Detection of Pissodes strobi (Coleoptera: Curculiondae) using large-scale 70 mm colour photography

Authors

  • S. P. Taylor British Columbia Forest Service Prince George, B.C. V2L 3H9
  • B. S. Lindgren University of Northern British Columbia Prince George, B.C. V2N 4Z9
  • J. Johnson Timerline Forest Inventory Consultants Prince George, B.C. V2L 3R3

Abstract

A 17 year old white spruce plantation with a current rate of white pine weevil infestation of 23% was photographed using 70 null colour photography at scales of 1:500 and 1:650. The two photo-scales were then interpreted by two different sets of photo-interpreters, with varying degrees of experience, and compared to ground surveys. Results showed that the use of skilled photo-interpreters improved the accuracy of interpretation of current weevil attacks by 18% to 79% over the use of unskilled interpreters. A significant relationship was also observed between the amount of red foliage remaining on the leader and the accuracy of interpretation of current attacks. Large-scale 70 mm photography can detect currently attacked spruce leaders as small as 35 by 30 cm with an accuracy approaching 90% providing at least 30% of the red needles remain on the damaged leader and experienced photo-interpreters assess the results.

Key words: white pine weevil; Pissodes strobi; colour photography; aerial survey

Downloads

Issue

Vol. 92 (1995): Journal of the Entomological Society of British Columbia

Section

Articles

License

Authors who publish with the Journal of the Entomological Society of British Columbia agree to the following terms:

-Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

-Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.

-Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).