ABSTRACT
This chapter presents the mating systems of two temperate congeners in the genus Rhagoletis to identify selection pressures that might have influenced the evolution of important differences in their mating systems. Some researchers have hypothesized that oviposition site guarding occurs in walnut husk fly, as well, because males are often found in the vicinity of oviposition wounds on developing walnuts. Fruit with apple maggot fly (AMF) host marking pheromone also contain egg(s) from previous females, but it is not likely that these males are ‘‘guarding” oviposition sites since female AMF avoid superparasitism. In other species of Rhagoletis flies that infest walnuts, studies have indicated that males guard oviposition punctures presumably to gain access to females for mating and possibly to protect investments in offspring.
