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University of Illinois

The dreaded squash bug

FOR IMMEDIATE RELEASE
June 15, 2014

The dreaded squash bug is inevitable if you are growing squash, melons and pumpkins says Horticulture Educator, Kelly Allsup. It is responsible for major crop failure and causes hysterical gardeners running to buy chemicals in which to kill them. Besides this issue these crops can be really easy for even a novice gardener.

Adults and the younger nymphs of the Squash bug use piercing mouthparts to suck the sap from the leaves and fruits causing moderate to severe plant damage. The feeding damage causes spots, yellowing and browning of leaves and fruits. Ultimately, the runners or side shoots of the plant can be destroyed the crop can be decimated by a large population. Adult squash look like stink bugs but only emit an odor when crushed.

Plant debris and leaf litter left in the yard provides shelter for overwintering squash bug adults. During the spring and summer months, they begin to lay orange colored eggs on the under sides of your squash leaves and stems in a very precise pattern. Spider looking nymphs will begin to hatch in 1-2 weeks. They have the unusual habit of staying clumped together when first hatched before they disperse to look for food.

University of Illinois extension Horticulture Educator Kelly Allsup has several cultural to reduce the devastation of this garden pest.

-Lay down wooden boards to lure adults as part of detection

-Don’t Grow Squash. Seriously skipping this summer’s crop can reduce potential outbreaks in next year’s crop.

-Keep plants healthy with proper fertilizing 2-3 weeks after planting and again when they flower

-Put a protective plant cloth over plants for first 4 weeks of crop life creating an impermeable barrier with bricks. This plant cloth allows in sunlight and water and can be adjusted for growth while preventing egg laying during prime egg laying time.  Remove when flowering to allow for pollination.

-Remove areas for adult squash bugs to over-winter by cleaning up garden debris, leaf piles and wooden boards and logs.

-Inspecting the leaves weekly for eggs and nymphs. Pinch off leaves or spray with insecticidal soap and neem oil. Spray at night to avoid unfavorable effects to pollinators and honey bees.

-Grow off the ground on trellis but beware of too much wind

-Plant flowering annuals to attract beneficial insects like tachinid fly (Trichopoda pennipes) that lays its pale-colored and oval eggs on the underside or sides of large nymph and adult squash bugs

With a little planning now, squash bugs don’t have to ruin your summer plans of dining on beautiful zucchinis, fresh watermelon and fall pumpkins.

Source: Kelly Allsup, Extension Educator, Horticulture, kallsup@illinois.edu

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