Patterns of American licorice seed predation by Acanthoscelides aureolus (Horn) (Coleoptera: Bruchidae) in South Dakota

Abstract

The bruchid beetle Acanthoscelides aureolus (Horn) is a major seed predator on American licorice (Glycyrrhiza lepidota Pursh) and other legumes in North America. Mature pods of American licorice from eastern South Dakota populations were examined for seed predation by A. aureolus over a 2-year period from 1985-1986. Frequency of seed predation varied significantly between years. Percent seed predation was similar for 2-, 3-, 4-, 5-, and 6-seeded pods, indicating pods were attacked in proportion to number of seeds in the pod. Highest predation frequencies were found for seeds at the rachis end of the pod, regardless of pod size (seeds/pod). The largest seeds in pods with 4 or more seeds were from central positions while the smallest were from proximal and distal positions, suggesting beetle larvae did not select seeds on the basis of large size. When predation levels were low, seed position in the pod was more important than pod or seed size in determining frequency of seed predation by A. aureolus.