Submitted to: Pedobiologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 21, 1998
Publication Date: N/A
Interpretive Summary: Ground beetles number approximately 40,000 species worldwide, and they host a variety of agricultural pests. Ground beetles usually disperse into agricultural fields from surrounding natural habitats. Little is known about ground beetles in wheat fields and surrounding grasslands in Oklahoma. In our study, of 69 species collected, 6 species accounted for 75.5% of the total abundance. The occurrence of ground beetles was most strongly influenced by season, followed by year, and then habitat (wheat vs. grassland). Distinct groups of ground beetles were found in autumn, winter, and spring. Based on their capture location, ground beetles were classified as either habitat generalists, wheat specialists, grassland specialists, or edge specialists. Key species of ground beetles were identified that could potentially assist farmers in the natural control of pest populations in wheat. Grasslands surrounding wheat fields provide habitats important to the survival of ground beetles.
Technical Abstract: Ground beetles were captured during winter wheat-growing season in 1993- 1994 at four sites and in 1996-1997 at two sites using pitfall traps positioned in grasslands, wheat fields, and along grassland-wheat field edges. Of 69 species collected, 6 species accounted for 75.5% of the total number of beetles captured. The numbers of these species captured varied among years, seasons, and habitats. Species composition was most strongly influenced by season, followed by year, and then habitat (wheat vs. grassland). Ground beetles that reproduce in spring were separated from those producing young in autumn along the first axis of a canonical correspondence analysis (CCA). With the effects of season and year removed, ground beetles were classified with respect to habitat preference along axes one and two of a partial CCA. Based on the ordination by partial CCA, ground beetles were classified as either habitat generalists, wheat specialists, grassland specialists, or boundary specialists. Landscape structure was an important component in determining the spatial distribution of ground beetles.