You Are Here: Management Updates 1999 Archive July 30, 1999

Date: July 30, 1999
Category: Insects
Subject: Cutworms & Webworms, White Grubs, Chinch Bugs & Billbugs

One superintendent I talked with yesterday (29 July) reported that he has had 0.3 inches of rain since the end of May. His course is in Westchester County, NY, but many of you are facing the same challenges, and we don't see any breaks coming soon.

CUTWORMS AND WEBWORMS - As I was mowing my lawn last night, I noticed a large number of webworm moths flying, perhaps the highest population I have seen in ten years. While most lawns in New England will NOT sustain significant damage from webworm caterpillars, the insects are here, so turf managers should be looking for them now. If my population is any indication, adults are flying now and young caterpillars of the next generation should start showing up about 10 to 14 days from now. If populations are high enough to warrant treatment, MAKE THE APPLICATION AS LATE IN THE DAY AS POSSIBLE and water in lightly. Use a material that will stay in the thatch. The same goes for cutworms - we are seeing some cutworm activity on fairways and greens and tees.

WHITE GRUBS - We have received reports of the first young grubs hatching out. In a dry year such as we are experiencing, many beetles will delay laying their eggs until soil moisture improves. That means grub hatch may well be later than usual and grubs will tend to stay a little deeper in the soil profile, trying to avoid the worst of the dry and hot conditions near the surface. This is a year where watering the areas BEFORE application will help - the moisture will trick grubs into thinking soil moisture is improving and they will move up toward the surface, where they will be more vulnerable to insecticides. The tough part this year will be finding the water! As always, it is absolutely critical to water in the application - perhaps more this year than ever.

Chinch bugs and billbugs are active, but sometimes their activity is misdiagnosed as drought stress. It is probably too late to do anything about billbugs, but a little rain would do wonders. Anybody know how to do an effective rain dance???

- Submitted by: Dr. Pat Vittum