Garden Update: Late Season Pest Management in the Vegetable Garde

Kathleen Cue, Nebraska Extension Horticulture Educator in Dodge County (Week of August 23, 2021)

This is the season of vegetable abundance and while it would be great if our most pressing concern involved harvest, instead we find vegetable pests are an ongoing problem.

Squash Bugs
This sucking pest reduces leaves to dry crunchiness, interfering with the process of photosynthesis and vegetable production. Where their numbers are small, adult and immature squash bugs can be handpicked from cucumber, melon and squash plants and dropped into a bucket of soapy water.  When populations are high, Neem oil can be applied to the bugs and their eggs (red in color and massed in the “V” of the leaf veins on the undersides of leaves.)  Trap crops of delicata or blue hubbard squash are preferred food sources for squash bugs, minimizing their damage to other crops, so long as gardeners still manage pest numbers in the trap crops.

Squash Vine Borer
No insect causes the collapse of squash vines faster than squash vine borer. Eggs are laid at the base of stems by the adult, a clear wing moth. Hatching caterpillars bore into stems, feeding on water-conducting tissues. Since it is almost impossible to eradicate them once they are in the stems, prevention is key. Wrapping the base of stems with cardboard rolls or strips of aluminum foil will prevent access to stems by the egg-laying female moths.

Cabbage Looper Caterpillar, Diamondback Moth Caterpillar, and Imported Cabbageworm
Caterpillars in this group feed on the leaves of cole crops. Gardeners wanting to get in a second planting of cabbage or broccoli can be frustrated by these insect pests coming to the table with forks in hand.  Initial holes from feeding are gradually enlarged to leave nothing behind but a few leaf veins. Squishing caterpillars between your fingers is certainly satisfying but Dipel (B.t.), Neem oil, or Spinosad will work too.

Blister Beetles
Blister beetles have wide-ranging food preferences among crops, ornamentals, and vegetable gardens, eating holes in the leaves of eggplant and potato. This species is not all bad—blister beetle larvae feed on grasshopper eggs.  The bodies of the blister beetle contain cantharidin, which can cause blisters on skin when insects are crushed.  Their numbers are rarely high enough in vegetable gardens to warrant application of an insecticide so instead, gather blister beetles with a gloved hand and drop them into a bucket of soapy water.

Photo from Alton N. Sparks, Jr. University of Georgia -

Cabbage Looper Caterpillar Photo from Alton N. Sparks, Jr. University of Georgia -