caa a22 4500 388093234 CHVBK 20180307125257.0 cr unu---uuuuu 161130e199910 xx s 000 0 eng 10.4039/Ent131635-5 doi S0008347X00010245 pii (NATIONALLICENCE)cambridge-10.4039/Ent131635-5 WITHIN-TREE DYNAMICS OF MASS ATTACK BY DENDROCTONUS PSEUDOTSUGAE (COLEOPTERA: SCOLYTIDAE) ON ITS HOST [Elektronische Daten] The within-tree scale dynamics of mass attack by the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, on its host were investigated and quantified. Seven similarly sized Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco (Pinaceae), infested as part of several pheromone-induced infestations, were monitored over an entire attack season. Ninety percent of the attacks on mass-attacked trees occurred within 3 weeks of colonization; the remaining 10% occurred gradually over the remaining 7 weeks of the attack season. Vertical attack distribution followed a Gaussian form that shifted upwards on the bole with increasing attack density. The change in attack pattern associated with increasing attack density was investigated for the central vertical portion of the bole, where most attacks occurred, and where the vertical pattern was least variable. At low density, attacks were randomly distributed. As density increased, the distance between attacks decreased, eventually resulting in a uniform distribution. Copyright © Entomological Society of Canada 1999 Prenzel Björn G. Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 Laidlaw William G. Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 Wieser Hal Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 The Canadian Entomologist Cambridge University Press 131/5(1999-10), 635-643 0008-347X 131:5<635 1999 131 TCE https://doi.org/10.4039/Ent131635-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.4039/Ent131635-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Prenzel Björn G. Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 NATIONALLICENCE 700 1- Laidlaw William G. Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 NATIONALLICENCE 700 1- Wieser Hal Department of Chemistry, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4 NATIONALLICENCE 773 0- The Canadian Entomologist Cambridge University Press 131/5(1999-10), 635-643 0008-347X 131:5<635 1999 131 TCE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge