Environmental Entomology (1987) 16, 752-756

James D. Hansen (1987)
Seasonal history of bluegrass billbug, Sphenophorus parvulus (Coleoptera: Curculionidae), in a range grass nursery
Environmental Entomology 16 (3), 752-756
Abstract: Field data on preimaginal survival of bluegrass billbug, Sphenophorus parvulus Gyllenhal, were collected weekly for three summers, 1982-84, from a hybrid wheat-grass, Elytrigia repens (L.) Nevski x Pseudoroegneria spicata (Pursh) Love, nursery near Kaysville, Utah. Population estimates were based on stem samples for early life stages and soil samples for later life stages. Locations of adult feeding and oviposition on host plants were the same. Seasonal populations were similar in all years except for a rapid decline of late instars in 1983. There was much overlapping of life stages, with early instars extending late into the season. Greatest mortality was during the egg stage (40-75%). Larval mortality was high (49-63%) for the root-feeding middle and late instars. Pupal mortality was low (0-16%) for all seasons. No predators, parasites, or pathological agents were found. Implications of bluegrass billbug successfully attacking an unnatural host, a rangeland wheatgrass, are discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): James D. Hansen

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sphenophorus parvulus	Elymus (crop)	U.S.A. (SW)