Chinch Bug Damage May Resemble Summer Dormancy

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Dr. Patrician Vittum, Turf Entomology, University of Massachusetts, says that before you assume the lawn you’re managing has gone into summer dormancy, check and see if chinchbugs are at work.

Dr. Vittum posted the following short reminder on the most recent UMass Turftalk.

I have had several reports from lawn care professionals that there has been some chinchbug activity in the Connecticut River valley over the past few weeks. My guess is that the same is true elsewhere in New England!

This is a gentle reminder – if you are seeing turf that looks like it has gone into summer dormancy, take a closer look.

Chinchbug damage resembles summer dormancy, with small patches quickly coalescing into larger patches of straw-colored turf. If you get down on your hands and knees and look closely, you can see chinchbugs moving through the thatch.

Those of you who used one of the pyrethroids earlier in the summer during the very hot weather should be aware that pyrethroids have a "negative temperature coefficient". That is just fancy language to note that they do not work as well at very high temperatures. A colleague of mine (who is an expert in pyrethroids and insects that develop resistance to pyrethroids) confirmed that applications made during that heat spell (when daily highs were in the mid to high 90s) might have been compromised.

So if you used a pyrethroid in early July during the hot weather, it may not have been as effective against chinchbugs as you expected. While we do not normally suggest that you use pyrethroids more than once a year in lawn care, if you are still seeing chinchbug activity in areas that were treated in early July, you may have to re-treat those areas.

To view UMass Turftalk or to subscribe to its enews reminders, click here.