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...
Factors considered were phloem moisture, sour-phloem (which
may be furthered by the presence of ample phloem moisture), oleoresin of the host, and the presence of unmated female beetles in
suitable host material.
Levels of phloem moisture present in variously prepared logs
in the field ranged from about 100 to upwards...
The bionomics of Medetera aldrichii Wheeler (Diptera:
Dolichopodidae), a predator of the Douglas-fir beetle (Dendroctonus
pseudotsugae Hopkins (Coleoptera:Scolytidae)), was investigated
in western Oregon.
The predator pupated in host galleries proximal to bark beetle
ventilation holes. The tendency of prepupal larvae to form pupal
cells near illuminated areas in a photo-response...
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...
The flight behavior of Ips confusus (Lec.) was primarily
studied under field conditions, but augmented with
complementary laboratory studies whenever feasible. The
experiments were mostly conducted in areas of endemic population
levels, but also under epidemic and prairie conditions.
The techniques and devices used in marking, releasing,
attracting, and trapping...