Effect of multiple mating on the reproductive performance of the rice leaffolder moth,Cnaphalocrocis medinalis (Lepidoptera: Crambidae)

To clarify whether multiple mating of females and males affects the reproductive performance of the rice leaffolder moth, Cnaphalocrocis medinalis (Guenée), we examined the effect of the number of matings (once, twice, or three times) for females (female treatment) and males (male treatment) on the incidence of moth mating, number of eggs laid, egg hatchability, and adult longevity. We also compared the effect of multiple mating imposed on males or females separately with the effect of that imposed on both sexes simultaneously (both sexes treatment). The incidence of mating of females and males that mated three times (3-mated females and males) was significantly lower than for females and males that mated twice or once (2-mated or 1-mated females and males). The incidence of mating of 1-mated moths (both sexes) was significantly higher than for 2-mated or 3-mated moths (both sexes). Two-mated or 3-mated females laid significantly more eggs with significantly higher hatchability than 1-mated females. Females that mated with 1-mated males (second male mating) or 2-mated males (third male mating) laid significantly fewer eggs than those that mated with virgin males (first male mating). Females laid significantly more eggs after the second and third matings for moths of both sexes than after the first mating for moths of both sexes. The mechanisms of improvement and decline of female reproductive performance when multiple mating was imposed on males or females are also discussed in relation to the reproductive biology of C. medinalis.     

Male age, mating status and nuptial gift quality in a bushcricket

Female mate choice occurs in many animals, and in some species females prefer older males. Because older males have demonstrated their survival ability, they may be of higher genetic quality, providing genetic benefits to the offspring of their mates. However, in species where females receive direct benefits of matings, younger males may be more likely to provide more fertile or more nutritious ejaculates, so females may discriminate against older males. Males of the bushcricket Ephippiger ephippiger (Orthoptera: Tettigoniidae) produce large spermatophores at mating (>30% of body weight, circa 10% protein content). Female E. ephippiger discriminate against the song of older males. We examined the effects of male age and mating history on male reproductive investment (spermatophore size, sperm number, nitrogen content). Males produced spermatophores with significantly fewer sperm and of lower nitrogen content on their fourth mating, despite free access to food and a 1-week interval between matings, indicating that there is a cost of mating to males. There was no indication that older virgin males produced lower-quality spermatophores. Rather, older males produced bigger spermatophores of higher nutritional value and containing more sperm. Male age and mating history seem likely to be strongly correlated in the field. We conclude that female E. ephippiger probably prefer the songs of younger males, because in the field, this preference correlates with male mating history and therefore resources provided at mating. Thus, female preference for younger males could reflect discrimination against low-quality nuptial gifts.     

Delayed mating and reproduction in the autumn gum moth Mnesampela privata

• 1 The success of mating disruption using synthetic sex pheromones depends not only on preventing mating, but also on delaying mating in the target insect. Using the geometrid pest of Eucalyptus plantations, Mnesampela privata (Guenée), we determined the effect of delaying mating when imposed on males only, females only or on both sexes simultaneously, for 1, 3, 5 and 7 days.
• 2 Delayed mating had a significant negative impact on reproduction, with a 0.89‐fold decrease in the likelihood of mating and a 0.67‐fold decrease in the likelihood of that mating resulting in fertile eggs for every day that mating is delayed. A mating delay of 7 days reduced the mean number of viable eggs laid to 4–13% of that laid by moths paired immediately after emergence.
• 3 Male only imposed mating delays had a significantly lower effect on reducing the likelihood of pairs mating than when both sexes were delayed. A delay imposed on one sex only or on both sexes simultaneously, however, had a similar negative impact on the proportion of fertile matings as well as on the total number of fertile eggs laid.
• 4 Longevity of mated female and male M. privata was significantly different between mating delay treatments, with a significant decline in female longevity when they mated with older males.
• 5 The underlying mechanisms causing a decline in female reproductive output when a mating delay was imposed on males versus females are discussed in relation to the reproductive biology of M. privata and the potential of using mating disruption strategies to control populations in Eucalyptus plantations.

     

Male size,mating potential and lifetime reproductive success in the field cricket,Gryllus bimaculatus (De Geer)

Male size is known to influence short-term, competitive mating success in the field cricket, Gryllus bimaculatus. Short-term measures of mating success are, however, potentially misleading when considering the influence of sexual selection on male morphology and behaviour. The lifetime mating success of males was investigated in the absence of competition to determine the effects of male size per se on reproductive potential and any effects of female behaviour on male lifetime mating success. The cost of spermatophore production was relatively greater for small males who consequently had a longer refractory period between matings, thus limiting their reproductive potential. Large males had a mating advantage resulting from a differential response of females to the courtship attempts of large and small males. Furthermore, small males were ‘sexually incompetent’ in terms of their ability to attach spermatophores once mounted. There was, therefore, an overall positive relationship between male size and lifetime reproductive success.     

Effects of multiple matings on reproductive fitness of male and female Diaeretiella rapae

Mating frequency and the amount of sperm transferred during mating have important consequences on progeny sex ratio and fitness of haplodiploid insects. Production of female offspring may be limited by the availability of sperm for fertilizing eggs. This study examined multiple mating and its effect on fitness of the cabbage aphid parasitoid Diaeretiella rapae McIntosh (Hymenoptera: Aphidiidae). Female D. rapae mated once, whereas males mated with on average more than three females in a single day. The minimum time lag between two consecutive matings by a male was 3 min, and the maximum number of matings a male achieved in a day was eight. Sperm depletion occurred as a consequence of multiple mating in D. rapae. The number of daughters produced by females that mated with multiple‐mated males was negatively correlated with the number of matings achieved by these males. Similarly, the proportion of female progeny decreased in females that mated with males that had already mated three times. Although the proportion of female progeny resulting from multiple mating decreased, the decrease was quicker when the mating occurred on the same day than when the matings occurred once per day over several days. Mating success of males initially increased after the first mating, but then males became ‘exhausted’ in later matings; their mating success decreased with the number of prior matings. The fertility of females was affected by mating with multiple‐mated males. The study suggests that male mating history affects the fitness of male and female D. rapae.     

Male Condition, Female Choice, and Extreme Variation in Repeated Mating in a Scaly Cricket, Ornebius aperta (Orthoptera: Gryllidae: Mogoplistinae)

Mating in the scaly cricket Ornebius aperta often includes the transfer of many spermatophores to individual females during extended copulatory interactions. We manipulated male condition in staged matings to determine whether this could explain variation in the number of repeated copulations seen across pairs. Males on a high nutrient diet were in good condition, were more likely to mate repeatedly, and transferred more spermatophores on average than low-diet males (in poor condition). High-diet males were more likely to produce a vibratory signal that increased female receptivity to repeated mating attempts. Courtship and copulatory interactions were always terminated by females, and in every case males had already formed a spermatophore when deserted by females. We conclude that variation in male repeated mating success may be due to female choice rather than an inability or unwillingness of low-diet males to produce spermatophores.     

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   

Effects of size at metamorphosis on stonefly fecundity, longevity, and reproductive success

Many organisms with complex life cycles show considerable variation in size and timing at metamorphosis. Adult males of Megarcyssignata (Plecoptera: Perlodidae) are significantly smaller than females and emerge before females (protandry) from two western Colorado streams. During summer 1992 stoneflies from a trout stream emerged earlier in the season and at larger sizes than those from a colder fishless stream, and size at metamorphosis did not change over the emergence period in either stream. We performed two experiments to determine whether variation in size at metamorphosis affected the fecundity, reproductive success and longevity of individuals of this stonefly species and if total lifetime fecundity was affected by the number of matings. In the first experiment, total lifetime fecundity (eggs oviposited) was determined for adult females held in small plastic cages in the field. Males were removed after one copulation, or pairs were left together for life and allowed to multiply mate. Most copulations occurred in the first few days of the experiment. Females in treatments allowing multiple matings had significantly lower total lifetime fecundity and shorter adult longevity than females that only mated once. Multiple matings also reduced longevity of males. Fecundity increased significantly with female body mass at emergence, but only for females that mated once. While multiple matings eliminated the fecundity advantage of large female body size, number of matings did not affect the significant positive relationship between body mass at metamorphosis and longevity of males or females. In a second experiment designed to determine if body mass at emergence affected male mating success, we placed one large and one small male Megarcys in an observation arena containing one female and recorded which male obtained the first mating. The large and the small male had equal probabilities of copulating with the female. Copulations usually lasted all night, and the unmated male made frequent, but unsuccessful attempts to take over the copulating female. Our data suggest that selection pressures determining body size at metamorphosis may operate independently on males and females, resulting in evolution of sexual size dimorphism, protandry, and mating early in the adult stage. We emphasize the importance of interpreting the fitness consequences of larval growth and development on the timing of and size at metamorphosis in the context of the complete life cycle. Received: 1 July 1997 / Accepted: 12 November 1997     

Limits to Nuptial Gift Production by Male Fireflies, Photinus ignitus

Males of diverse insect species provide females with nuptial gifts, and limits on males' ability to produce these gifts may influence courtship behavior and mating systems. In the firefly Photinus ignitus, males transfer a complex spermatophore to females during mating. We provided firefly males unlimited access to responsive females to examine whether spermatophore production limits male mating success. Male spermatophore mass decreased significantly across sequential matings, and the percentage of successful matings declined during the second half of each male's life span. Male body mass explained a significant proportion of variation in size of the first spermatophore produced by P. ignitus males, but this relationship disappeared with second spermatophores. This study indicates that males' ability to produce spermatophores declines over their lifetime and that limits on nuptial giftproduction can constrain male mating success in Photinus fireflies.     

Behavioral and reproductive effects of ultrasound on the Indian meal moth, Plodia interpunctella

The daily activity patterns of adult movement, female calling, and mating of the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), were examined both in the absence and presence of ultrasound. Moths were exposed to ultrasound from a commercial ultrasonic device (Cix 0600) that produces constant sound patterns, and from a device developed at Kansas State University (KSU device) that produces random sound patterns. Daily activity patterns of adult movement, female calling, and mating followed a similar trend in the absence or presence of ultrasound. Female calling and mating, both in the absence and presence of ultrasound, primarily occurred during scotophase (21.00–07.00 hours). Ultrasound from the two devices significantly reduced the frequency of female calling and mating relative to unexposed moths. Consequently, the number of spermatophores transferred by males to females and egg production were lower in females exposed to ultrasound compared with unexposed females. In the absence of ultrasound, female P. interpunctella mated 2.9 times, resulting in 2.8 spermatophores/female. In the presence of ultrasound from the Cix 0600 device, a female mated 2.1 times and had 1.7 spermatophores. Corresponding values for the KSU device were 1.9 and 1.4, respectively. In the absence of ultrasound, 78% of the matings lasted 30–90 min, whereas in the presence of ultrasound 45–58% of the matings lasted either less than 30 min or more than 90 min. Moths exposed to ultrasound laid 96–130 eggs female^?1 compared with 229 eggs female^?1 for unexposed moths. Ultrasound did not affect the pre‐oviposition period and adult longevity of P. interpunctella.     

Alternative male mating behaviors dependent on relative body size in captive oval squid Sepioteuthis lessoniana (Cephalopoda, Loliginidae)

We observed the reproductive behavior of the oval squid Sepioteuthis lessoniana in captivity. The male used three different mating behaviors: male-parallel (MP), male-upturned (MU) and sneaking. Male competition over females frequently occurred before and during the female egg-laying period, and the outcome of most fights depended on male body size. Larger males guarded their partners from other males and performed MP mating during the egg-laying period of the paired females. In contrast, there was no pairing and mate guarding in MU mating and sneaking, which were adopted by smaller subordinate males as alternative tactics outside female egg-laying period and during the period, respectively. MP matings were 95% successful, but more than half of MU matings were unsuccessful. Higher mating success in MP mating was achieved through pairing, whereas males in MU mating were less successful because mating attempts without pair formation were often foiled by escape of the female. Sneaking was successful in all cases but occurred less frequently. Spermatophores were attached at the opening of the oviduct in MP mating, whereas they were attached around the female buccal membrane in MU mating and sneaking. Considering the route of egg transportation, higher fertilization success can be expected in MP mating because of the advantageous location of the attached spermatophores. Our results suggest that MP mating is used by larger, paired males during the female egg-laying period, and that MU mating and sneaking are alternative tactics adopted by smaller, subordinate males. These alternative mating behaviors would be conditional strategy dependent on relative body size, because some individual males displayed both MP and MU mating behaviors.     

Indicators of recent mating success in the pipevine swallowtail butterfly (Battus philenor) and their relationship to male phenotype

A key determinant of the intensity of sexual selection acting on a trait is how variation in that trait is related to variance in reproductive success of individuals. This connection compels efforts to assess lifetime mating number and how it varies among individuals in a population. In the Lepidoptera, female mating success can be assessed relatively easily by counting by the number of spermatophores in the female’s copulatory sac but male mating success in the field can often only be documented by observing copulations. Here we report a method for identifying whether or not males have recently mated that relies on the effect of mating on the appearance of the male’s reproductive tract in the pipevine swallowtail, Battus philenor. In this species laboratory experiments reveal that during mating, components of a male’s reproductive tract become shorter, decrease in mass, and change in appearance, irrespective of male age. These changes persist for at least two days after mating. After documenting these indicators of recent mating, we examined the reproductive tract of 68 field-caught males and found that twelve (17.6%) showed strong evidence of having mated recently. We found that older males were more likely to have recently mated. In addition, the color of the dorsal hindwing, a feature that females use in mate choice, was significantly greener in males, that according to our criteria, had recently-mated than in males that had not.     

Free mutual mate preferences in house mice affect reproductive success and offspring performance

When social constraints on the expression of mate preferences are absent, variation in offspring viability is predicted to favour females and males that display mate preferences. Earlier studies showed that female and male house mice, Mus domesticus, tested individually and mated with preferred (P) partners had higher reproductive success and better progeny performance than individuals mated with nonpreferred (NP) partners. Here we tested the effects of mutual mate preferences on reproductive success, offspring viability and performance. We conducted mate preference tests and created four types of reproductive pairings. One involved females and males that preferred each other (P-P); the second type had females that preferred the male but the male did not prefer the female (P-NP); the third had females that did not prefer the male but the male did prefer the female (NP-P). The last set consisted of females and males that did not prefer each other (NP-NP). We measured components of fitness for breeders (reproductive success) and offspring viability (birth-to-weaning viability and weight variation) as well as measures of offspring performance. There were no statistical differences in reproductive success of breeders or offspring viability and quality (weight variation) among the four types of pairings. There were, however, consistent differences between P-P versus NP-NP matings. The number of pups weaned, time to first litter, birth-to-weaning viability, pup body weight at birth and weaning, and the growth rates for pups of both sexes were consistently greater for progeny from P-P matings than NP-NP matings. Significant differences occurred among the four mating types in dominance of sons during aggression trials, nest construction and predator avoidance. Progeny from P-P matings displayed behaviour associated with higher fitness more often than progeny from NP-NP matings. These data show that breeders produce more highly competent progeny, most likely to survive, when social constraints on the expression of mate preferences in both sexes are relaxed.Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

Attractiveness and competitiveness of irradiated light brown apple moths

The sterile insect technique (SIT) potentially provides a socially acceptable approach for insect eradication of new pest incursions. The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), was discovered in Berkeley (CA, USA) in 2006, leading to an incursion response that included this technology. In this study, we assessed factors affecting mating success from a bisex release of irradiated moths: effects of radiation dose on male multiple mating, male flight competition, female sex pheromone titre and attractiveness of irradiated females to males, and identification of successful mating in vineyards of either irradiated or wild males (identified by isotope analysis of spermatophores from sentinel females). There was a significant negative relationship between male radiation dose and mating frequency. In head‐to‐head flights of irradiated males against non‐irradiated males to a pheromone lure in a wind tunnel, irradiated males reached the lure first only 31% of the time. With increasing radiation dose, the production of the major sex pheromone component in females, (E)‐11‐tetradecenyl acetate, dropped, from 0.7 ± 0.1 ng per female in non‐irradiated females to 0.2 ± 0.07 ng per female when irradiated at 300 Gy. Male catch was reduced to 11% of control females in traps containing females irradiated at 300 Gy. Isotope analysis of spermatophores found in the bursa copulatrix of females indicated that mating success of irradiated males inside the live (entry‐only) traps containing virgin females was lower (13.1 ± 3.3%) than suggested by male catch (21.2 ± 3.8%) in pheromone traps, the current standard for assessing field competitiveness. Impacts of irradiation on male and female moth fitness should be taken into account to improve estimates of irradiated to wild male E. postvittana overflooding ratios needed for population suppression.     

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.     

Delayed mating and its cost to female reproduction in the butterfly,Eurema hecabe

The timing of mating of females under semi-natural condition, male ejaculate production and their effects on female fecundity were examined inEurema hecabe. Age of the first mating of females varied, and the number of matings increased with age. Male spermatophore production depended on age and body mass. The spermatophore mass at the second mating depended only on the interval between the first and second matings. The timing of the first mating and the spermatophore mass did not affect female fecundity. The timing of mating of females relative to the role of male spermatophores in female fecundity and male mating strategy are discussed.     

Male Remating Behavior and Its Effect on Female Reproductive Fitness in Cnephasia jactatana Walker (Lepidoptera: Tortricidae)

Male remating behavior and its effect on the female reproductive fitness of a New Zealand leafroller, Cnephasia jactatana, were investigated in the laboratory. With a recovery period of at least 24 h between matings, most males were able to mate four times and only about 25% could mate six times during their lifespan. Only 5% of males managed to mate twice within 1 day. Mated males transferred 31–51% smaller spermatophores than virgin males. When mating with a mated male, the female was subject to a 20–51% and 23–51% reduction in fecundity and fertility, respectively. With the increasing number of matings her partner had achieved before mating with her, the female's fertility declined significantly faster than fecundity. Courtship period and mating duration remained similar regardless of the male's mating history but males required increasingly longer latency to start courtship display with the increasing number of matings achieved.     

The mating strategy and reproductive performance of Agriphila aeneociliella (Lepidoptera: Crambidae), a new insect pest of wheat in China

1. The Eastern Grass‐veneer Agriphila aeneociliella (Eversmann) (Lepidoptera: Crambidae) is a serious stem‐feeding pest of wheat crops that has become established in China in recent years. A better understanding of the mating strategy and reproductive performance of A. aeneociliella could improve integrated pest management programmes against this newly established species by disturbing its behaviour and reducing its reproduction potential. Based on ethological and reproductive biological approaches, the mating and reproductive performances of A. aeneociliella were investigated.
2. Unlike the common nocturnal lepidopterans, the mating rhythm of A. aeneociliella moths showed a marked diurnal pattern. The female courtship rhythm and the mating rhythm reached peaks within the first 2 h after the onset of photocycle.
3. The mating success rate of monogamous pairs was 55.6%, whereas the male‐biased sex ratio (2♂:1♀) increased the mating rate (72.2%) and the female‐biased ratio (1♂:3♀) led to the lowest mating rate (27.8%).
4. Both females and males were able to mate twice. The duration of copulation decreased substantially with male mating frequency, whereas, when a previously mated female was paired with a virgin male, fecundity significantly increased. Monogamous couples who mated only once in their lives have the highest hatchability (97.13 ± 0.49%).

     

Spermatophore and Sperm Allocation in Males of the Monandrous Butterfly Pararge aegeria: the Female’s Perspective

In insects, spermatophore production represents a non‐trivial cost to a male. Non‐virgin males have been shown to produce small spermatophores at subsequent matings. Particularly in monandrous species, it may be an issue to receive a sufficiently large spermatophore at the first and typically only mating. Females of the monandrous Speckled wood butterfly Pararge aegeria (L.) produce fewer offspring after mating with a non‐virgin male. After mating, females spend all their active time selecting oviposition sites and typically ignore other males. Here, we show that females did not discriminate between a virgin male and a recently mated male in our laboratory experiments. We demonstrate that the number of eupyrene sperm bundles relative to spermatophore mass differed with subsequent male matings. Males transferred a significantly smaller spermatophore after the first copulation, but the spermatophore mass did not decrease further with subsequent matings. However, the number of eupyrene sperm bundles decreased linearly. Therefore, there was proportionally more eupyrene sperm in the male’s second spermatophore compared with the first and the later spermatophores. Such a pattern has been shown in polyandrous species. Hence, it suggests that differences in sperm allocation strategy between polyandrous and monandrous butterflies may be quantitative rather than qualitative. There was also a tendency for females that had mated with a recently mated male to have higher propensity to remate than did females that had mated with a virgin male. We discuss the results relative to the mating system in P. aegeria, including female remating opportunities in the field and male mate‐locating behaviour.     

Mating frequency and reproductive success in an income breeding moth,Mnesampela privata

The frequency of mating in insects is often an important determinant of female reproductive output and male sperm competition. In Lepidoptera that provide male nutrients to the female when mating, it is hypothesized that polyandry may be more prevalent. This is thought to be especially so among species described as income breeders; that is, in species who do not derive all their nutrients for reproductive output entirely from the resources obtained during the larval stage. We selected the geometrid moth, Mnesampela privata (Guenée) (Lepidoptera: Geometridae), to examine this hypothesis further. We found this species was best characterized as an income breeder with female weight on emergence positively correlated with total egg load but not with the number of eggs laid. Further, in accord with income breeders, females emerged with a partially developed egg load and lifetime fecundity was positively correlated with the number of oviposition days. However, in the laboratory we found that incidence of repeated matings or polyandry was rare. When moths were paired singly over their lifetime, only 4% of mated females multiple mated. When females were paired with three males concurrently, female mating success increased from 60 to 81% with multiple mating among mated females increasing to just 15%. Dissection of wild caught M. privata found that polyandry levels were also low with a maximum of 16.4% of females collected at any one time being multiple mated. In accord with theory, mating significantly increased the longevity of females, but not of males, suggesting that females acquire essential resources from male ejaculates. Despite this, multiple mated females showed a trend toward decreasing rather than increasing female reproductive output. Spermatophore size, measured on death of the female, was not correlated with male or female forewing length but was negatively correlated with the number of fertile eggs laid and female longevity. Smaller spermatophore width may be related to uptake of more nutrients by the female from a spermatophore. We discuss our findings in relation to income breeding and its relationship to polyandry in Lepidoptera.