Early Season Insect Control with Professor Pat Vittum, UMass.

• Where are the grubs?: A wet and late season combined with a harsh winter has slightly delayed soil insect development. Areas that were not snow covered during severe low temperatures may have experienced some natural kill. A severe outbreak of European Chafers is being reported in New England and will likely lead to 3 yrs of difficult times and large scale turf loss. This is a new expansion for this pest.
• Who are the grubs?: The northeast has a growing palette of grub species including Jap Beetle, European Chafer (EC), Oriental beetle (OB), and Asiatic Garden Beetle (AGB). This complicates control with products that handle one species better than another. It can also lead to one species emerging as a bigger problem over time.
• How to control grubs?: Dylox remains the only rescue treatment available for existing populations at the 6-8 lb per acre rate. Where Sevin is legal (not in NY for grubs) it has inconsistent. Early season use of Merit will only provide control of Jap Beetle with little to no effectiveness on EC or OB. There are some preliminary reports that Merit is not holding control as long as it once did. The rule of thumb appears to be not to expect more than 6 weeks control of EC or OB.
• The Latest on Annual Bluegrass Weevil: Populations appear to be one week behind normal with the females currently looking for a place to insert her eggs into the sheath of annual bluegrass plants. Once they are inserted within 5-7 days they begin to hatch. There are 5 instars (1/week) the first 2 stay in the plant then the 3rd eat their way out. Nancy Consolie, the former Lab technician in Dan Peck’s Lab in Geneva developed a saline (salt water) flush. 150g of salt in one liter and submerge the entire core. This will irritate the larvae and they will emerge. This is an excellent means of determining if you have missed your spray timing and might see injury. Also the injury might not be obvious now but will likely lead to anthracnose problems if gone unsprayed and undetected. Early perimeter sprays (before mid April) may not longer be effective and may need a second application. Better late than early in this case.

Ó 2004 Cornell University