You Are Here: Management Updates 2008 Archive June 9, 2008

Date: June 9, 2008
Category: Insects
Subject: Annual Bluegrass (Hyperodes) Weevil

Annual bluegrass weevils finally showing up!
The annual bluegrass weevil (ABW) has been developing fairly slowly in many parts of New England. We pulled samples from Westchester County (NY) on Monday, 2 June, and most of the insects were only medium-sized larvae. As recently as Tuesday of this week, we were finding very small first and second instars in turf samples taken from central Massachusetts. This is about a week behind "normal".

However, we pulled some samples near Hartford, CT yesterday and most of those larvae are medium to full-sized. So it appears that the advancing front of full-sized larvae is making its way into New England.

With the hot weather forecast for the week of 9 June, any golf course superintendent who is seeing decline of annual bluegrass (especially along the edges of greens, tees, and fairways) should take a look and determine whether there are any ABW larvae feeding in the area. The damage will appear quickly with the hot weather.

There are three chemical options for managing larvae: trichlorfon (Dylox™), indoxacarb (Provaunt™), and spinosad (Conserve™). We have the most data on Dylox™, and it normally will reduce larval populations by 40 to 80%. But keep in mind that Dylox™ sometimes can be phytotoxic when applied in very hot conditions, so if possible, you might want to wait until the high temperature "breaks".

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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