The objectives undertaken in this study were:
1) to develop means of identifying the immature stages of
the known insect predators and parasites of the Douglas-fir beetle; 2) to investigate the possible distribution,
spatially and/or temporal, of the known insect predators
and parasites in standing trees infested by the Douglas-fir...
The objectives of this study were: 1) to learn the life history and habits of Medetera aldrichii Wheeler and a Lonchaea sp. in association with the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, in western Oregon and Washington; 2) to determine if the larvae of M. aldrichii were predaceous on the Douglas-fir...
Three coleopterous predators associated with the Douglas-fir
beetle (Dendroctonus pseudotsugae Hopkins in a second growth
forest of Douglas-fir (Pseudotsugae menziesii (Mirb. ) Franco)
in western Oregon are Enoclerus sphegeus Fabriciup, E, lecontei
Wolcott, and Thanasirnus undatulus Say. A study was undertaken
with the following objectives: (1) to determine the diurnal...
Oxygen uptakes of Douglas-fir beetles collected during November
1969 through April 1970 were measured at different experimental temperatures.
The oxygen uptakes of adult beetles increased at each
experimental temperature as the seasons progressed from winter to
spring.
The larval and pupal Douglas-fir beetles, collected in February
1970, had lower oxygen...
The effect of competition on the brood survival of the Douglas fir
beetle Dendroctonus pseudotsugae Hopkins, in down or windthrown
Douglas-fir Pseudotsuga menziesii (Mirb.) Franco was studied in the
field and the laboratory. The investigation of the role of competition
in the population dynamics of the beetle had four objectives:...
The study was undertaken to determine the seasonal and diurnal
flight patterns of scolytid beetles inhabiting a second growth
forest of Douglas-fir (Pseudotsuga menziesii (Mirb.)Franco) in western
Oregon. Air temperatures, relative humidity, light intensity, and wind
velocities were recorded for evaluation of their influence on flight activity.
The insects were...
Six species of Cleridae, including Enoclerus spegeus Fabricius,
E. lecontei Wolcott, E. schaefferi (Barr), E. eximius Mannerheim,
Thanasimus undatulus Say, and an undescribed species of Enoclerus,
were found on Douglas-fir in western Oregon. E. sphegeus was the
only clerid of the six species studied which was primarily associated
with the...
The Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) can kill large numbers of Douglas-fir trees (Pseudotsuga menziesii (Mirbel) Franco) across a landscape during periods of population outbreaks. High-value individual trees and small stands can be protected from Douglas-fir beetle infestation during outbreaks by applying the anti-aggregation pheromone, MCH (3-methylcyclohex-2-en-1-one). MCH treatments are...