You Are Here: Management Updates 2003 Archive July 8, 2003

Date: July 8, 2003
Category: Insects
Subject: Beetle Adults, Chinchbugs, Bluegrass Billbugs

Beetles flying
With the recent hot spells, several of the scarab beetles are now flying. I had several reports from faithful readers (thank you!) reporting that European chafer adults have been seen flying in very large numbers in the eastern part of Massachusetts. The flights are about a week later than we see in "normal" years, but apparently the heavy rains of June did not cause the chafers any undue difficulty and they are now out and about. Meanwhile I was on a golf course in New Hampshire yesterday (not far from Lake Winnepesaukee) and saw large numbers of Japanese beetle adults emerging from the soil. Each one I checked happened to be male, which makes me think this is just the very beginning of their flights. (Normally males dominate for the first week or so and then female numbers increase throughout the summer.)

So... for those of you who are scheduling grub applications, any time in the next three weeks should be a great time to apply a preventive material like imidacloprid (Merit) or halofenozide (Mach 2). Remember to water the material in thoroughly. And if the hot weather persists for the next few weeks such that lawns and other turf areas begin to go dormant, you will need to remember that part of Merit's activity comes from its systemic qualities. In other words normally some of the material is absorbed through the roots directly into the plant. But if the plants are dormant, that uptake cannot occur. So apply Merit before the turf goes dormant if possible.

Other creepy crawlies
Keep in mind that now we are in the heat of summer and some lawns are beginning to go into dormancy, there are at least two turf insects that are active in New England whose symptoms resemble drought stress. Chinchbugs are active now so remember to look for activity in areas where lawns are looking droughty. Just get down on your hands and knees and part the grass with your fingertips. You can see chinchbugs moving on or near the surface. (The babies are incredibly small, but they are also bright red or orange, so you can see them pretty well.) Chinchbugs love turf with thick thatch (all the more hiding places for them), and usually are most active in areas where soils drain very well or are in direct sunlight. That does not mean you won't find them elsewhere, but the sunny, sandy soils will show activity first - and most severely.

In addition bluegrass billbugs (and probably some other billbug species as well) are becoming active in our turf settings. The larvae (white feeding sacks with brown heads, no legs) will be feeding anywhere from the thatch down through the crowns and roots. They may be as long as a quarter inch when approaching full size. Again the damage looks like drought, but one tell-tale symptom can confirm the presence of billbugs. If you pry through the thatch and see little pockets of sawdust-looking material, you can bet billbug larvae are present. Sometimes the larvae are hard to find, but if you find the sawdust "calling card" (actually it is billbug feces), you will know what you are dealing with. Several insecticides are labeled for billbugs, but normally it gets increasingly difficult to deal with them as we get further into the summer. So take a look now.

- Submitted by: Dr. Pat Vittum