The mating system and parental behaviour of the green June beetle (Cotinis nitida Linnaeus) (Coleoptera: Scarabaeidae) are exploited by avian predators

Abstract

Males of the green June beetle (Cotinis nitida) search for females emerging from lawns. Upon detecting the female sex pheromone, a male will eventually drop down close to his potential mate. He then walks rapidly through the grass until he locates the female at which time he mounts his partner. If two or more males arrive more or less simultaneously, the first male to reach the female becomes her mate. The fight pattern of searching males makes them vulnerable to predatory common grackles (Quiscalus quiscala) and blue jays (Cyanocitta cristata), which attack flying or recently landed beetles. Later in the flight season, females flying low in a search for oviposition sites in the lawn are also targeted by grackles and blue jays, demonstrating that both sexually selected behaviour and naturally selected parental behaviour carry fitness costs for green June beetles.