing pressure from both pests.