Journal of the Entomological Society of British Columbia
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The aphids (Homoptera: Aphididae) of British Columbia 7. A revised host plant catalogue
Get PDFA host plant catalogue is presented for 302 species of aphids collected in British Columbia
Brachycolus asparagi Mordvilko, a new aphid pest damaging asparagus in British Columbia
Get PDFThe aphid <i>Brachycolus asparagi</i> Mordvilko was identified from asparagus at Summerland, B.C., in 1979. In 1980 and 1981, this aphid damaged asparagus throughout the asparagus-growing areas of the Okanagan as far north as Armstrong. Feeding by the aphid causes a severe rosetting of the ferns and weakens the plant
Larval head-capsule widths of Dendroctonus rufipennis (Kirby) (Coleoptera: Scolytidae)
No full textWidths of larval head capsules of <i>D. rufipennis</i> (Kirby) were measured and analysed. The frequency distribution had four distinct modes corresponding to the four larval instars. The change in mean head-capsule widths between instars showed agreement with Dyar's Rule
Siphonaptera from mammals in Alaska. Supplement IV. Revised check list for southeastern Alaska
Get PDFThe annotated check list grew to 15 taxa with the addition of <i>Opisodasys vesperalis</i> (Jordan) and <i>Chaetopsylla setosa</i> Rothschild, both new for Alaska: <i>Tarsopsylla octodecimdentata coloradensis</i> (Baker), new for southeastern Alaska; and an <i>Oropsylla</i> sp. Nine species of wild mammals and the domestic cat are reported as hosts of fleas in southeastern Alaska for the first time, increasing the total number of mammalian hosts to 25 identified species. Seventy new records for 10 islands and the mainland are combined with published records in a distribution table. Morphological variations in the posterior margin of sternum VII of females of <i>Monopsyllus ciliatus protinus</i> (Jordan) and distinguishing characters of three other taxa are illustrated
Fifty-year-old Sitka spruce plantations with a history of intense weevil attack
Get PDFThe condition of 26 plantations of Sitka spruce (<i>Picea sitchensis</i> (Bong) Carr.) established between 1930 and 1935, at Green Timbers, Surrey, British Columbia, which sustained repeated attack by the white pine weevil (<i>Pissodes strobi</i> Peck) was examined in 1981. The plantations were started either as pure Sitka spruce or as a mixture of spruce and Douglas-fir (<i>Pseudotsuga menziesii</i> (Mirb.) Franco). A detailed survey was conducted in one plantation of each type for which annual infestation levels were recorded from 1936 to 1949 and which appeared to be typical of the rest of the pure and mixed plantations.Many Sitka spruce trees were dead. having been out-competed by the other trees on the site as a result of repeated top-killing by <i>P. strobi</i>. Most surviving spruce trees were badly deformed, showed signs of severe attack, and were nonmerchantable. The plantation of pure Sitka spruce contained about 176 living Sitka spruce trees/ha, but only about 14 trees/ha were potential crop trees: the rest were suppressed or deformed. This plantation contained more volume in other volunteer conifers than in Sitka spruce. The mixed plantation developed into a merchantable stand of almost pure Douglas-fir, with only 5-6 Sitka spruce trees/ha
A test of the efficacy of immunizing cattle against Rocky Mountain wood ticks
Get PDFNine yearling steers were inoculated with an extract of <i>Dermacentor variabilis</i> (Say) suspended in aluminum hydroxide adjuvant in an attempt to increase their resistance to the feeding of <i>Dermacentor andersoni</i> Stiles. However, when these cattle were infested with <i>D. andersoni</i> ticks, there were no significant differences in the proportions of ticks feeding, or mean weights of fed ticks, in comparison with nine cattle treated with adjuvant only, or with two untreated cattle. Five of the cattle in each of the treated groups received additional ticks to test for susceptibility to tick paralysis. Three of the cattle treated with tick extract became paralysed. as did one of the cattle treated with adjuvant only. Serological responses to the immunizing antigen, assayed by indirect haemaglutination, were relatively weak. Some possible reasons for the ineffectiveness of the immunization, in contrast to earlier positive studies with guinea pigs and a few cattle, are discussed. The methods described should contribute to testing the practical efficacy of promising antigens as they are produced
Windtunnel and field observations of western spruce budworm responses to pheromone-baited traps
Get PDFFive trap designs, the Pherocon 1CP, a triangular trap, dome trap, double cone trap and Kendall trap were evaluated for capturing the western spruce budworm, <i>Choristoneura occidentalis</i> Freeman, both in a laboratory-based windtunnel and in an infested stand. Neutral density smoke tests showed the effects of orientation to wind on plume formation as well as highlighting plume structure around larger traps. Moth capture rates in the windtunnel did not always correlate with capture rates under field conditions
Erratum
Get PDFIn Vol. 80, 1983, in the article by Vernon and Houtman entitled, 'Evaluation of sprayed and granular aphicides against the European asparagus aphid...', the graphs from Figure 2 should appear above the caption of Figure 3 and vice versa
Mortality and top-kill in Douglas-fir following defoliation by the western spruce budworm in British Columbia
Get PDFSurveys of mortality and top-kill caused by the western spruce budworm, <i>Choristoneura occidentalis</i> Freeman, in 65 stands of Douglas-fir, <i>Pseudotsuga menziesii</i> (Mirb.) Franco are reported. Top-kill was detected in 85% of the stands and 25% of the trees surveyed. Mortality amounted to 8% and less than 1% of the trees examined in the Vancouver and Kamloops Forest Regions, respectively. Both frequency of top-kill and mortality were related to the number of years defoliation in the stand and were higher on suppressed trees than on dominant or co-dominant trees. Younger stands sustained a higher incidence of topkill than older stands. Tree mortality was higher on steep slopes than on flat terrain. These results suggested that top-kill or mortality were the results of physiological stress on the trees, in addition to the debilitating effects of defoliation
