You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Population Densities of Spiders (Araneae) and Spruce Budworms (Lepidoptera, Tortricidae) on Foliage of Balsam Fir and Red Spruce in East-Central Maine
Daniel T. Jennings, John B. Dimond and Bruce A. Watt
The Journal of Arachnology
Vol. 18, No. 2 (Summer, 1990), pp. 181-193
Published by: American Arachnological Society
Stable URL: http://www.jstor.org/stable/3705836
Page Count: 13
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Spiders of 10 families, 17 genera, and at least 22 species were collected from crown foliage samples of Abies balsamea (L.) Mill. and Picea rubens Sarg. in east-central Maine. Species of web spinners were more prevalent (68.2% of total species) among branch samples (N = 613 branches) than species of hunters (31.8%). Mean species per site (N = 8 sites) was 7.6 ± 1.2. Numbers, life stages, and sex ratios of spiders differed between tree species; sex ratios were biased (G-test, P ≤ 0.001) in favor of females. Spider densities per m2 of foliage area generally were greater (P ≤ 0.05) on red spruce (X̄ = 12.0 ± 1.3) than on balsam fir (X̄ = 7.2 ± 0.9), but sampling intensity was important. For intensely sampled sites, overall mean densities of spruce budworms / m2 of foliage were not significantly different (P > 0.05) between tree species. Spearman's rank correlation coefficients indicated that spider-budworm densities covaried weakly among study sites for each tree species; balsam fir ((rho) = 0.17, N = 343), red spruce ((rho) = 0.15, N = 270). Enhancement of spider populations through silvicultural treatments designed to favor spruces is proposed.
The Journal of Arachnology © 1990 American Arachnological Society