TY - JOUR
T1 - Temporal Variation in Male Copulatory Behaviour in the Solitary Bee Nomadopsis Puellae (Hymenoptera: Andrenidae)
AU - Rutowski, R. L.
AU - Alcock, J.
N1 - Funding Information:
METHODS The bees were observed from 8 to 27 April 1976 and from 28 March to 19 April 1978 at the Blue Point Campground area on the Salt River in central Arizona. The study site is north of Mesa, Arizona, about 0.5 km downstream from Stewart Mountain Dam. Vegetation typical of riparian habitats in the Sonora Desert predominates in this region, 1) This study was supported by National Science Foundation Grant No. DEB76-04503-A01 to ALCOCKO. ur thanks to Mbida MPOAMEfo r translating the summary. especially mesquite (Prosopiss p.) and palo verde (Cercidium floridumBe nth). In the spring of 1976 and 1978 (but not in the intervening year), the desert dandelion (Malacothrixg labrata Gray) appeared of N. in scattered patches throughout the study area (Fig. 1B). This is the primary foodplant puellae.
PY - 1980
Y1 - 1980
N2 - 1. Females of the solitary bee, Nomadopsis puellae, foraging for pollen at flowers will copulate with any male that can reach them but the duration of copulation is not constant over the daily foraging-mating period (which lasts from about 0900-1300). Early on, copulations are brief (usually less than 1 min). As the morning progresses, males tend not to release their mates spontaneously but remain in copula for as long as it takes a female to collect a full pollen load and return to her nest. In addition, late in the mating period males that have not secured a single female may begin to assault pairs in attempts to usurp a female from a copulating male. 2. We propose that males control the duration of mating in ways that reflect a change in the genetic gains associated with brief versus prolonged copulations over the course of the morning. We assume that sperm precedence occurs in this species and that females are more likely to oviposit at the end of the foraging period than at the beginning. If these assumptions are correct, guarding a mate through prolonged copulation could become increasingly advantageous as the mating period draws to a close each day. Given a high degree of competition for mates, a male that secured a female on her last trip of the morning could greatly improve the chance that his mate would use his sperm for fertilization if he prevented other males from reaching her until she was safely back inside her nest burrow. 3. An alternative hypothesis that the variation in copulation length is due to changes in the readiness of females to receive sperm from a male over the mating period is considered. Limited data suggest that females do not signal degrees of sperm receptivity to males. Males probably determine how long they will copulate, switching from the tactic of securing many short (unguarded) copulations to a few lengthy (guarded) matings in the course of a morning.
AB - 1. Females of the solitary bee, Nomadopsis puellae, foraging for pollen at flowers will copulate with any male that can reach them but the duration of copulation is not constant over the daily foraging-mating period (which lasts from about 0900-1300). Early on, copulations are brief (usually less than 1 min). As the morning progresses, males tend not to release their mates spontaneously but remain in copula for as long as it takes a female to collect a full pollen load and return to her nest. In addition, late in the mating period males that have not secured a single female may begin to assault pairs in attempts to usurp a female from a copulating male. 2. We propose that males control the duration of mating in ways that reflect a change in the genetic gains associated with brief versus prolonged copulations over the course of the morning. We assume that sperm precedence occurs in this species and that females are more likely to oviposit at the end of the foraging period than at the beginning. If these assumptions are correct, guarding a mate through prolonged copulation could become increasingly advantageous as the mating period draws to a close each day. Given a high degree of competition for mates, a male that secured a female on her last trip of the morning could greatly improve the chance that his mate would use his sperm for fertilization if he prevented other males from reaching her until she was safely back inside her nest burrow. 3. An alternative hypothesis that the variation in copulation length is due to changes in the readiness of females to receive sperm from a male over the mating period is considered. Limited data suggest that females do not signal degrees of sperm receptivity to males. Males probably determine how long they will copulate, switching from the tactic of securing many short (unguarded) copulations to a few lengthy (guarded) matings in the course of a morning.
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U2 - 10.1163/156853980X00212
DO - 10.1163/156853980X00212
M3 - Article
AN - SCOPUS:0019090087
SN - 0005-7959
VL - 73
SP - 175
EP - 187
JO - BEHAVIOUR
JF - BEHAVIOUR
IS - 3-4
ER -