Entomology Lab News

In my spring update, I mentioned how the 2017 growing was challenging and how excessive rainfall allowed turfgrass insect populations (e.g. annual bluegrass weevils (ABW), white grubs, and crane flies) to increase in number, to go undetected or untreated. I could not have forecasted how much more challenging 2018 would be in terms of insect management.

ABW populations were some of the highest we have seen in a long time. Large rainfall events around the key larvicide applications in the 1st generation (mid- to late-May timings) affected control of many of our go-to products. This likely contributed to denser populations going into the summer and surprisingly, a fair amount of damage occurring late into September and October. The damage caused by white grubs, especially northern masked chafers and Japanese beetles, also hit epic levels. I cannot recall a season where there was more direct (root feeding) damage in September and October.

We continue to work on finding cultural controls for these pests as well as earthworms. A long-term study was initiated this spring at the Valentine Research Center to examine the effect of saponin and acidifying fertilizers, fungicides, and sand topdressing on cast reductions, pH reduction, and thatch dilution.

Research Summary submitted by Ben McGraw, Ph.D., Associate Professor of Turfgrass Entomology