So what can we expect from the insects this year?
Looking into a crystal ball and seeing the future is NOT one of my strengths, but here are a few comments on what we saw during the winter that might impact insect activity.
Most of southern New England had very little snow this winter. Even with the snow that fell yesterday, most areas are way below "normal" for snow fall. Those same areas were already in moderate drought at the end of the growing season, so moisture stress may be apparent in April as the turf begins to move out of dormancy.
There were more areas than usual that were exposed (had little or no snow cover) during the winter months. Normally we would hope that insects in open turf areas would experience some natural mortality, but our temperatures were not unusually cold, so I doubt that we will see much reduction in the populations of insects that overwinter in the thatch or close to the surface (annual bluegrass weevils, chinch bugs, bill bugs, and some of the webworms).
The unusually warm weather that occurred about 10 days ago may have spurred some insects into moving around a little earlier than usual. Indeed, we did find a few annual bluegrass weevils when we vacuumed a rough on a golf course near the campus. But those weevils were still in the rough and had not yet reached the fairway. The weather subsequently turned quite a bit cooler, and the weevil migration has slowed considerably.
With regard to annual bluegrass weevil activity, I believe the topsy turvy temperatures of the past two weeks (very warm for a while and now more seasonable) will "average out" and our degree day predictions for insect activity and plant phenology will once again provide a good guide for taking action. We are just beginning to see some color in the buds of some of the hardiest, bravest daffodils. Based on pitfall trap collections from previous years, I would expect some golf course superintendents in southern New England to start seeing some adults in those pitfall traps by the end of this week. But remember that the presence of adults does NOT mean there is reason to panic! Your best bet continues to be to wait until Forsythia reaches that "half green- half gold" stage before applying an adulticide.
White grubs will begin to return to the root zone once the frost leaves the soil. Given the forecasts I am seeing for southern New England, some of you may start seeing European chafer grubs feeding in the roots within the next week or two. (Remember that European chafers are hardier, and more cold tolerant, than the other species, so they will show up first.) The other grub species will not be far behind.
It promises to be an "interesting" year!
Submitted by: Dr. Pat Vittum