Host location and selection of lodgepole pine (Pinus contorta) by the Warren root collar weevil (Hylobius warrei ).

The Warren root collar weevil, Hylobius warreni Wood, is a phytophagous pest of conifers in the interior region of British Columbia, particularly lodgepole pine (Pinus contorta var. latifolia). Literature suggests the weevils locate hosts based on vision and random movements, while the mechanisms of host assessment are unknown. Tracking individuals with harmonic radar, I found predominantly random overall movements, while movements during host location were based on tree size and proximity. These results were supported by the analysis of an existing capture-mark-recapture data set. In further experiments, I found that lodgepole pine seedlings under induced stress produced differential concentrations of a number of terpenes based on parental resistance to the mountain pine beetle (Dendroctonus ponderosae), and that weevils fed differentially on branches of different chemical compositions. These findings strengthen the evidence for host location by vision and random movements, and provide new evidence for host assessment involving chemosensory signals. --Leaf ii.