Mating status regulates post‐mating refractory period in Striacosta albicosta females

In polyandrous insect species, males may transfer substances to reduce sperm competition by affecting female sexual receptivity. In this study, we determined the incidence of polyandry in females of Western bean cutworm (WBC), Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), and investigated the influence of both previous female and male mating history on the duration of mating, the female refractory period, and subsequent calling behavior of females under controlled laboratory conditions. The mating status of WBC males influenced mating duration, with copulations involving previously mated males taking longer, possibly related to the time required to produce an ejaculate. The duration of the female refractory period and the onset time of recalling during the scotophase were both affected by female mating history, but not by that of the males. Females had a shorter refractory period and resumed calling activity earlier after their second and third matings than after their first mating. The earlier onset of calling by previously mated females could reduce competition with virgin females and their shorter refractory period could explain the high incidence of polyandry observed in nature.     

Microsatellite analysis of female mating behaviour in lek-breeding sage grouse

We used microsatellite DNA markers to genotype chicks in 10 broods of lek-breeding sage grouse, Centrocercus urophasianus, whose mothers' behaviour was studied by radio-tracking and observing leks. Previous behavioural studies suggested that almost all matings are performed by territorial males on leks and that multiple mating is rare. Two broods (20%) were sired by more than one male. Genetic analyses of the broods of eight females that visited an intensively studied lek were consistent with behavioural observations. Four females observed mating produced singly sired broods and males other than the individual observed copulating were excluded as sires for most or all of their chicks. Territorial males at the study lek were excluded as sires of broods of four other females that visited the lek but were not observed mating there. Radio-tracking suggested that two of these females mated at other leks. Our results confirm the reliability of mating observations at leks, but do not rule out a possible unseen component of the mating system.     

Reproductive behaviour of the South American fruit fly Anastrepha fraterculus (Diptera: Tephritidae): laboratory and field studies

Abstract. The mate choice, courtship and oviposition behaviour of laboratory-reared and field-collected Anastrepha fraterculus (Wied.) were compared. In laboratory cultures in Southampton the duration of male calling activity in small leks increased gradually from 1-2h at 5 days old to up to 7 h at 10 days. This finding correlates with previous reports on the time at which male salivary glands, which are believed to produce sex pheromone, are fully developed. Wild flies which emerged from infested fruits in Brazil began to oviposit on the day they mated, whereas in laboratory flies oviposition began 1 day following the first mating. Both types of fly usually defended their position on a particular fruit throughout the day, and re-mated with either virgin or mated males. There was no significant difference in mating duration. Females did not copulate before the mean age (±SE) of 16.8±0.9 days. For both types of flies mating initiation occurred in the first 2h of photophase, with virgin females choosing mainly mated males. The average number of matings in the laboratory was three for females and four for males, and the interval between matings in females was significantly increased after the second mating. It is suggested that the tendency of virgin females to mate with mated males will lead to increased fitness, as males are on average 48 days old at their second mating. The potential life span of around 200 days for both sexes would allow adults to bridge the gap between seasonally available fruits in warm-temperate and sub-tropical South America.     

Laboratory breeding studies of freshwater crayfish, Austropotamobius pallipes (Lereboullet)

SUMMARY. 1. Mature crayfish, collected from an Irish lake before breeding had started, were held in breeding combinations and their mating and brooding activities observed.
2. All mating attempts were initiated by the male. A single mating led to spawning within 6 days but a subsequent mating cancelled the effects of the first. Males mated more often when there were more females present. Males lacking a major cheliped mated less often than did normal males.
3. Larger males mated more often than did smaller males, and although males showed no female size preference, matings were less frequent and generally unsuccessful when males were much larger than females; the female was usually killed. Large females mated successfully with smaller males.
4. Females held at high densities with a larger male mated earlier than at low densities. However, aggression also increased with density; at high densities males fought and killed females.
5. Males held in pairs without females fought; in occasional mating attempts spermatophores were not positioned correctly. Paired females rarely fought; all spawned normally although unmated. Although their eggs soon died and were removed during grooming, brooding behaviour continued for at least 2 months.
6. Brooding females held in pairs shed pleopodal eggs during aggressive encounters. Females held singly showed a lower initial rate of egg loss.     

Reduction in the attraction of males to females after mating in the rice leaf bug Trigonotylus caelestialium

The influence of mating on the extent to which males are attracted to females in Trigonotylus caelestialium (Heteroptera: Miridae) was examined. No differences in attraction of males to mated and virgin females were observed within 3–5 h of mating, but males became less attracted to females 1 to 2 days after the first mating. The difference in male attraction to mated vs virgin females disappeared at 4 days after mating. These results indicate that reduced attraction of males to mated females occurs after a certain time interval, and persists for a few days. Furthermore, males were less attracted to females that had mated with virgin vs recently mated males, i.e. males that had just mated with another female at 1 and 2 days after mating. The ejaculate expenditure of recently mated males was less than that of virgin males. Hence, the amount of male ejaculate transferred to females during mating, rather than the act of mating, might influence the attraction of males to females. The results demonstrate that mating reduces the attraction of males to females in T. caelestialium on the basis of direct observation of male behavior.     

Male crickets adjust the viability of their sperm in response to female mating status

Sperm competition theory predicts that males should allocate sperm according to the number of competing ejaculates. Prudent allocation of sperm in response to different levels of sperm competition has been found across a number of taxa; however, some studies suggest that males may not always allocate sperm as expected. Here we examine sperm allocation in the Australian field cricket Teleogryllus oceanicus, using female mating status (virgin, singly mated, or multiply mated) to manipulate male perception of sperm competition risk and intensity. Consistent with theory, we found that male crickets adjust their ejaculates in response to female mating status. However, rather than altering the absolute numbers of sperm transferred to a female, males altered the quality of their sperm. Males ejaculated sperm of low viability (proportion of live vs. dead sperm) when mating with virgins, increased sperm viability when mating with singly mated females, but reduced sperm viability when mating with multiply mated females. Our results show that variation in ejaculate quality can be an important aspect of strategic ejaculation by males and suggest caution in the interpretation of studies in which males do not appear to allocate sperm according to theory.     

The effect of interspecific mating on sex ratios in the twospotted spider mite and the Banks grass mite (Acarina: Tetranychidae)

Mixed populations of the twospotted spider mite (TSM),Tetranychus urticae (Koch), and the Banks grass mite (BGM),Oligonychus pratensis (Banks), occur on corn and sorghum plants in late summer in the Great Plains. Interspecific matings between these arrhenotokous species occur readily in the laboratory but yield no female offspring. The effect of interspecific mating on female: male sex ratios was measured by examining the F₁ progeny of females that mated with both heterospecific and conspecific males in no-choice situations. TSM females that mated first with BGM males and then with TSM males produced a smaller percentage of female offspring than TSM females that mated only with TSM males (43.1±5.8 and 78.9±2.8% females, respectively). Similarly, BGM females mated with heterospecific males and then with conspecific males produced fewer female offspring than females mated only with BGM males (55.7±5.2 and 77.5±2.5%, respectively). Lower female: male sex ratios were produced also by BGM females that mated with TSM males after first mating with conspecifics (62.4±3.4%). In mixed populations containing males of both species, females also produced lower female: male sex ratios, but these ratios were not as low as expected based on mating propensities and progeny sex ratios observed in no-choice tests. These data suggest that interspecific mating may substantially reduce female fitness in both mite species by reducing the output of female offspring, but in mixed populations this effect is mitigated by unidentified behavioral mechanisms.     

Sexual behavior of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae)

To get a better understanding of the mating behavior of the navel orangeworm, Amyelois transitella (Walker), we developed a robust laboratory colony derived from larvae collected in Bakersfield, California and fed on dried, roasted pistachio. In the lab at 25 degrees C, most of the mating activity was observed during the last hour of the scotophase and for the first 30 min of the photophase. Female calling was characterized by the abdomen being protruded between the wings with the distal segments perpendicular to the body and exposing a pheromone gland, as well as by continuous antennation. Males approached calling females from a short distance by displaying wing fanning and antennation. When a male antennated on a calling female's abdomen, she either accepted the male and lowered the abdomen, or walked away. The accepted male made a final approach parallel to the female's body, but after coupling he rotated 180 masculine with male and female remaining in a linear, abdomen-to-abdomen position for over 3 h in average. In a possible strategy to maximize the chances of mating, the sex ratio was significantly skewed towards males in the first two days of emergence. Almost 80% of mating took place in the first two days after adult emergence, with females mating only once. About 55% of males mated only once and approximately 40% of the observed males mated twice and 5% tree times.     

Large Numbers of Matings Give Female Field Crickets a Direct Benefit but not a Genetic Benefit

Female crickets can potentially gain both direct and indirect benefits from mating multiple times with different males. Most studies have only examined the effects of small numbers of matings, although female crickets are capable of mating many times. The goal of this paper is to examine the direct and indirect benefits of mating large numbers of times for female reproductive success. In a previous experiment, female Gryllus vocalis were found to gain diminishing direct benefits from mating large numbers of times. In this study I attempt to determine whether mating large numbers of times yields similar diminishing returns on female indirect benefits. Virgin female Gryllus vocalis crickets were assigned to mate five, ten or 15 times with either the same or different males. Females that mated more times gained direct benefits in terms of laying more eggs and more fertilized eggs. Females that mated with different males rather than mating repeatedly with the same male did not have higher offspring hatching success, a result that is contrary to other published results comparing female reproductive success with repeated versus different partners. These results suggest that females that mate large numbers of times fail to gain additional genetic benefits from doing so.     

Why is Female Choice not Unanimous? Insights from Costly Mate Sampling in Marine Iguanas

Females do not unanimously choose the single 'best' male, even when female choice is strong, such as in leks, or in polygynous mating situations. A possible explanation is that females base their choices on limited information, perhaps because gathering information is costly. We tested this hypothesis by continuously observing individual female marine iguanas throughout the mating period in order to document the information they gathered about each potential mate. Females actively visited approximately five additional males during the 3 d prior to copulation, compared to the males seen on their normal foraging routes. Females were more likely to visit large-bodied males, but preferentially copulated with the male that had the highest display rate of all males they visited. Females that mated on a dense territory cluster mated with more active males than did those that mated on dispersed territories. However, females on a dense cluster also lost more body mass, potentially as a consequence of high rates of interaction with males. This mass loss may represent an important cost and result from postural changes in response to male attention. Such costs may explain why females only gather a certain amount of information and why females on dispersed territories choose less active mates. Lack of complete information introduces subjectivity into female choice: what is perceived as best by one female may not be perceived as best by another. Thus, lack of complete information may prevent unanimity of female choice.     

Male age affects female mating preference but not fitness in the monandrous moth Dendrolimus punctatus Walker (Lepidoptera: Lasiocampidae)

It is widely accepted that male age can influence female mating preference and subsequent fitness consequences in many polyandrous species, yet this is seldom investigated in monandrous species. In the present study, we use the monandrous pine moth Dendrolimus punctatus to examine the effects of male age on female mating preference and future reproductive potential. In multiple male trials, when permitted free mating from an aggregation consisting of virgin males aged 0 (young), 2 (middle-aged) and 4 (old) days, virgin females preferentially mate with young and middle-aged males, although mating latency and mating duration are independent of male age. In single male trials, when virgin females are randomly assigned single virgin males of known age, a negative correlation is found between mating success and male age in this species. However, we find that male age also has no effect on mating latency and mating duration. Further fitness analysis reveals that females do not receive benefits in terms of oviposition period, total egg production, average daily egg production, percentage of egg hatching, longevity, expected reproduction and relative expected reproduction from mating with young and middle-aged males compared with mating with old males. The results of the present study are the first demonstrate that females mated preferentially with younger males but gain no apparent fitness benefits in a monandrous moth species.     

Calling is an honest indicator of paternal genetic quality in poison frogs

Several competing hypotheses have been put forward to explain why females of many species mate preferentially with males possessing the most conspicuous signals (e.g., ornaments, displays, or songs). We performed a laboratory experiment using two species of poison frogs, Dendrobates leucomelas and Epipedobates tricolor, to test the hypothesis that male calling performance is an honest indicator of parental quality. Our analyses are based on data from behavioral observations of mating activities of captive-reared individuals (and their offspring) that were housed in terraria for four consecutive breeding seasons. Male mating success increased with male calling rate and chirp duration in both species, suggesting that females preferred males with more elaborate calls. Because calling performance improved with age in D. leucomelas, female poison frogs that prefer males with more elaborate calls in the wild may end up mating with older males that have already proven their ability to survive. Females that mated with good callers obtained higher quality offspring. Eggs fertilized by males with high calling rates and long chirp durations had higher hatching success and produced tadpoles that were more likely to metamorphose into surviving frogs. As a consequence, females that mated with males with high calling performance obtained more surviving offspring per egg, compared to females that mated with poor callers. Collectively, our findings comply with the notion that female poison frogs prefer to mate with good callers because calling performance is a reliable predictor of offspring quality. The possible influence of maternal allocation and reasons for the strong effect size compared to previous studies are discussed.     

Factors affecting female sexual receptivity in the planthopper, Prokelisia dolus

Abstract. The mating system of Prokelisia dolus Wilson (Homoptera: Delphacidae) was characterized by determining: if males and females multiply mate; when transitions occur in female sexual receptivity, what triggers sexual refractoriness; and what behaviours characterize unreceptive virgins, receptive virgins, and unreceptive mated females. Males copulated with up to six females in less than 1 h, but completely inseminate, on average, only the first four females. Females rarely mated more than once, unless males were depleted of sperm due to previous copulations or if copulation was interrupted (if duration was<2 min). Male and female calling was associated (100% and 91%, respectively) with sexual receptivity and resultant matings. The transition from unreceptive virgin to receptive (calling) mature virgin occurred 48 h posteclosion, and all were mated by day 4. Females that were sexually immature and those completely inseminated did not call. Rejection of males by females included walking away from approaching males (65%), female kicking (7%), and abdominal lifting (5%). Rejection of males was observed by immature, mature and calling, and mated females. Sexual refractoriness was not triggered by acoustic and visual stimuli or mechanical stimulation of genitalia. Refractoriness was also not triggered by reception of small quantities of sperm because some females laid a few viable eggs yet calling was not terminated. Sexual refractoriness was activated by a substance in the ejaculate as demonstrated by injection into the haemocoel of male accessory glands or testes and homogenates of seminal vesicles. This is the first study that documents the role of male ejaculate in inhibiting female sexual receptivity in Hemiptera (Homoptera).     

Long-term effects of accelerated or delayed sexual maturation on reproductive output in wild female house mice (Mus musculus)

The effects of acceleration and delay of puberty in female house mice on survival and reproduction were tested using 6 experimental groups: (1) control females mated at the time of first oestrus, (2) females mated at weaning, (3) females treated with male urine starting at weaning and mated at first oestrus, (4) females housed in groups and mated at first oestrus, (5) females housed alone, treated with urine from grouped females and mated at first oestrus, and (6) females housed alone and mated at 68 days of age. Females caged with males at weaning or treated with male urine and mated at puberty had lower rates of survival to 180 days of age, but did not differ in rates of fertility from mice in the other four treatments. Those females that were housed with males from weaning or treated with male urine also had smaller total numbers of litters, fewer total young, and smaller average litter sizes than did females for which the age of mating was delayed, by grouping or treatment with urine from grouped females, or by being held until age 68 days before mating. Control females mated at first oestrus generally were intermediate or did not differ from the male treatments on these dependent variables. There were no differences in the average number of female young/litter across the 6 treatments. However, females that were delayed in age of first mating had significantly more male young/litter than did females that were accelerated in their sexual development or control females.(ABSTRACT TRUNCATED AT 250 WORDS)     

Female mate choice across spatial scales: influence of lek and male attributes on mating success of blue-crowned manakins

Lekking males compete for females within and among leks, yet female choice is expected to work differently at each of these spatial scales. We used paternity analyses to examine how lek versus male attributes influence mate choice in the blue-crowned manakin Lepidothrix coronata. We tested the hypotheses that females prefer (i) to mate at larger leks where a larger number of potential mates can be assessed, (ii) to mate with unrelated or highly heterozygous males expected to produce high-quality offspring, (iii) to mate with males that display at higher rates, and that (iv) display honestly reflects male genetic quality. Our results show that (i) males at larger leks are not more likely to sire young, although females nesting close to small leks travel further to reach larger leks, (ii) siring males are not less related to females or more heterozygous than expected, (iii) within a lek, high-display males are more likely to sire young, and (iv) both male heterozygosity and display rate increased with lek size, and as a result display does not reliably reflect male genetic quality across leks. We suggest that female mate choice in this species is probably driven by a Fisherian process rather than adaptive genetic benefits.     

Multiple mating of male and female codling moth (Lepidoptera: Tortricidae) in apple orchards treated with sex pheromone

Studies were conducted with codling moth, Cydia pomonella L., to evaluate the mating status of male and female moths in apple, Malus domestica (Borkhausen), orchards treated with and without sex pheromone dispensers. Laboratory studies first examined the effect of multiple mating of male and female moths on female fecundity and egg fertility. Females that had mated three times had a significantly higher fecundity than singly mated moths. Sequential mating by male moths had no effect on the fecundity of female moths or egg fertility. However, male moth age did impact female fecundity, with significantly fewer eggs laid after mating with virgin 1- versus 3-d-old males. The mean size of the first spermatophore transferred by males was significantly larger than all subsequent spermatophores. Classifying spermatophores based on size was used in field sampling to categorize the mating status of the female's partner. The proportion of mated females with small spermatophores (partner had previously mated) was significantly higher in treated versus untreated orchards. The proportion of female moths caught in traps baited with pear ester that were virgin was low (相似文献   

Polyandry in grain beetles, Tenebrio molitor, leads to greater reproductive success: material or genetic benefits?

Females that mate with more than one male may derive both materialand genetic benefits, and differentiating between the two benefitsis often difficult. We tested for both material and geneticeffects associated with multiple mating in the highly promiscuousyellow mealworm beetle, Tenebrio molitor. Females that matedfour times to the same male laid more eggs and produced morelarvae than females that mated only once. Whether copulationsoccurred on the same day or over several days, the result wasan immediate increase in the production of eggs by females.Some females were kept on a restricted diet to test whethernutrients in the spermatophore disproportionately benefittedfood-deprived females. Although females on poor diets producedfewer and smaller offspring, diet did not significantly affect the proportional benefit of mating treatment on female fecundity.By controlling for male mating history, we were able to separatethe effects of mating with different males from the effectsof receiving multiple spermatophores from the same male. Femalesthat mated with four different males achieved substantial gainsin numbers of eggs produced (32% increase) beyond those offemales that mated an identical number of times with the same male. We found no evidence that males allocate fewer sperm toprevious mates. Egg hatchability was unaffected by mating behavior,suggesting that genetic incompatibility at that stage is notresponsible for the low reproductive success of females matedwith a single male. These results suggest that females maydelay or reduce oviposition or may be incapable of achieving maximal fecundity until they have gained the material and/orgenetic benefits of mating with multiple males.     

Diet, sex, and death in field crickets

Senescence is shaped by age-dependent trade-offs between fitness components. Because males and females invest different resources in reproduction, the trade-offs behind age-dependent reproductive effort should be resolved differently in the sexes. In this study, we assess the effects of diet (high carbohydrate and low protein vs. equal carbohydrate and protein) and mating (once mated vs. virgin) on lifespan and age-dependent mortality in male and female field crickets (Teleogryllus commodus), and on male calling effort. Females always had higher actuarial ageing rates than males, and we found a clear lifespan cost of mating in females. Mated males, however, lived longer than virgin males, possibly because virgins call more than mated males. The fastest age-dependent increases in mortality were among mated males on the high-carbohydrate diet. Males on a high-carbohydrate diet showed a faster increase in calling effort earlier in life, and a more pronounced pattern of senescence once they reached this peak than did males on a diet with equal amounts of protein and carbohydrates. Our results provide evidence that the cost of mating in this cricket species is both diet and sex-dependent, and that the underlying causes of sex differences in life-history traits such as lifespan and senescence can be complex.     

Male courtship success and female discrimination in the mediterranean fruit fly (Diptera: Tephritidae)

The mating success of individually marked male Mediterranean fruit flies was monitored over 6 consecutive days in the laboratory. Mating frequency was nonrandom, as the numbers of both males that failed to mate and males that mated many (more than four) times were much higher than expected by chance alone. Differential mating success resulted in part from intermale variation in activity level. Male copulatory success was positively correlated with the numbers of courtships performed, attempted copulations (mountings), and females courted. Male-male aggression, on the other hand, and a negligible effect on male mating success. Female choice also appeared to influence male mating frequency. Fewer than 10% of courtships resulted in mating, and in most cases females terminated courtship by simply moving away from the male. Females that did mate generally selected males having higher copulatory scores than previously rejected males.     

Influence of age at mating on the reproductive performance of Parthenium beetle,Zygogramma bicolorata (Coleoptera: Chrysomelidae)

Abstract Age-specific mating incidence, sexual maturation and effect of age at mating on reproductive performance of the Parthenium beetle, Zygogramma bicolorata Pallister, was studied. Based on 50% mating incidence the calculated age of sexual maturation of males and females was 10.5 and 11.1 days, respectively, which was not statistically significant. However, on the basis of age at first mating, that is, sexual maturity, females matured 2 days earlier than males. Fecundity, pre-oviposition, oviposition and post-oviposition period and female longevity appear to be influenced by female age at mating with reproductive performance peaking at 30 days. On the other hand, egg viability was influenced by male age and was highest when males mated at the age of 40 days. To summarise, egg production and timing of egg deposition was female age-dependent, whereas egg fertility was male age-dependent. It was also observed that females mated at a later age and laid a higher number of eggs immediately after mating than did earlier mated females. This was ostensibly in a bid to increase fitness by maximizing reproductive output in the reduced life span available. This is the first investigation on the effect of age of females at mating on reproduction in this beetle.