Chemical Mediation of Hunting Billbug (Sphenophorus venatus) Host-Finding and Mating Behavior: Implications for Management in the Transition Zone.

Hunting billbug Sphenophorus venatus damages both warm- and cool-season turfgrasses. Anecdotal evidence suggests that this species is becoming a more serious problem in areas not traditionally in its range. The objectives of this work were to (1) detail S. venatus life cycle in Indiana (2) determine adult host preference amongst various warm- and cool-season grass species and (3) clarify adult behavioral responses to host-plant volatiles and conspecifics. S. venatus successfully overwinters in both the adult and larval stage in Indiana, resulting in two separate developmental cohorts. In feeding assays, S. venatus showed no clear feeding preference for warm- vs cool-season grasses, but did prefer zoysiagrass Zoysia japonica (var. Meyer) over all other species tested; Bermudagrass Cynodon dactylon (var. Patriot), Kentucky bluegrass Poa pratensis (var. Park), and creeping bentgrass Agrostis palustris (var. Penncross). Adult males and females were attracted to male conspecifics in the presence of host plant material (C. dactylon) in binary choice y-tube olfactometer assays, but only adult males were attracted to C. dactylon volatiles alone. Insight into the S. venatus seasonal biology, host preference, and chemical cues that influence foraging and mating behavior may prove useful for the development of monitoring and IPM tools for this insect.