Maternal and paternal influences on mating frequency in harvester ants

Abstract

Multiple mating by females is taxonomically widespread and intensively studied from the perspective of why females mate with many males. In many multiply mating species, females can vary substantially in mating frequency, but the causes of this variation are not well understood. We used directed mating to explore the causes of variation in mating frequency in a harvester ant whose queens mate an average of 10 times but where naturally occurring mating frequency ranges from 2 to 15 mates. Matrilines differed in mating frequency and especially in their probability of mating with the first male lineage that they encountered. Differences in matriline mating frequency were not related to differences in female size among matrilines. Male mating success was not correlated with the order in which males encountered females, suggesting that male success may depend on which matrilines they encounter. Our results suggest that variation in mating frequency may be a consequence of differences among matrilines due to additive genetic and/or maternal effects, as has been found in other species.