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Listronotus maculicollis
annual bluegrass weevil
Listronotus maculicollis, the annual bluegrass weevil, is a highly destructive pest of short-mown turfgrass in eastern North America, particularly golf course putting greens, fairways, and tee boxes. Adults are small (up to 4.5 mm), dark-colored weevils with a distinct spotted or maculate pronotum. The species has expanded its range from the northeastern United States into the Midwest and Southeast since the 2000s. Larval feeding causes severe damage, with early instars acting as stem-borers and later instars feeding on the crown, resulting in irregular patches of dead turf. The weevil shows strong preference for Poa annua (annual bluegrass) over other turfgrass species, though it can develop on several cool-season grasses. Temperature, not photoperiod, drives daily activity patterns, with peak activity occurring at 14–17°C.