The Other Idaho Bug
Sometimes those brown patches in your lawn are not caused by billbugs or lawn fungus. Another insect that is causing damage to Treasure Valley lawns is the chinch bug. Adult chinch bugs are about one-fifth of an inch long and black with white wings folded over their backs. The insect mates early in the season when the temperature reaches 70 degrees Fahrenheit. The female lays eggs on roots, stems, leaves, leaf sheaths or crevices in nodes and other protected places. Eggs are laid over a 2 to 3 week period, with one female laying as many as 500 eggs.
The young chinch bugs (called nymphs) develop into adults in four to six weeks. Nymphs are yellow upon hatching but soon turn red and have a light colored band across their abdomens. With each molt, nymphs more closely resemble the adults. There are 2 to 4 generations of chinch bugs per year.
The adult chinch bugs insert their slender beak into the grass and suck the plant juices. As the chinch bug sucks the plant juices, they release a toxin that causes yellowish to brownish patches in the turf. The typical injury appears on your grass as the spreading of brown patches of dead grass.
This pest is a sunshine-loving insect and seldom attacks grass in a dense shady area. Discolored areas of grass caused by chinch bug feeding that are in open sunlight several hours daily may be hot spots. Adult chinch bugs can fly, therefore it is difficult to keep an area free of chinch bugs if they are emerging from neighboring lawns, golf courses or nearby croplands.
Inspecting for Chinch Bugs
Scout turf on sunny days by slowly sliding your foot through the sod and watching for the bugs to crawl across your shoe. You can also determine infestations by using a large coffee can or gallon can with both ends removed. Press one end of the can about 2 or 3 inches into the soil, fill with soapy water and watch for about 5 minutes. If chinch bugs are present, they will float to the surface.
The chinch bug sucks sap from grasses; it’s attracted to poorly grown lawns. Chinch bugs start out pencil-tip sized and bright red, with a white band across the back. They darken as they mature, eventually becoming black, ⅛ inch long bugs with white wings. Don’t confuse this pest with its natural enemy, the predaceous big-eyed bug (otherwise known as the Geocoris) the faster-moving predator is wider and has prominent eyes.
A Chinch Bug Overview
- Target: Lawn grasses, corn, and other grasses.
- Damage: Afflicted plants wither and dry out. Dead lawn remains firmly rooted.
- Life Cycle: Adults overwinter in tall grass or debris. When the weather warms in spring, they lay eggs on the grass or in the soil. There are one to seven generations a year.
- Chinch Bug Control: Use Zamzows Chinch Bug Control for an immediate kill and up to three months protection from re-infestation.
- Notes: To see if chinch bugs are present, remove both ends from a large can; then push it into the ground and fill it with water. Let stand for 10 minutes, then check—the bugs will have floated to the top. Before treating, water the lawn to bring bugs to the surface. No treatment is needed if the bugs you see are coated with a gray, cottony material—they’re infected with a fungus