Chinch Bug: A Turfgrass Enemy

The most damaging insect pest of St. Augustine grass is the chinch bug.  And depending on the location, one to several generations of chinch bugs can occur each year.

chinch bug

Their damage is caused when they suck the juices from grass blades and inject toxins back into the leaf blade. Chinch bug activity often starts during the drier part of the year in many southern areas and is often first noticed in water-stressed areas such as along sidewalks or in poorly irrigated areas. Therefore, conditions such as poor irrigation design, insufficient watering, or both, help to exacerbate the problem.

What Does a Chinch Bug Look Like?

Adult chinch bugs are about 1/5 of an inch long and black with white patches on the wings.  The white patches can sometimes resemble the shape of an “X” on the back.

chinch bug

The young nymphs range from 1/20 inch long to nearly 1/5 of an inch.  The small nymphs are reddish with a white band across the back, but become black in color as they approach adult size.

Chinch Bug Biology

Adult chinch bugs will sometimes hibernate in the winter.  All stages of life are present year-round in most of the state of Florida due to the warm climate, but the primary time of activity in most states is April through October.

Their eggs are laid in leaf sheaths or pushed into soft soil and other protected places.  In the summer, the eggs hatch in 10 days and the young develop to adults in three weeks.  It takes about 20 chinch bugs per square foot to cause damage.

What Does Chinch Bug Damage Look Like?

Symptoms appear as irregular patches of lawn that resemble drought stress.  These areas gradually turn yellow and then brown.  The dead turf will have a yellowing on the outside margin and the growth of the yellowed grass will be stunted.  Weeds will also begin filling in the dead areas.

chinch bug

If you suspect you may have chinch bugs, call a professional for an inspection immediately.  If left untreated, the damage will continue to spread throughout your lawn.