Male mate choice based on chemical cues in the cricket Acheta domesticus (Orthoptera: Gryllidae)

1. Males in many animal species exercise mate choice to maximise their reproductive success, assessing females by characteristics related to reproductive potential, such as mating status, body size, and age. The sensory modalities involved in mate choice are often not firmly demonstrated, but only inferred. This is especially true for chemical cues and signals. 2. The present study tests whether males of the cricket Acheta domesticus are able to choose among females based only on chemosensory cues. In A. domesticus, as in many crickets, males call to attract females or roam the habitat silently to search for females. In three‐way choice trials, males were presented with two filter papers that had been placed with females for 24 h prior to the trials and one blank control. Females were either mated or virgin and starved or well‐fed. It was predicted that males would prefer virgin over mated females and those in good condition over starved ones. 3. Males were more likely to contact filters that had been exposed to females. They spent more time examining filter papers from virgin females than those from mated ones, while the condition of the females had no effect. 4. We conclude that males can detect chemical cues from females on substrate and distinguish virgin females from mated ones. Being able to assess sperm competition risk prior to mating or even before further pursuing a trail with chemical cues should confer a considerable benefit to males.     

斜纹夜蛾的性选择行为

【目的】为了解斜纹夜蛾Spodoptera litura Fabricius体重、日龄、交配经历及形态特征对其性选择行为的影响。【方法】本实验通过标记成虫后,采用观察记录的方法对其进行探究。【结果】斜纹夜蛾雌虫的体重对雄虫的性选择影响比较明显,体重较大雄虫优先选择体重较小的雌虫(71.43%),而体重较小雄虫喜欢选择体重较大的雌虫(72.00%)。体重较大和体重较小的雄虫都能获得体重较大雌虫的交配选择,但是体重较大者被选择的机会更大(70.00%),体重较小的雄虫不能获得体重较小雌虫的选择。雄虫仅选择1日龄的雌虫,而雌虫偏向选择3日龄和5日龄雄虫。交配经历影响斜纹夜蛾的性选择,未交配的雄虫优先选择未交配的雌虫(86.67%),但未交配的雌虫则优先选择已交配的雄虫(66.67%)。雄虫的形态特征(体长、翅展、腹长、复眼间距和触角长)对雌虫性选择有较明显的影响,但雌虫的形态特征除翅展的大小外,其体长、腹长、复眼间距和触角长等形态特征在雄虫选择进行交配中的作用不大。【结论】体重、日龄、交配经历及形态特征都能不同程度影响斜纹夜蛾的性选择行为。     

Female Reproductive Status and Mate Choice in the Hide Beetle, Dermestes maculatus

Models of mutual mate choice predict that when the costs of mating indiscriminately increase, so may the choosiness of the conventionally non-choosy sex. In a series of behavioral trials, we tested both male and female chemo-reception and mate choice in the hide beetle, Dermestes maculatus. Using olfactometer bioassays we found that males detected and responded more rapidly to individual mated females but had a limited ability to detect virgin females or discriminate between virgin and mated females when presented simultaneously. Both mated and virgin females were unable to detect the presence of virgin males. Copulation behaviors were comparable when males were presented with a virgin or mated female either individually or simultaneously. However, when presented simultaneously, virgin females had a higher probability of receiving a copulation than their mated counterparts. Our data show that males respond to variation in female reproductive status, but that female propensity to mate does not change. We suggest that mutual mate choice may be an important force, even in systems in which there is apparently strong selection for female mate discrimination.     

Context‐ and State‐Dependent Male Mate Choice in a Sexually Cannibalistic Spider

High male mating investment may favor selection on male mate choice particularly if females vary in quality. Terminal investment strategies constitute a maximal mating effort and have evolved independently in the absence of paternal investment in several spider taxa including the genus Argiope. To test for male mate preferences in the above context, we used the sexually cannibalistic spider A. bruennichi. We varied male state (mating status and post‐maturation age) as well as the competitive context and quantified male mate choice decisions between females of different states and developmental stages in binary choice tests. We found an overall adaptive preference for the virgin against the mated female regardless of male mating state. Furthermore, we demonstrated that older males paid more attention to female fecundity‐related traits than to mating status. In a second set of experiments, we offered males a choice between a virgin and a subadult female and varied the competitive context which had no effect on male decisions. Curiously, a preference for the virgin adult female was only apparent after exclusion of females that matured <3 d prior to the test. Repeated tests of males supported the hypothesis that males do not distinguish between a freshly matured virgin female and a subadult female. Our results show that male spiders execute mate choice based on information collected from female silk strands and that they integrate their own state into mating decisions.     

Silk‐ and volatile‐based male mate choice in the genital plug‐producing spider

Female mating history can have a strong effect on male fertilization success. Although males often prefer to mate with virgin females, they often also engage with mated females. As the intensity of sperm competition can differ among mated females, males are expected to evolve means to identify their status. In spiders, males often use female silk to gather information about female quality. Males of many spider species deposit mating plugs into female genitalia to hinder further copulations. We tested whether males of the foliage‐dwelling, plug‐producing spider Philodromus cespitum, which is an important natural enemy of pests, discriminate between females of different mating status and whether they can determine the extent of genital plugging in mated females solely on the basis of cues gained from deposited female silk. We presented males with draglines of females that varied in either mating status (virgin vs. mated), the extent of plugging (small vs. big plug), or the age of the plug (fresh vs. old plug) and examined their mate preferences. Additionally, we tested whether males were attracted to volatile cues produced by female bodies. Our experiments revealed that males preferred draglines of virgin females to those of mated females, and mated females with small plugs to those with large plugs. They were also attracted to female volatile cues. This study suggests that males are able to extract fine‐scale information on mating status from female draglines.     

Mating behavior of male deer ticksIxodes dammini (Acari: Ixodidae)

To analyze the sexual behavior of male black-legged deer ticks Ixodes dammini,we collected ticks infesting 202 white-tailed deer. On average, 17.7 males and 8.8 females infested each deer. Field-collected males copulated with a mean of 2.25 females, and virgin males mated with 2.4 females. On experimental hosts, males established sexual contact with feeding females and repelled other males, and about half remained paired after their mate detached. Engorged females continue to be receptive, and males mate more readily with them than with nonfed females. We conclude that male I. damminiare endowed with a repertoire of behaviors which favor an opportunistic mating before seeking a host and a preference for mating with feeding females on the host accompanied by tenacious mate guarding.     

First experimental evidence for female mate choice in a nocturnal primate

Female mate choice can be hypothesised in most nocturnal primates, since females show a higher investment in their offspring than males. The aim of this experimental study was to investigate if female grey mouse lemurs perform mate choice and whether age, relatedness (to the male), or male advertisement call activity systematically influence their decisions. A two-way mate choice design was developed in which females could choose between two males. Mate choice was deduced from the time spent in proximity to the males and from mating behaviour. During oestrus 12 of 17 females participated actively in the experiment and all of them showed either a significant spatial (n=11) or behavioural (n=1) preference for one male. In four cases copulations were observed. The influence of age on female mate choice was not statistically significant. In the cases with copulations, however, females mostly preferred the older male. This might indicate a preference for older age as an indicator of experience, fitness, and/or status. The influence of relatedness on female mate choice could not be definitely clarified. However, results imply a mechanism of kin recognition on the basis of familiarity. In the majority of choices, females preferred the male with higher trill call activity. Since trill call activity correlates with the relative dominance status of males, these results suggest an importance of the male dominance status for female mate choice in grey mouse lemurs. Altogether our findings indicate that females use a complex of different cues to choose their mates.     

Male age and sexual experience affect male mating behavior in the hawthorn spider mite,Amphitetranychus viennensis

As is reported, in species with first-male sperm precedence, male age and previous sexual experience play crucial roles in male mating behavior. In the hawthorn spider mite, Amphitetranychus viennensis Zacher, previous studies showed that only females that copulated for the first time could achieve fertilization. Based on this, the effects of male age and mating history on male mate choice and male mate competition were investigated. It was confirmed that males could distinguish virgins from fertilized females but they were unable to discriminate between virgins and unfertilized females. Interestingly, the copulation duration of males mated with fertilized females was much shorter than that of males mated with virgins or unfertilized females. Additionally, for male mating choice, males of all ages and more experienced males preferred 5-day-old virgin females, whereas only less experienced males preferred 1-day-old virgin females. In male-male competition, 3-day-old males were more competitive and obtained more copulations compared with others. Copula duration was closely related to male age. Though no significant differences were observed in mating competition between virgin and mated males, copula duration of males in first copulation was the longest and gradually shortened in subsequent copulations. In all, this investigation demonstrated that male age and sexual experience affected male mate choice and male-male competition, leading to further insight into the influences of male age and sexual experience on the reproductive fitness of both sexes.

     

Mating Status Effects on Sexual Response of Males and Females in the Parasitoid Wasp <Emphasis Type="Italic">Urolepis rufipes</Emphasis>

Although mate preferences are most commonly examined in females, they are often found in both sexes. In the parasitoid wasp Urolepis rufipes, both female and male mating status affected certain aspects of sexual interactions. Female mating status mattered only in the later stages of mating. Males did not discriminate between virgin and mated females in terms of which they contacted or mounted first. However, once mounted, most virgin females were receptive to copulation, whereas very few mated females were. Whether a male’s mating status affected his own sexual response depended on the female’s ability to respond and the stage of mating. Examining male behavior toward dead females allowed elimination of the role of female behavior in how males responded. Virgin and mated males are both attracted to dead females as evidenced by their fanning their wings at such females. However, mated males were quicker than virgin males to contact and to mount in an experiment with dead females, whereas there was no such differential response in an experiment with live females. This difference is consistent with greater female sexual responsiveness to virgin males. Male mating status also affected female receptivity to copulate. Once mounted, live virgin females were less likely to become receptive to copulation by mated males than to virgin males, but only in a choice experiment, not in a no-choice experiment.     

Male sexual cannibalism in a sand‐dwelling wolf spider with sex role reversal

Sexual cannibalism usually involves females attacking and consuming males before, during or after copulation. Sex role reversed systems may provide insight into the debate about whether it arises as mistaken identity, a spillover in female aggressiveness, foraging decisions, and/or extreme mate choice. In such systems, males may be selective and voracious to compensate for their higher reproductive costs, and thus males may be the sexually cannibalistic sex. Allocosa brasiliensis shows a reversal in sex roles and male‐biased sexual size dimorphism (the opposite of the common pattern in spiders). The present study aimed to test whether males cannibalize or mate according to female reproductive status or body characteristics. Each of 20 adult males was consecutively exposed to one virgin and one mated female, alternating the order of exposure. Males preferred to mate with virgin females in good body condition and heavier‐mated females. Males attacked 15% of virgins and 40% of mated females and cannibalized 10% and 25% of the total trials, respectively. The astonishing male cannibalistic behaviour best agrees with extreme mate choice hypotheses because attacks were more frequent on mated females of low body condition. This is the first report of male sexual cannibalism in a sex role reversed system. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 68–75.     

Male and Female Mate-Choice Decisions by Evarcha culicivora, An East African Jumping Spider

There has been a considerable recent interest in the criteria by which animals choose mates and in the extent to which mating systems tend to be based on mutual mate choice. In this study, we consider Evarcha culicivora, a salticid spider from East Africa. This species has some unusual characteristics, including active display by females as well as males, males that kill females more frequently than females kill males and wide intrasexual variation in body size. For females, larger males are especially dangerous. Here, we demonstrate, using two experimental designs (live‐mate choice and mount choice), that virgin males, virgin females and previously mated males prefer larger opposite‐sex individuals as potential mates, but mated females prefer smaller, safer males as potential mates.     

Chemosensory cues allow male Tenebrio molitor beetles to assess the reproductive status of potential mates

Males of many insect species, including beetles, choose their mates according to their reproductive status. However, the ways in which male beetles evaluate female reproductive status have received little attention. We tested the existence of male mate choice in the mealworm beetle, Tenebrio molitor, by observing mating and courtship behaviour of males given simultaneous access to pairs of females differing in their reproductive status: (1) mature versus immature; (2) virgin versus previously mated; (3) familiar (mated with the experimental male) versus unfamiliar (mated with a different male). Males courted and mated preferentially with mature and virgin females. To determine whether chemical cues played a role in these discriminations, we exposed males to filter paper squares bearing chemical cues from different types of females: (1) virgin versus mated; (2) mature versus immature. Males were significantly more attracted to those squares bearing chemical cues from virgin and mature females, suggesting that males can assess female reproductive status on the basis of chemical cues alone.     

Mate Choice by Non-Virgin Females Contributes to Reproductive Isolation between Populations of the Harlequin Beetle-Riding Pseudoscorpion

Determining whether reproductive isolation evolves through mate choice and/or gametic factors that prevent fertilization or through the post‐zygotic mechanisms of hybrid sterility or inviability is fundamental to understanding speciation. Investigation of the pre‐ and post‐zygotic components of reproductive isolation is facilitated in the pseudoscorpion, Cordylochernes scorpioides, by its indirect method of sperm transfer and viviparous embryonic development. Previous research on this species, in which mate discrimination was assessed in virgin females, suggested that female choice played only a minor role in reproductive isolation between populations from French Guiana and Panamá. Here, in a study of three allopatric populations of C. scorpioides from Panamá, we assessed mating‐stage isolation in both virgin and once‐mated females, and found that female discrimination depends critically on mating status. Virgin females were almost invariably receptive, showing no tendency to discriminate against males from allopatric populations. By contrast, non‐virgin females were significantly more likely to reject foreign males than males from their own population. Male sexual motivation could not account for differences in either female sexual receptivity or male success in sperm transfer. Allopatric and sympatric males did not differ in number of spermatophores deposited as either a female’s first or second mate. Nonetheless, allopatric males achieved significantly lower sperm transfer success not only with choosy, non‐virgin females but also with virgin females. Given the lack of behavioral discrimination by virgin females, female receptivity was not the only factor influencing differences in sperm transfer success. Multivariate analysis of spermatophore morphology suggests that the higher failure rate of matings between allopatric males and virgin females resulted from population differences in sperm packet architecture. Overall, our findings indicate that assessment of discrimination against allopatric males that is limited to virgin females may seriously underestimate the contribution of female mate choice to reproductive isolation between populations.     

Sexual History Affects Mating Behavior and Mate Choice in the Crayfish Orconectes limosus

Because mating entails both costs and potential benefits to both sexes, males and females should be under selection to make optimal choices from among available potential mates. For example, in some cases, individuals may benefit by using information on potential mates' previous sexual histories to make mate choices. In such cases, the form and direction of these benefits may vary both between the sexes and based on the sexual history of the choosing individuals themselves. We investigated the effects of recent previous sexual history on the mate choice and mating behavior of both males and females of the crayfish Orconectes limosus. In one experiment, we found that opposite‐sex dyads comprising crayfish that had both mated 7–8 d previously with other conspecifics were significantly less likely to mate than dyads in which at least one crayfish was unmated. In a second experiment, we found that, when presented with a choice of tethered (but free to move) opposite‐sex conspecifics, only virgin females discriminated between males based on sexual history, showing a preference for virgin males over recently mated males. Mated females, mated males, and virgin males showed no preferences based on the sexual histories of potential mates. We discuss the implications of these inferences in the context of what was previously known about mating behavior and potential sperm limitation in crustaceans and other taxa.     

Male Mate Choice in the Guppy (Poecilia reticulata): Do Males Prefer Larger Females as Mates?

Although females are the choosier sex in most species, male mate choice is expected to occur under certain conditions. Theoretically, males should prefer larger females as mates in species where female fecundity increases with body size. However, any fecundity‐related benefits accruing to a male that has mated with a large female may be offset by an associated fitness cost of shared paternity if large females are more likely to be multiply mated than smaller females in nature. We tested the above hypothesis and assumption using the Trinidadian guppy (Poecilia reticulata) by behaviourally testing for male mate choice in the laboratory and by ascertaining (with the use of microsatellite DNA genotyping) patterns of male paternity in wild‐caught females. We observed significant positive relationships between female body length and fecundity (brood size) and between body length and level of multiple paternity in the broods of females collected in the Quaré River, Trinidad. In laboratory tests, a preference for the larger of two simultaneously‐presented virgin females was clearly expressed only when males were exposed to the full range of natural stimuli from the females, but not when they were limited to visual stimuli alone. However, as suggested by our multiple paternity data, males that choose to mate with large females may incur a larger potential cost of sperm competition and shared paternity compared with males that mate with smaller females on average. Our results thus suggest that male guppies originating from the Quaré River possess mating preferences for relatively large females, but that such preferences are expressed only when males can accurately assess the mating status of encountered females that differ in body size.     

Effects of morphological traits,age and copulation experience on mate choice in Ophraella communa

Ophraella communa is a biological control agent of invasive common ragweed, Ambrosia artemisiifolia. To understand the mate choice tactic of the beetle and improve mass-rearing of high-quality populations, the effects of morphological traits, age and copulation experience on mate choice in this beetle were studied in the laboratory. The results showed thatmate choice of male or female was related to certain adult morphological traits. Wing length, black streak width of frons and metaleg femur length of males were central to female mate choice. Females with longer wing length, black streak width of frons, pronotum width and foreleg tibia length were more attractive to males than those with the smaller ones. The chosen rate of older males was significantly higher than those of younger ones, and the chosen rate of females reached a maximum value on the 8th day after eclosion. The newly copulated females were less attractive to males than virgins, but females that have copulated in the distant past were more attractive than or were similar to virgins. The chosen rates of virgin males were significantly higher than those of newly copulated and 8 days past copulated ones, but no difference between virgin males and 3, 5 or 12 days past copulated ones in O. communa. The results of our study have added much needed empirical data regarding the significance of morphological traits, age and copulation experience as a source of variation in insect copulation signals. In addition, the results provide valuable information for mass-rearing of high-quality populations of O. communa.     

Decision-making conditions for intra- or inter-nest mating of winged males in the male-dimorphic ant <Emphasis Type="Italic">Cardiocondyla minutior</Emphasis>

Only winged male and female ants generally mate through nuptial flight during the reproductive season. In the ants of Cardiocondyla, the males show wing dimorphism and their reproductive strategies differ depending on the differences in wing morphology. It has been suggested that wingless “ergatoid” males bearing very similar external morphologies to workers mate within natal nests, whereas winged males bearing typical ant male morphology disperse from their nests to mate. However, some behavioral observations suggest that the winged males of some Cardiocondyla ants such as C. obscurior and C. minutior may mate within natal nests before dispersion. We evaluated the factors affecting the mating behaviors of the winged males of C. minutior under laboratory conditions. We found that (1) the winged males remained and mated with virgin females in natal nests when either virgin winged females or the relatively mature pupae of winged females (i.e., at least 10 days) were present in the nest, (2) the winged males dispersed to adjacent nests with virgin winged females when only mated queens and the relatively young pupae of winged females (i.e., <9 days) were present in the nest, and (3) all winged males were accepted by the workers of non-natal nests irrespective of the distance from the natal nests in the field. Although most ergatoid males were accepted by the workers of close non-natal nests, they were all attacked and killed by the workers of distant non-natal nests. These results suggest that intra-nest mating and the dispersion of the winged males of C. minutior are facultatively determined by the condition of winged females (virginity and relative pupal age) in natal nests. Furthermore, our results suggest that winged males are likely to seek mating partners chemically and to mate with virgin winged females.     

Opportunities for female choice in the bed bug Cimex lectularius

Bed bugs are cited as exemplars of sexual conflict because mating can only occur via traumatic insemination. However, past antagonistic coevolution between the sexes does not necessarily preclude current female choice. Here, we investigate opportunities for precopulatory female choice in bed bugs. We examined whether females seek out mating opportunities when they gain the most benefit: when females are virgin and/or have recently fed. But, we found that female mating and feeding status had little effect on female attraction to males and male odor. To determine whether females approach male harborages (home crevices) to seek matings in nature, we investigated where matings occurred among unfamiliar pairs of bed bugs. We found that, despite female attraction to male odor, matings were most likely to take place in the female's harborage rather than the male's harborage. We also examined the effect of feeding on male and female ability to mate. Whereas previous research reported that engorgement impaired female ability to refuse matings, we found that male feeding status had a larger effect on the success of mating encounters than female feeding status. Fed males had poor mating success, suggesting that males may be faced with a trade‐off between mating and feeding.     

Female mate choice and mating costs in the polyandrous butterflyPieris napi (Lepidoptera: Pieridae)

Males of the green-veined white butterfly (Pieris napi L.) transfer large ejaculates that represent on average 15% of their body mass when mating for a first time. Shortly after mating a male is able to transfer only a small ejaculate when mating a second time. Male ejaculate production plays a crucial role in the mating system ofP. napi because females use male-derived nutrients for egg production and somatic maintenance. Here we study how timing of female rematings and copulation duration are influenced by the mating history of their mates and, also, study if females exert mate choice to minimize their mating costs. Mating with a recently mated male increased female mating costs by increasing time in copula and mating frequency. Virgin females that mated with virgin males remated after an average of 6 days, whereas virgin females that mated with recently mated males remated after an average of 2 days. Moreover, copulations involving recently mated males lasted on average almost 7 h, whereas copulations involving virgin males lasted on average 2 h. Recently mated males were eager to remate, in spite of the fact that the size of the ejaculate they transfer is small and that they remain in copula for a long time. Hence it seems that males are more successful in the sexual conflict over mating decisions and that females do not minimize mating costs by choosing to mate preferentially with virgin males.     

Kin discrimination and female mate choice in the naked mole-rat Heterocephalus glaber

Naked mole-rats are fossorial, eusocial rodents that naturally exhibit high levels of inbreeding. Persistent inbreeding in animals often results in a substantial decline in fitness and, thus, dispersal and avoidance of kin as mates are two common inbreeding avoidance mechanisms. In the naked mole-rat evidence for the former has recently been found. Here we address the latter mechanism by investigating kin recognition and female mate choice using a series of choice tests in which the odour, social and mate preferences of females were determined. Discrimination by females appears to be dependent on their reproductive status. Reproductively active females prefer to associate with unfamiliar males, whereas reproductively inactive females do not discriminate. Females do not discriminate between kin and non-kin suggesting that the criterion for recognition is familiarity, not detection of genetic similarity per se. In the wild, naked mole-rats occupy discrete burrow systems and dispersal and mixing with non-kin is thought to be comparatively rare. Thus, recognition by familiarity may function as a highly efficient kin recognition mechanism in the naked mole-rat. A preference by reproductively active females for unfamiliar males is interpreted as inbreeding avoidance. These findings suggest that, despite an evolutionary history of close inbreeding, naked mole-rats may not be exempt from the effects of inbreeding depression and will attempt to outbreed should the opportunity arise.