Ovipositional preferences and larval survival of annual bluegrass weevil, Listronotus maculicollis, on Poa annua and selected bentgrasses (Agrostis spp.)

Abstract

AbstractThe annual bluegrass weevil (ABW), Listronotus maculicollis Kirby (Coleoptera: Curculionidae), is a serious and expanding pest of short‐cut turfgrass on golf courses in eastern North America. Increasing problems with the development of insecticide resistance in this pest highlights the need for more sustainable management approaches. Plant resistance is one of the most promising alternative strategies. Bentgrasses are the dominant grass species on golf course fairways, tees, and putting greens in the areas affected by ABW. But Poa annua L. (Poaceae), a highly invasive weed, often constitutes a large percentage of turf stands in short‐mown golf courses and is thought to be particularly susceptible to ABW. We studied resistance to ABW in four cultivars of creeping bentgrass, Agrostis stolonifera L., and two cultivars each of colonial bentgrass, Agrostis capillaris L., and velvet bentgrass, Agrostis canina L. (Poaceae), in comparison with P. annua by addressing the three major components of resistance: antixenosis (adult ovipositional and feeding preferences), antibiosis (larval survival and growth), and grass tolerance (grass damage). Our findings suggest that antixenosis/non‐preference is at least partially involved in bentgrass resistance to ABW. Even though oviposition was observed in all tested grasses, females laid significantly fewer eggs in Agrostis spp. than in P. annua. Compared to P. annua, Agrostis spp. were also less suitable for larval development with lower numbers of ABW immatures recovered and larvae weighing less and being less advanced in development. Resistance levels to ABW larvae varied significantly among Agrostis spp. and cultivars. Agrostis canina was least preferred by females for oviposition and A. stolonifera was the least suitable for larval survival and development. Agrostis spp., especially A. stolonifera, were more tolerant to ABW feeding than P. annua. Our findings suggest that reduction in P. annua and replacement with Agrostis spp., especially A. stolonifera, wherever feasible should be integral to more sustainable approaches to ABW management.