A Comparative Study of Mating Strategies in Two Species of Philanthus (Hymenoptera: Sphecidae)

Abstract

Our work on the reproductive biology of Philanthus pulcher and P. zebratus in Jackson Hole in 1980 was a continuation of a study which had three major objectives. The first was to determine the relationship between female and male activity patterns. As in other species with extensive female-contributed and no male-contributed parental investment, females are a resource necessary for reproductive success of males. Thus, the activity of females in time and space should be an important parameter affecting the evolution of male mating strategies. Our work in this area is being combined with data we have gathered elsewhere on other species of Philanthus (O'Neill and Evans, unpublished). The second objective was to determine what characteristic of males was important in determining reproductive success and the form of the mating strategy. Since our preliminary data on Philanthus indicated that body size may be the most important variable affecting male reproductive success, we concentrated on this aspect of male biology. This report will focus on our results in this area. The third objective was to determine the role of male-produced sex pheromones in the mating system. (* Erratum: pp. 56 and 57 should be 51 and 52 )