A genetic analysis of population differences in pheromone production and response between two populations of the turnip moth, Agrotis segetum

The genetic basis of the differences in female pheromone blend ratio and male behavioral response in the turnip moth, Agrotis segetum, was examined by crossing individuals derived from Scandinavian and Zimbabwean populations. These two populations differ both in the ratio of the three major female pheromone components, Z5-10:OAc, Z7-12:OAc, and Z9-14:OAc and in the behavioral response of the males in both wind-tunnel and field-trapping assays. The female pheromone blend in this study is treated as the log ng Z5-10:OAc/ng Z7-12:OAc and log ng Z9-14:OAc/ng Z7-12:OAc for statistical analysis. The mean log ng Z5-10:OAc/ng Z7-12:OAc, is under control by a major autosomal factor or factors, but it is unclear what genetic factor or factors may control the mean log ng Z9-14:OAc/ng Z7-12:OAc. Frequency distributions of the proportions of each component show wide individual variation and also suggest control of Z5-10:OAc and Z7-12:OAc by major autosomal factors, which for Z5-10:OAc may show partial dominance. Analysis of male behavioral response to synthetic blends in the wind tunnel yields inconclusive results, but suggests that A. segetum may have a broad window of response that reflects the range of individual variation in female blends.