Search results for "British Columbia"
showing 4 items of 4 documents
Lipid-containing semipermeable membrane devices (SPMDs) as concentrators of toxic chemicals in the lower Fraser River, Vancouver, British Columbia.
1998
Abstract Semipermeable membrane devices (SPMDs) were deployed in the water column and in the sediments of the Lower Fraser River (B.C., Canada) to compare the levels and the congener profiles of polychlorinated dibenzo- p -dioxins (PCDDs), dibenzofurans (PCDFs) and non- ortho -chlorinated biphenyls (N-o,o′-PCBs) against those sampled by an Infiltrex resin column water sampler. Also the relationship between what was present in the ecosystem as sampled by SPMDs and what was accumulated in the tissue of resident benthic-feeding fish was explored. Only the lipid portion of the SPMDs was prepared for analysis, due to some technical difficulties in cleaning the polyethene tubing. The calculated w…
Parasitoids of Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) recovered in western North America and first record of its egg parasitoid …
2012
The parasitoid complex of the western conifer seed bug, Leptoglossus occidentalis, was studied in British Columbia and California on Pinus monticola and P. contorta var. latifolia. Three egg-parasitoid species were identified: Gryon pennsylvanicum (Hymenoptera: Platygastridae), Ooencyrtus johnsoni (Hymenoptera: Encyrtidae) and Anastatus pearsalli (Hymenoptera: Eupelmidae). Leptoglossus occidentalis represents a new host record for O. johnsoni, and California is a new distribution record for G. pennsylvanicum. Gryon pennsylvanicum was the dominant species during the entire oviposition period of the bug, reaching peak parasitization levels in July (25%). Ooencyrtus johnsoni and A. pearsalli e…
Cuticular hydrocarbons of Drosophila montana: geographic variation, sexual dimorphism and potential roles as pheromones.
2014
Abstract Sexual selection within populations can play an important role in speciation when divergence in mating signals and their corresponding preferences occur along different coevolutionary trajectories in different populations. In insects, one potential target of sexual selection is the blend of cuticular hydrocarbons (CHCs), which often show intra- and interspecific variation, sexual dimorphism and may act as pheromones. In Drosophila montana, a cold-adapted, circumboreal member of the Drosophila virilis species group, flies from different populations have been found to show significant premating isolation as well as variation in male mating signal (song) and female preference. While t…
The Nanaimo Free Press [Tuesday, May 17, 1921]
1921
https://viurrspace.ca/bitstream/handle/10613/12513/May17-1921.pdf?sequence=2&isAllowed=y