Annual Bluegrass Weevil (RH) | Turf and Ornamental Entomology Lab

Older adult ABW with scales rubbed off, giving it a jet black appearance. Picture credit: Dr. Kenneth Clayton, University of Kentucky

Older, adult annual bluegrass weevil with its scales rubbed off. Picture credit: Dr. Kenneth Clayton, University of Kentucky.

Annual Bluegrass Weevil

(Listronotus maculicollis (Kirby, 1837))

Rebekka Horn, Graduate Research Assistant, University of Tennessee

William Klingeman, Professor, University of Tennessee

Becky Grubbs Bowling, Assistant Professor & Extension Specialist, University of Tennessee
Midhula Gireesh, Assistant Professor, University of Tennessee

TAKE ACTION!

“Think you have found ABW at your location in Tennessee? If so, please help!”

Currently, we are unaware of any existing populations in ABW in Tennessee. Prior to making a pesticide application, we ask that you collect adult beetle specimens and larvae, take pictures, record the location and possible source of beetles, and reach out to the following:

Dr. Midhula Gireesh (mgireesh@utk.edu),
Dr. Becky Grubbs Bowling (rgrubbs5@utk.edu), and/or
Dr. Bill Klingeman (wklingem@utk.edu)

What are annual bluegrass weevils?

Annual bluegrass weevils (ABW) are non-native beetles that economically and aesthetically affect short-cut annual bluegrass and creeping bentgrass. Areas of concern for this pest include putting greens, fairways, and collars on golf courses. Multiple generations can occur, depending on the location and seasonal weather conditions.

Adult ABW identification

Multiple annual bluegrass weevil adults, captured. — Multiple adult ABW specimens.

Picture credit: Dr. Kenneth Clayton, University of Kentucky.

Newly emerged ABW are mottled brown in appearance, with pale brown and greyish scales. When interacting with the environment, the scales get rubbed off, and older adults are jet black in appearance.

Adults resemble small billbugs. Adults have an elongated snout with antennae that are attached roughly at the midpoint.

Plant phenological indicators also help predict when populations of ABW will be present:

Adults: emerge from overwintering sites when forsythia is in full bloom.
Eggs and early instar larvae: present when the bracts of flowering dogwood are fully open and Eastern redbud trees are in full bloom.
Third and fourth instar larvae: appear in the soil when hybrid Rhodendron catawbienese are in full flower.

flowering dogwood (left) and Eastern redbud (right) — Flowering dogwood (*Cornus florida*) bracts and floral buds (left) and expanding buds of Eastern redbud (*Cercis canadensis*) flowers (right) occurs in late March or early April in eastern Tennessee. Picture credits: Rebekka Horn, University of Tennessee

Full flowering of 'Nova Zembla' Rhododendron — Full flowering of ‘Nova Zembla’ *Rhododendron*, a hybrid with *R. catawbienese* parentage that occurs in late April in eastern Tennessee. Picture credit: Bill Klingeman, University of Tennessee

Lifecycle of ABW

Eggs: Small, rough, oblong, and pale yellow eggs are roughly 0.8-0.25mm in size. Eggs are inserted singly or in multiples between the leaf blade and stem.

Larvae: Larvae develop in 5 larval stages. This is the most damaging life stage of this pest.

Pupae: Pupae are creamy white and eventually darken to a red-brown color. Pupae develop in the soil for ~5-7 days before adults hatch.

Adults: Please see the “Adult ABW Identification” section for more details.

A detailed illustration of the annual bluegrass weevil life cycle. — Annual bluegrass weevil life cycle.

Illustration credit: Rebekka Horn, University of Tennessee

Hosts & damage of ABW

The most susceptible turfgrass hosts include short-cut annual bluegrass and creeping bentgrass.

ABW larvae cause the most damage as they enter the 4th and 5th instars. Late instar larvae move out of the stem to feed on turfgrass crowns. This causes the following damage symptoms, which can be confused with pathogens or drought stress:

Yellowing grass (chlorosis)
Dessication
Dying turfgrass
Post-feeding exit holes in turfgrass stems

Additionally, birds and other mammalian predators may tear up turfgrass while searching for ABW.

Exit hole of annual bluegrass weevil larvae. — Crowning and foliar discoloration of turfgrass resulting from ABW larvae feeding. The arrow indicates the exit hole of the ABW larvae.

Picture credit: Dr. Kenneth Clayton, University of Kentucky.

Damage symptoms of ABW in turfgrass. — Annual bluegrass weevil damage to turfgrass.

Picture credits: Dr. Kenneth Clayton, University of Kentucky.

Monitoring for ABW

Active monitoring for ABW includes the following:

Pitfall trap (pictured below)
Visual surveying
Tug test on turfgrass
Salt flush
Soap flush (pictured below)

As of 2025, Tennessee does not have any infestations of ABW. Please report ABW presence to Dr. Midhula Gireesh, Dr. Becky Bowling, and Dr. Bill Klingeman.

Soap flush designed to draw out ABW adults from turfgrass. — A soap flush being poured onto turfgrass to disturb adult ABW (left), and an adult ABW emerging from the soapy grass (right). Picture credits: (Left picture) C. Sorenson, North Carolina State University; (right picture) Dr. Kenneth Clayton, University of Kentucky.

An example of a pitfall trap, a monitoring technique for adult ABW. — A finished pitfall trap that is not deployed (left) and a deployed pitfall trap (right). Picture credits: Dr. Kenneth Clayton, University of Kentucky.

Management for ABW

Biological control

Entomopathogenic nematodes (Steinernema carpocapsae)

Cultural control

Limiting irrigation
Research and plant resistant cultivars of turfgrass
Check mowing baskets for adult ABW and disposing of the clippings to an off-course location.

Chemical control – the following active ingredients can help control ABW. Please see the review by Brown et al. (2026) for more information:

bifenthrin, clothianidin, dinotefuran, etc.

Resources

Bradley S, Del-Pozo A. 2023. The annual bluegrass weevil as a golf course pest in Virginia (ENTO-565NP). Virginia Cooperative Extension. https://www.pubs.ext.vt.edu/ENTO/ento-565/ento-565.html
Brown MS, Islam T, McGraw B, et al. 2026. Biology, ecology, and management of the annual bluegrass weevil (Coleoptera: Curculionidae) in turfgrass. J. Integr. Pest Manag. 17:pmag002. https://doi.org/10.1093/jipm/pmag002
Clayton K, Larson JL. Revised 3/2026. Annual bluegrass weevil monitoring and scouting techniques. University of Kentucky Department of Entomology (ENTFACT-472). https://entomology.mgcafe.uky.edu/ef472
Cornell University. 2019. Diagnosis and decision making for sustainable annual bluegrass weevil management. https://user-23310503727.cld.bz/Bluegrass-Weevil-Management
Czyzewski BD, McGraw BA. 2017. Mowing height influences Listronotus maculicollis (Coleoptera: Curculionidae) oviposition behavior and mechanical removal from golf course putting greens, but not larval development. J. Econ. Entomol. 110:2165-2171. https://doi.org/10.1093/jee/tox192.
Koppenhöfer AM, Alm SR, Cowles RA, et al. 2012. Controlling annual bluegrass weevil: optimal timing and rates. Golf Course Manag. 80:98-104.
Koppenhöfer AM, Kostromytska OS, Wu S. 2018. Pyrethroid-resistance level affects performance of larvicides and adulticides from different insecticide classes in populations of Listronotus maculicollis (Coleoptera: Curculionidae): split applications and combinations with imidacloprid. Crop Prot. 137:105229. https://doi.org/10.1016/j.cropro.2020.105229
Sousa ALV, Kostromytska OS, Wu S, et al. 2023. Optimizing sampling technique parameters for increased precision and practicality in annual bluegrass weevil population monitoring. Insects. 14:509. https://doi.org/10.3390/insects14060509.
Vittum PJ. 2020. Turfgrass Insects of the United States and Canada, 3^rd ed. Cornell University Press.
Wu S, Kostromytska OS, Koppenhöfer M. 2017. Synergistic combinations of a pyrethroid insecticide and an emulsifiable oil formulation of Beauveria bassiana to overcome insecticide resistance in Listronotus maculicollis(Coleoptera: Curculionidae). J. Econ. Entomol. 110:1794-1802. https://doi.org/10.1093/jee/tox176.