Canadian Forest Service Publications

Host range, attack dynamics, and impact of Cryptorhynchus lapathi (Coleoptera: Curculionidae) on Salix (Salicaceae) spp. 2001. Broberg, C.L.; Borden, J.H.; Humble, L.M. The Canadian Entomologist 133: 119-130.

Year: 2001

Available from: Pacific Forestry Centre

Catalog ID: 21528

Language: English

CFS Availability: Not available through the CFS (click for more information).

Available from the Journal's Web site.
DOI: 10.4039/Ent133119-1

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Abstract

The poplar and willow borer, cryptorhynchus lapathi (L.), known to be present in British Columbia since 1923, primarily attacks species of Salix L. (Salicaceae) and Populus L. (Salicaceae). Larvae bore into stems, causing them to break easily. The impact of the weevil has been rising in recent years becuse of the increasing importance of poplar and will from both economic and ecological perspectives. We conducted a study at 45 locations in British Columbia to determine host use among native Salix spp. and the between- and within-tree dynamics of C. lapathi. there were 11 new host records, but the incidence of attack was similar among species. Attacked trees were larger in general and had more dead wood and stems, more adventitious branches per stem, mroe total breaks per stem, and mroe naturally caused breaks per stem than their attack-free neighbours. Breaks caused by C. lapathi tended to be slightly larger in diameter and lower on the stem than naturally caused breaks. Bases of stems were preferentially attacked, and C. lapathi selected large stems in which to oviposit. As large attack-free trees become less abundant, weevils apparently start to attack small-diameter stems. Although C. lapathi is adversely affecting the health of willows in British Columbia, there is no evidence that any Salix species is threatened by weevil-caused extinction.

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