Effects of female mating status on copulation behaviour and sperm expenditure in the freshwater crayfish <Emphasis Type="Italic">Austropotamobius italicus</Emphasis>

Sperm competition models predict that males should adjust their sperm expenditure according to the risk and/or intensity of sperm competition. In this paper, we analysed copulatory behaviour of both sexes and sperm expenditure in relation to female mating status (virgin or mated) in the freshwater crayfish Austropotamobius italicus, a species where males have been reported to feed on and remove sperm laid by other males. The same females were allowed to be inseminated sequentially by two males, and we compared the sexual behaviours of partners between the first (virgin females) and the second mating (mated females). We found that female resistance did not differ between the first and the second mating, nor males refused or took more time to mount a mated female. However, when mating with a mated female, males reached an effective copulation position significantly later. This occurred because second-mating males removed, by eating, all or most spermatophores previously deposited by first males. As removal was often incomplete, this resulted in a larger amount of sperm being deposited on female ventral parts after the second mating, although second males did not allocate more sperm to mated females than first males did. Thus, the peculiar mode of sperm competition, where males remove previously deposited sperm, and the consequent predictable strong last male prevalence in paternity likely led to the observed lack of adjustment of sperm expenditure to female mating status in this species.     

Unattractiveness of mated females to males in the parasitoid wasp Spalangia endius

Despite common stereotypes, males are not always indiscriminate and eager when it comes to mating. In the parasitoid wasp Spalangia endius, the initial response of males to females was almost always one of apparent excitement; however, this was followed by a clear preference for virgin females over mated females in both no-choice and choice situations. The no-choice data were collected from videotapes of male-female pairs of all possible combinations of mated and virgin individuals. Neither female nor male mating status had a significant effect on likelihood of, or time until, contact or male courtship fanning. However, a males first retreat was sooner when the female was mated than when she was virgin; mated males exhibited their first retreat sooner than did virgin males; and mated females were less likely to be mounted than were virgin females. In addition to the videotapes, male-choice experiments were performed. When given a choice of a virgin and a mated female, both virgin and mated males were more likely to mount and copulate with the virgin. The difference in response to virgin versus mated females seemed to be less in virgin males than in mated males, perhaps due to virgin males greater eagerness to mate: when a virgin male and a mated male were presented with a dead virgin female, the virgin male was usually the first to respond to the female. That males preferentially retreated from and avoided mounting mated females appears to be adaptive given that mated females rarely copulated.Communicated by N. Wedell     

Sperm competition and evidence of sperm fertilization patterns in the carrion ball-roller beetle Canthon cyanellus cyanellus LeConte (Scarabaeidae: Scarabaeinae)

Field observation and laboratory experiments were conducted to investigate sperm competition and patterns of sperm fertilization under different experimental conditions in the carrion ball-roller beetle Canthon cyanellus cyanellus. Males in nature can mate with females whose spermathecae contains fertile sperm from other males. Sperm precedence was investigated using a visible genetic marker. The progeny of red (homozygous recessive) virgin females mated once with a red male and afterward, once with a green beetle (homozygous dominant) and vice versa, revealed that regardless of its color, the last male to mate fertilized c.a. 50% of the eggs, suggesting strong sperm competition. Males were able to achieve higher levels of paternity (more than 80%) when mated ad libitum with previously mated females, although large amount of variance in paternity does not exclude the possibility of first male sperm precedence or female cryptic choice. These results suggest that repeated mating and sperm replacement are the mechanisms by which last males achieve sperm precedence.     

Mate guarding,copulation strategies and paternity in the sex-role reversed,socially polyandrous red-necked phalarope<Emphasis Type="Italic"> Phalaropus lobatus</Emphasis>

In a recent review, Westneat and Stewart (2003) compiled evidence that extra-pair paternity results from a three-player interaction in which sexual conflict is a potent force. Sequentially polyandrous species of birds appear to fit this idea well. Earlier breeding males may attempt to use sperm storage by females to obtain paternity in their mates subsequent clutches. Later-breeding males may consequently attempt to avoid sperm competition by preferring to pair with previously unmated females. Females may bias events one way or the other. We examined the applicability of these hypotheses by studying mating behavior and paternity in red-necked phalaropes (Phalaropus lobatus), a sex-role reversed, socially polyandrous shorebird. Male red-necked phalaropes guarded mates more strongly than other shorebirds. Males increased within-pair copulation attempts during their mates fertile period, and maintained or further increased attempts towards the end of laying, suggesting an attempt to fertilize the females next clutch; these attempts were usually thwarted by the female. Paired males sought extra-pair copulations with females about to re-enter the breeding pool. Multilocus DNA fingerprinting showed that 6% of clutches (4/63) each contained one chick sired by a male other than the incubator, producing a population rate of these events of 1.7% (n=226 chicks). Male mates had full paternity in all first clutches (n=25) and 15 of 16 monogamous replacement clutches. In contrast, 3 of 6 clutches of second males contained extra-pair young likely fathered by the females previous mate. Previously mated female phalaropes may employ counter-strategies that prevent later mating males from discriminating against them. The stability of this polyandrous system, in which males provide all parental care, ultimately may depend on females providing males with eggs containing primarily genes of the incubating male, and not a previous mate.Communicated by M. Webster     

Costs of courtship and mating in a sexually cannibalistic orb-web spider: female mating strategies and their consequences for males

The costs of courtship and mating may include increased risks of predation, the transmission of pathogens, and a loss of foraging opportunities. Thus, a female's decision to tolerate a courting male will depend upon how these costs offset the benefits of mating, which will depend on her reproductive and nutritional status. While these costs may be similar for mated and unmated females, the benefits of mating will be less for mated than virgin females. However, the cost of lost foraging opportunities may be higher for females with fewer nutritional reserves necessary for forming eggs. We examined how these costs and benefits influence the courtship and mating behaviour of male and female orb-web spiders, Argiope keyserlingi. In the field, females on webs that also contained a courting male intercepted fewer prey items per hour than females on webs without a male. In the laboratory, the presence of a courting male at the hub also attracted mantid predators to the web, increasing the risk of predation for both male and female. Staged mating experiments in the laboratory revealed that the frequency of female attacks and pre-copulatory cannibalism was greater among mated than virgin females. Feeding history did not affect aggression in virgin females but, among mated females, food-deprived spiders attacked and cannibalized males more frequently than sated females and only the latter ever remated. These differences in female behaviour influenced male mating strategies. Choice experiments demonstrated that males preferred to venture onto the silk threads of virgin rather than those of mated females. Similar patterns of mate selectivity were observed in the field; females with narrow abdomens attracted more males to the webs than females with broad abdomens, and copulations were observed more frequently among females with narrow abdomens. These smaller females are likely to be virgins that have recently molted. Males that preferentially mate with virgin females will not only avoid potentially fatal attacks but also obtain, on average, a higher fertilization success.     

A female preference for experienced males in the almond moth, Cadra cautella

Male mating status can affect female reproductive output if male ejaculate investment declines over consecutive matings. Accordingly, females are predicted to mate preferentially with virgin males. In mildly polyandrous lepidopterans, female fitness is less affected by reduced male investment than in more polyandrous species, and so the predictions for female mating preferences are less clear. We examined female mating preferences in the mildly polyandrous almond moth, Cadra cautella, in which ejaculate size does not affect female reproductive output. First, we allowed females to mate with virgin or once-mated males, in which the males were presented individually or simultaneously. We recorded the latency to mating and, in the case of the simultaneously presented trials, the identity of the successful, copulating male. We found that females mated more frequently with mated males (when simultaneously presented with both males), yet females did not differ in the time taken to initiate copulation with any male. We further examined if this mated male advantage was due to differential mate detection or locomotory behaviour of the male treatments. We tested the ability of virgin and mated males to locate a receptive female within a wind tunnel using long-distance pheromone cues and recorded their activity budget. We found no difference in the ability of mated or virgin males to locate or approach a receptive female, or in their activity levels. These data suggest a female preference for mated males in this species, a preference that may minimise other potential costs of mating.     

Genetic analysis of parentage within experimental populations of a male dimorphic beetle,<Emphasis Type="Italic"> Onthophagus taurus</Emphasis>, using amplified fragment length polymorphism

We used the multilocus DNA fingerprinting technique, amplified fragment length polymorphism, to examine parentage of 902 offspring from eight experimental populations of the dung beetle, Onthophagus taurus. The males of this species exhibit a suit of morphological and behavioural traits that characterise alternative mating tactics. Hornless minor males sneak copulations with females that are guarded by horned major males. Our aims were to provide a prospective assessment of the potential role of frequency dependence in the maintenance of alternative mating tactics, to assess the levels of polyandry, and to determine the patterns of sperm usage by multiply mated females. The average proportion of offspring sired by major and minor males did not co-vary with the relative frequency of each morph present in experimental populations. However, there was some indication that the effective mating frequency (number of females producing offspring sired by a given male) of major and minor males may exhibit frequency dependence. Mating success of both male types declined with increasing numbers of major males. Paternity was positively associated with effective mating frequency. Females produced offspring sired from between one and eight males and, on average, paternity was distributed equally amongst a females mates, regardless of the number of males mated. Differences in fertilisation success among males were not associated with alternative male phenotypes. Neither did a males fertilisation success depend on his genetic dissimilarity with the female. These results are discussed in the context of the evolution of alternative mating strategies, and mechanisms of postcopulatory sexual selection.Communicated by N. Wedell     

Why do male Callosobruchus maculatus beetles inseminate so many sperm?

Male Callosobruchus maculatus F. (Coleoptera: Bruchidae) inseminate more sperm than females can effectively store in their spermathecae. This study examines the adaptive significance of excess sperm transfer by measuring components of male and female reproductive success in response to manipulating the number of sperm inseminated. The number of sperm transferred during copulation was reduced from 56,000 ±4,462 to 8,700±1,194 by sequentially mating males to virgin females. Reducing the number of sperm inseminated by the first male to mate had no effect on the extent of sperm precedence, but reducing the number of sperm inseminated by the second male resulted in a significant reduction in the extent of sperm precedence. When large numbers of sperm are inseminated the remating refractory period of females is increased. These results indicate that males transferring large numbers of sperm during copulation have a two-fold advantage at fertilization; they are more effective at preempting previously stored sperm and they are likely to father more offspring by delaying the time of female remating. The transfer of excess sperm does not appear to serve as nonpromiscuous male mating effort; the number of eggs laid, their fertility and the subsequent survival of zygotes were unaffected by manipulating the number of sperm inseminated. The underlying mechanisms of sperm precedence were also examined. Simple models of sperm displacement failed to accurately predict the patterns of sperm precedence observed in this species. However, the results do not provide conclusive evidence against the models but rather serve to highlight our limited understanding of the movement of sperm within the female's reproductive tract.     

Sperm competition in the mite Caloglyphus berlesei

Summary The sperm utilisation pattern of C. berlesei was investigated using the sterile male method. The last male to mate with a female fertilised most of her eggs. In experiments where females mated with two virgin males, second males fertilised on average 86% of eggs when second matings took place immediately after the first. Last male sperm priority was also confirmed in experiments where females mated sequentially with three males. The proportion of eggs fertilised by the second male decreased to 71% and 56% when the interval between matings was 2 and 6 h, respectively. Males that had opportunities to mate prior to experiments copulated for a shorter time than virgin males, and second males fertilised on average 74% eggs.     

Paternity assurance by “helpful” males: adaptations to sperm competition in burying beetles

Summary Male burying beetles invest parentally by participating in the burial of a carcass and in provisioning and guarding the larvae that come to the carcass. Since most of the females arriving at a carcass have stored fertile sperm within their spermathecae, sperm transferred by such helpful males must compete with other males' ejaculates for the fertilization of the female's eggs. We showed that these males are able to achieve a high level of paternity (mean=92%). The mechanism they employ is a repeat-mating tactic, i.e., the female is mated very frequently shortly before and during oviposition. Repeated matings are essential for a high reliability of paternity, since single copulations result in the fertilization of only a very small proportion of the female's eggs.     

Roles of interplant movement,acoustic communication,and phototaxis in mate-location behavior of the leafhopper Graminella nigrifrons

Summary Male Graminella nigrifrons leafhoppers (Cicadellidae: Homoptera) employ a call-fly strategy to find virgin females on oat host plants. Males observed in isolation during daylight hours exhibit a high rate of interplant movement, calling from the lower canopy on each plant visited. Virgin and mated females exhibit little interplant movement. They differ from one another in that virgin females perch on the upper half of plants, whereas mated females perch on the lower half of plants. The positioning of females in the plant canopy is influenced by light. Unlike mated females, virgin females respond to male calls by emitting their own acoustic signals. When virgin females are present on plants visited by males, interplant movement of males ceases, and a localized-upward search of the female bearing plant ensues. Male search is influenced by light. Regardless of whether virgin females were confined to the upper or lower portion of plants, direction of male search was towards a light source used to illuminate above or below the plant canopy. These findings suggest that interplant movement by males and sedentary behavior by females prior to mate recognition and their use of acoustic and phototactic sensory modalities after mate recognition represent previously unrecognized adaptations to problems associated with the use of vibrational signals on plants. Offprint requests to: R.E. Hunt at the current address     

Sperm competition and the level of polyandry in a bushcricket with large nuptial gifts

Variation in paternity due to sperm competition or post-copulatory female choice has a major influence on animal mating system evolution and on the levels of genetic variability in natural populations. However, there are relatively few studies comparing the outcome of sperm-competition experiments in the laboratory with natural variation in polyandry among families from the field. In the bushcricket Ephippiger ephippiger, females mate multiply, and the males provide them with a large, nutritious, and probably expensive, donation at mating. We examined paternity in a series of laboratory matings, where females mated with two males, and amongst a series of families collected from a natural population. In the laboratory, paternity was highly bimodally distributed: 24% of families had offspring fathered by the first male to mate, 68% by the second male (in only 8% was paternity shared). In the field, paternity was more mixed: only 27% of families had a single father, 14% had more than two fathers, whilst 59% had two fathers. While unsuccessful matings may contribute to the highly biased paternity in the laboratory, they cannot fully explain the high incidence of complete P2 families. Nonrandom sperm utilisation is therefore likely. Greater sperm mixing in the field probably results from females mating with more males, but the distribution of paternity also reflects an active process of nonrandom sperm utilisation. Confidence of paternity due to last male advantage may be relatively high in this species, and therefore may have facilitated the evolution of the large spermatophore in E. ephippiger.Communicated by D. Gwynne     

Female-enhanced male competition determines the first mate and principal sire in the spider Linyphia litigiosa (Linyphiidae)

Summary Two to five days before sexual maturation, female sierra dome spiders (Linyphia litigiosa: Linyphiidae) undergo a transformation in their behavior toward males that visit their webs. During this latter part of their penultimate instar, females change from consistently positioning themselves far away from males to actively maintaining close proximity, reactions I call avoidant and associative behavior, respectively. Consistent associative behavior ceases after the female's first mating and thus is limited to soon-to-mature penultimate females. When a mate-seeking male fords an associative female, he attempts to guard her until she matures; this is often a multi-day affair. In contrast, males guard immature avoidant and mature mated females for only a single day. This dichotomy in male guarding times can be understood by the fact that associative behavior signals that the female will soon develop peak reproductive value. Upon completion of their final molt, 98% of females immediately mate with the current guarding male. Secondary suitors are not as likely to achieve mating. Moreover, first mates father 1.8 times more offspring, on average, than secondary mates. Whenever they meet on any female's web, males fight until one of the contestants withdraws. Fights typically are intensive, occasionally deadly, and often result in usurpation of the web by the newly arriving male. Larger males win more fights, but other qualities (e.g., vigor and persistence) appear to be important when contestants differ by less than 10–20% in body weight. Prolonged (i.e., multi-day) guarding of associative females enhances the intrasexual selection process by ensuring that every male that arrives at the web finds it already guarded. Therefore every male that finds the web becomes a participant in a series of male-male conflicts and web usurpations which span the period between the resident female's commencement of associative behavior and her sexual maturation. Since unforced male departures from the webs of associative females are rare, victors are retained on the web until they themselves lose a fight. This facilitates a steady increase in the fighting ability of sequential guards throughout the associative period, up until female maturation and mating. On my study site, first mates represented the final winners in a combative sorting process based on a minimum average of 2 fights; they were heavier and larger than secondary mates and randomly sampled males. The combination of (1) associative behavior by nearly mature females, (2) high mating propensity of newly mature females, and (3) first male sperm priority, constitutes a system whereby females enhance male-male competition and boost the expected fighting prowess of the principal sire of their progeny. Since males appear to make no material contribution toward progeny, the female's behavior probably functions to improve the genetic constitution of the offspring. In addition, the timing of associative behavior may limit prolonged guarding by food-stealing males to a period (1) encompassing the female's pre-molt fast and (2) before the heavy yolking of eggs, thereby ameliorating the nutritional costs of intrasexual selection.     

Proximal traits and mechanisms for biasing paternity in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae)

A comprehensive understanding of sexual selection requires knowledge of the traits and mechanisms responsible for increasing a male’s paternity share (proportion of progeny sired) relative to that of other males mating with the same female. In this study we manipulated by starvation the expression of traits that might influence male paternity share in Tribolium castaneum. We then conducted experiments to examine how male starvation affects male performance during sequential episodes of sexual selection from mating to progeny production, and investigated female control over specific stages by using live vs dead females. Comparison of starved vs fed males revealed that T. castaneum females have control over spermatophore transfer during mating, as live females rejected inseminations by starved (“low quality”) males. None of the measured male copulatory behaviors (leg-rubbing frequency, asymmetry, and percent of time spent rubbing) affected the probability of successful insemination, but the last two were positively associated with male paternity share. Spermatophore positioning within the female reproductive tract was not affected by male treatment (starved/fed), by female treatment (live/dead), or by male copulatory behaviors. Starvation, however, had a dramatic effect on male reproductive physiology, decreasing both accessory gland size and total number of sperms transferred (but not sperm viability in seminal vesicles). In addition, females who mated to starved males stored fewer sperms in their spermathecae, which, together with decreased ejaculate size, may explain the reduced paternity share of starved males compared to fed males. This study elucidates some cryptic mechanisms influencing male reproductive success and aids our understanding of trait evolution through sexual selection.     

Female fitness, sperm traits and patterns of paternity in an Australian polyandrous mouse

Multiple mating is a common reproductive strategy among mammals, and rodents living in communal, mixed sex social groups are predisposed to a polygamous existence. The sandy inland mouse is a naturally polyandrous species that occurs across most of Australia’s arid region. Females typically have greater reproductive restrictions compared with males and are therefore expected to acquire substantial fitness benefits from copulating with more than one male. Here, I show that the reproductive output of female sandy inland mice did not differ between females mated monandrously (single male) or polyandrously (two males). Paternity data obtained from the polyandrous litters revealed that in most cases, there was a first male-to-mate advantage. I discuss this result in relation to the chastity enforcement hypothesis for the evolution of the copulatory plug. Finally, I compared ejaculate traits of competing males and found that the paternity loss of males that mated first was attributable to their own sperm density and sperm quality, and not to that of their rivals. The sperm data also revealed that second males gained greater paternity representation when sperm velocities and motilities were higher in first-mated males. This investigation indicates that mating position is a critical determinant of male fitness in mammalian sperm competition.     

Copulation duration and sperm precedence in the stalk-eyed fly Cyrtodiopsis whitei (Diptera : Diopsidae)

Summary By means of field observations and laboratory experiments on the Malaysian stalk-eyed fly Cyrtodiopsis whitei we examined the consequences of variation in copulation duration for sperm competition. In this sexually dimorphic species over 90% of all copulations occur in nocturnal aggregations with from one to four males and up to 24 females. Copulation duration observed in both the field and the laboratory exhibited a bimodal distribution with peaks at 10 and 50 s. In the field short copulations less than 30 s long occurred frequently when more than one male was present in an aggregation but most were not the direct result of male interference. Sperm counts from female spermathecae after artificial interruptions indicated sperm are not transferred during the first 40 s of a copulation. When solitary males mated up to five times in succession to virgin females, short copulations did not occur, nor was the number of sperm transferred reduced. However, short copulations did occur when we mated isolated females within 6 min of a previous copulation. By mating irradiated and non-irradiated males in reciprocal pairs we discovered that C. whitei exhibits both first-male sperm precedence and sperm mixing. More than half of the females mated first to sterile and then to fertile males failed to produce offspring. Such variation in copulation duration and sperm precedence is consistent with male placement and detection of a spermatophore that acts as a temporary mating plug. Our data suggest that those male C. whitei which successfully defend large aggregations of females reduce sperm waste and competition by preferentially transferring sperm to females that have not mated recently. Correspondence to: G.S. Wilkinson     

Influence of mating order on courtship displays and stored sperm utilization in Hermann's tortoises (Testudo hermanni hermanni)

Sperm storage is widespread in many vertebrate groups, and it is frequently associated with promiscuous mating systems. Chelonian species are one of the most outstanding examples of a promiscuous group capable of long-term sperm storage; specialized structures have evolved within the oviducts of these vertebrates to ensure sperm vitality across reproductive cycles. Thus far, few studies have investigated the factors regulating multiple paternity, sperm usage by females and paternity distribution in successive clutches. This study aimed to investigate the effect of mating order on male mounting and reproductive success in Testudo hermanni hermanni, combining behavioural and genetic data. A series of planned matings were performed, within which experimental females were mated sequentially to two different males under controlled conditions. Observations conducted during experimental matings revealed that courtship displays did not significantly differ between the first and second males to mate with a female. Interactions ending with a mount were characterized by a significantly higher intensity and occurrence of determinate courtship behaviours, for example biting and running after the female. Paternity analysis performed on hatchlings produced from experimental females revealed that 46 % of the clutches were multi-sired. A significant contribution of previous years' partners was still found, thus confirming the long-term sperm storage within the female oviduct in this species. Finally, mating order did not significantly affect the reproductive success of experimental males during the on-going reproductive season.     

Polyandrous female butterflies forage for matings

Butterfly mating systems exhibit great variation and range from strict monandry to strong polyandry. During mating males transfer ejaculates containing both sperm and accessory substances to females. In the polyandrous green-veined white butterfly, Pieris napi (Lepidoptera, Pieridae) these ejaculates average 15% of male body mass, but can represent up to 23% of body mass for individual males. Hence, mating is costly to males, and recently mated males increase copula duration but decrease ejaculate mass transferred to females. Substances transferred to females during mating are later incorporated into female soma and reproductive tissues, and multiply mated female butterflies have higher lifetime fecundity, lay proportionately larger eggs, and live longer compared to once mated females. Here we report that females of P. napi allowed to mate at liberty with recently mated males only (i.e. males that delivered a small ejaculate) increased their lifetime number of matings compared to females allowed to mate with virgin males only (i.e. males that delivered large ejaculates), the former group mating on average 5.1 times (range 2–10) and the latter group mating on average 2.8 times (range 1–4). The lifetime fecundity of the two groups of females did not differ significantly. Because nutrient donation from males is essential for females to realize their potential fecundity, we conclude that females of the polyandrous green-veined white actively forage for matings.     

Ectomised conductors in the golden orb-web spider, Nephila plumipes (Araneoidea): a male adaptation to sexual conflict?

Male genitalia may facilitate sperm protection by acting as a plug that prevents or hinders future matings. The pedipalps (intromittant organs) of males of the orb-web spider, Nephila plumipes, have a conductor with a peculiarly curved ending and a triangular process near the terminal end. The tip of the conductor, including the process, breaks during most matings and remains inside the female genital tract. We explored the possible function of the conductor as a mating plug using the double-mating sterile-male technique. Our data are not consistent with a plug function because males use only one pedipalp in each mating, thus leaving an unobstructed insemination duct available for future matings; conductors of males mating with virgin females are not more likely to break than those of males mating with mated females, and second males show no preference for used or unused spermathecae. In addition, males that inserted their palp in the insemination duct that contained a tip of the conductor from a previous male obtained a share in the paternity of the female's clutch of eggs. Interestingly, the conductor is more likely to break if it is inserted in an unused spermatheca. We argue that several lines of evidence suggest that the conductor breaks as a result of intersexual conflict over the duration of copulation.     

Male remating and female fitness in the wolf spider Pardosa astrigera: the role of male mating history

Although the effects of male mating history on female reproductive output and longevity have been studied in insects, few such studies have been carried out in spiders. In a mating system in which females are monandrous while males are polygynous, females may incur the risk by mating with successful males that have experienced consecutive matings and suffer from the possible depletion of sperm and/or associated ejaculates. Here, we examine the effects of male mating history on male courtship and copulation duration, female reproductive fitness, and female adult longevity of the wolf spider, Pardosa astrigera. Results indicated that male mating frequency had little effect on their subsequent copulation success, and of 35 males tested, about half of the males were able to copulate with five virgin females successively at an interval of 24 h. Male mating history had little effect on their courtship duration. However, male mating history significantly affected male copulation duration, female adult longevity, and reproductive output. Males that mated more frequently copulated longer and more likely failed to cause their mates to produce a clutch, although there was no significant difference in the number of eggs laid and the number of eggs hatched regardless of the first clutch or the second one. Multiple mating of male P. astrigera resulted in significant reduction in female adult longevity. Our results indicate that monandrous females mating with multiple-mated males may incur substantial fitness costs.