You Are Here: Management Updates 2006 Archive August 2, 2006

Date: August 2, 2006
Category: Insects
Subject: Summer Insect FAQ

Some FAQs for this time of year:

1. Where will the grubs be this year?

The answer to this question will depend in part on which species is/are most prevalent in a given location. European chafers normally prefer drier soils (although we did see them thriving after being under water for 10 days last fall). So in general I would expect to see more chafer activity in "higher, drier" locations this year.

In "normal" years we often see less Japanese beetle or oriental beetle grub activity in unirrigated sites, like golf course roughs or less aggressively maintained home lawns. But this year, because of the persistent rains, all turf areas are "at risk" more than usual.

For beetles that have already laid eggs, you might find more activity in areas that drain better, because soil moistures remain quite high in much of New England. But the beetles that are laying eggs actively right now or in the next couple weeks may find soil moistures a bit lower, so they may end up selecting their "usual" sites.

2. Are there more sod webworms than usual this year?

It seems that sod webworm activity is a bit "spotty" this year. I have had a couple reports from readers that moth activity is higher than usual, but in general I suspect it is about "average" in most locations. Keep in mind that the webworm caterpillars often do not cause serious damage in lawn settings, but they certainly can!

3. Are black turfgrass ataenius becoming more active?

I have had a couple samples sent in recently that had black turfgrass ataenius (BTA) grubs. This insect is solely a problem on golf courses, and its incidence seemed to decline when more superintendents began to treat for annual bluegrass weevils. The adult treatment in spring is very effective against both insects. But certainly there were a few golf courses that experienced damage from BTA this summer.

For monitoring purposes, keep in mind that BTA grubs are often present at times of year when other species are not present. First generation BTA may show up any time between mid June and mid July (depending on spring temperatures). Some years we have a second generation. When that is the case, grubs are present from mid July through mid August. Grubs are much smaller than any of the "standard" grubs, even when they are "full sized", and often have a dark grey tinge to them. They tend to prefer low-lying areas or areas with higher levels of organic matter.

4. And what about chinchbugs?

Chinchbugs are active now. Many lawns and other turf areas may go into summer dormancy soon as a response to the extreme heat that is dominating the region. Remember to look - is it just heat-induced dormancy or are there chinchbugs too? On a sunny day you can see chinchbugs moving near the surface of the turf. Disturb the turf lightly with your fingertips and look for movement.

Chinchbugs are fairly vulnerable to several turf insecticides, so if treatment is deemed necessary, there are several alternatives.

Submitted by: Dr. Pat Vittum

DISCLAIMER - As always, it is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The author and the University of Massachusetts are not liable for any consequences of any pesticide "recommendations". Mention of any trade name is not to be considered endorsement of a product.

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