Male mate search for female emergence sites by a parasitic wasp

To evaluate the use of spatial and temporal information in dictating quantitative search patterns, we investigated the male mate-searching behaviour of a braconid wasp, Alabagrus texanus. Specifically, we asked whether these individuals use recently acquired information when establishing their use of space during searching routines. Males find virgin females by patrolling the habitat for pheromone cues, with scramble competition following. To simulate emergences, we placed just-eclosed females in fine-meshed bags that permitted pheromones to disperse. Upon presentation, male swarms formed, reaching maximum numbers within the first few minutes. Males subsequently left the swarming site, and few revisited. Females were removed after 5 min and replaced by a second female. Male numbers remained low, but when the second female was then presented 15 m away, she attracted many males. Repeating the initial experiment with a hiatus of 30 min between first and second females, the second female attracted few males, but with a hiatus of 60 min between females, the second female attracted many males. There was no increase in the number of males that responded to a second female presented closer than 5 m from that of the first female. Wasp emergence patterns revealed that more than one female seldom eclosed within a diameter of 5 m on the same day. Thus, males show short-term memory of space and time that decreases their attention to sites that are unlikely to yield a mating.