@article {10544,
	title = {Variable host phenology does not pose a barrier to invasive weevils in a northern hardwood forest},
	journal = {Agricultural and Forest Entomology},
	volume = {14},
	number = {3},
	year = {2012},
	month = {August},
	pages = {276-285},
	abstract = {1 A suite of invasive weevils has established in hardwood forests of the North American Great Lakes Region. We quantified patterns of host availability and the capacity of adults to succeed in a system with high host variability both within and between seasons in Michigan, U.S.A. 2 We quantified phenological development of foliage on three host species (sugar maple, Acer saccharum Marshall; ironwood, Ostrya virginiana (Mill.) K. Koch; and raspberry, Rubus spp.). We estimated adult abundance using emergence traps and sweep net sampling over 3 years, and compared field host associations with laboratory choice assays. 3 Host plant phenology varied among species, between years, and in their interactions. The four most common weevils, Phyllobius oblongus (L.), Polydrusus sericeus (Schaller), Barypeithes pellucidus (Boheman) and Sciaphilus asperatus (Bonsdorff), emerged in early to mid-June, in approximately that order. After emergence, each species showed evidence of host preference based on their abundances on foliage. Overall, P. oblongus and B. pellucidus were most prevalent on sugar maple, P. sericeus was most prevalent on ironwood, and S. asperatus was relatively evenly distributed. Laboratory choice tests with P. oblongus and P. sericeus confirmed these preferences. 4 These four invasive species comprised over 99\% of all 12 845 weevils obtained, suggesting displacement of native species. The optimal sampling methods varied among weevil species. 5 These invasive weevils contend with the highly variable conditions of their environment, and also potential phenological asynchrony, via relatively late emergence, even at the cost of lower host quality. Annual variation is greater for numbers of adults than larvae, suggesting that mortality of late instars or pupae is particularly important.},
	keywords = {Barypeithes pellucidus, Phyllobius oblongus, Polydrusus sericeus, Sciaphilus asperatus},
	isbn = {1461-9555},
	author = {Coyle, David R. and Mattson, William J., Jr. and Jordan, Michelle S. and Raffa, Kenneth F.}
}
@article {10540,
	title = {Temporal and Species Variation in Cold Hardiness Among Invasive Rhizophagous Weevils (Coleoptera: Curculionidae) in a Northern Hardwood Forest},
	journal = {Annals of the Entomological Society of America},
	volume = {104},
	number = {1},
	year = {2011},
	month = {January},
	pages = {59-67},
	abstract = {A complex of invasive rhizophagous weevils has established in North American northern hardwood forests. Little is known regarding the overwintering biology of these weevils and thus how cold hardiness and weather affect population dynamics. Field data from winter 2006-2007 showed a decline in larval abundance but an increase in larval weight of the surviving individuals. During winter 2008-2009, we examined several aspects of overwintering biology of Phyllobius oblongus (L.), Polydrusus sericeus (Schaller), and Barypeithes pellucidus (Boheman). Larvae were collected in the Upper Peninsula of Michigan and transported in bulk field soil to the University of Notre Dame, South Bend, IN, for laboratory assays. Supercooling points (SCPs) of P. oblongus and B. pellucidus larvae not in contact with ice were highest in October and lowest in March, but SCPs of larvae that were in contact with ice did not differ among sampling dates. Larval cold tolerance increased over the winter, with 11\% of P. oblongus and 40\% of P. sericeus surviving 24 h at -12[degrees]C. Few B. pellucidus or P. oblongus survived 30 d at temperatures of -3.3[degrees]C or lower. Body water content increased from January to March in P. sericeus and B. pellucidus. Larval hemolymph from all species showed some thermal hysteresis and hexagonal crystal formation, indicative of low levels of antifreeze proteins or glycolipids. These subterranean-dwelling larvae are buffered from ambient winter temperatures, but our data also suggest low levels of freeze avoidance. We discuss how these overwintering strategies may affect adult population dynamics.},
	keywords = {Barypeithes pellucidus, Phyllobius oblongus, Polydrusus sericeus},
	isbn = {0013-8746; 1938-2901},
	author = {Coyle, David R. and Duman, John G. and Raffa, Kenneth F.}
}
