アカマダラケシキスイ成虫（コウチュウ目：ケシキスイ科）の雌雄にみられる分布様式と嗅覚反応の差異

抄録

The sap beetle, Phenolia（Lasiodites）picta（MacLeay）（Coleoptera: Nitidulidae）, is a pest that feeds on fallen Japanese apricots（Prunus mume）. Understanding the spatial distribution and migration patterns of adults should contribute to developing sophisticated management methods for this species. We counted the number of adult beetles on each fallen ripe apricot in an orchard in early summer in 2015 and 2016. Then we calculated Morisita’s I_δ index, which is an index of the distribution pattern without an association with density; it was 1.31 for females, 0.62 for males, and 1.15 for both sexes. These scores suggest that females and males have aggregated and uniform distributions, respectively. To examine if they used sexual or aggregation pheromones that can affect their distribution patterns, we tested the olfactory responses of each sex to food in plastic containers and to other individuals in a Y-tube olfactometer. Males were significantly attracted to females, while females showed a stronger response to food than to males. These results suggest that the sexual differences in the demands for food and mating partners cause the different distribution patterns in the field.