Scouting for Annual Bluegrass Weevil Adults

Steven McDonaldTurfgrass Disease Solutions, LLC

610.633.1878www.turfgrassdiseasesolutions.com

Annual Bluegrass Weevil

• Pest of fine turf areas – Most damaging to Poa annua. We have also

observed damage to creeping bentgrass.• Over winters as adults in leaf litter and debris.• On warm days these adults migrate out onto fine

turf adults• These adults are the best life stage to target with

insecticide applications (adulticide)

Disclaimer: This is for educational purposes only. Please use all plant protection materials according to manufacturers label.

ABW adults are very small and may be moving through the bottom portions of the leaves. You will need to get down and look closely!

These adults mate while on the surface.

When Forsythia are in full yellow bloom and starting to go green, many entomologist believe is the peak migration of adults to fine turf areas.

2007 ABW Trial Area

Damage appears as wilting, thin turf. I have seen significant damage to creeping bentgrass and Poa annua. The plants will also pull out from the crown very easily. Cut a wedge of affected turf out and examine the thatch/crown/mat area for……..

In 2006 and 2007 damage from first generations appeared in the third week of May until the first week of June (depending onlocation).

Larvae

ABW Pupae

Oftentimes, more than one life stage is present. Here late larvae and pupae.

Callow adults (immature) appear orange to brown. These go on to be the second generation of weevils in late May or June.

WHAT TO LOOK FOR!

• Now (Until 15 May in Mid-Atlantic)-Adults walking on surface- Best spots to look, is fairways near litter and debris- Scouting can also be done using flushing techniques or pit fall trips- Adults are the best stage to target. (more cost effective and higher levels of control)

WHAT TO LOOK FOR!

• After 15 May– All life stages could be present– If you see wilting or unthrifty turf, look in the

thatch– Determine the count and threshold for

damage in that area– If you see damage, determine what life stage

this insect pest is in • For example, all larvae, most callow adults-control

measures may differ!