Submitted to: Landscape Ecology Symposium
Publication Type: Proceedings
Publication Acceptance Date: March 26, 1996
Publication Date: N/A
Technical Abstract: The influences of prey abundance, within-field vegetation, and composition and diversity of the surrounding landscape matrix on communities of aphidophagous insects were studied in wheat fields in an agricultural landscape in eastern South Dakota for five years. Partial canonical correlation analysis indicated that within-field variables such as aphid abundance and crop density were important for explaining variation in the abundance of adult lady beetles (Coleoptera: Coccinellidae) in wheat fields. The density of herbaceous and grassy weeds in fields did not influence the abundance of any aphidophagous species. The proportion of cultivated land and diversity of the matrix in the section (1.5 km*2) surrounding the sampled field influenced the abundance of some aphidophagous species, especially Nabis americoferus (Carayon) (Heteroptera: Nabidae), as did the proportion of cultivated land in the eight sections immediately adjacent to the section that included the sampled field. Abundance of N. americoferus increased with the percentage of cultivated land in the matrix and decreased with increasing landscape diversity. The influence of the matrix extended beyond the eight surrounding sections and was detectable at a scale greater than 100 km*2. Results are discussed in relation to the potential for managing agricultural landscapes to promote biological control of insect pests by arthropod natural enemies.