Role of Needles in Close-range Host Selection by the White Pine Weevil on Sitka Spruce

Authors

  • L. J. Harris Centre for Pest Management Department of biological sciences Simon Fraser University Burnaby, BC VSA 1S6
  • R. I. Alfaro Centre for Pest Management Department of biological sciences Simon Fraser University Burnaby, BC VSA 1S6
  • J. H. Borden Centre for Pest Management Department of biological sciences Simon Fraser University Burnaby, BC VSA 1S6

Abstract

The white pine weevil, Pissodes strobi Peck, is apparently induced to feed and oviposit on the cortex of leaders of Sitka spruce, Picea sitchensis (Bong.) Carr, in part through the influence of needles. In laboratory feeding bioassays, mature needles were shown to contain non-volatile feeding deterrents, which probably direct weevils away from them to feed on the bark. In addition, weevils fed more frequently on agar bark discs with spruce needles or toothpicks inserted in them than on control discs, suggesting that the needles have a positive thigmatactic effect on close range host selection.

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