玉米螟赤眼蜂雄性生殖力的研究

根据膜翅目寄生蜂未受精的卵发育为雄性个体,受精卵发育成雌性个体这一性别决定机制,考察了玉米螟赤眼蜂雄蜂生殖力的大小,探讨了雄蜂授精能力与个体大小、年龄及交配次数之间的关系。结果表明,玉米螟赤眼蜂雄蜂在羽化时或羽化后很短的时间内其精巢就已发育成熟,成虫期不再形成新的精子。雄蜂在羽化后立即可与雌蜂进行交配,在雌蜂过量的情况下,24 h内就可能将体内的精子或精液消耗尽,24 h后的雄蜂虽能与雌蜂继续交尾,但雌蜂所繁育的子代中未见有雌性个体。同一雄蜂能与多头雌蜂进行交尾,授精8～23头雌蜂,平均能繁育出346.15头雌性后代。雄蜂的授精能力与交配次数密切相关,授精量随交配次数增加而逐渐下降。首次交配时,雄蜂能给雌蜂提供较多的精子,约能繁育出58.85头雌性后代,但随着交配次数的增加,雄蜂向雌蜂输送的精子越来越少,10次交配之后,雄蜂所能授精、繁育的子代雌性数将不超过10头。以后足胫节长度表示个体大小时,体型较大的雄性个体进行多次交配的能力强,能繁育更多的雌性后代。     

一种斑翅果蝇寄生蜂的交配行为观察及雄虫交配次数对繁殖的影响

【目的】明确一种斑翅果蝇寄生蜂Trichopria drosophilae的交配行为以及雌雄蜂的交配次数对后代的影响。【方法】在室内对斑翅果蝇寄生蜂的交配行为进行观察,记录该蜂在交配行为中所出现的求偶行为、交尾前期行为、交尾行为和交尾完毕的动作及持续时间。测定寄生蜂各交配次数下的雌蜂寿命、后代出蜂总量和后代性比。【结果】寄生蜂的交配过程包括以下几个阶段:求偶,雄蜂逐渐靠近雌虫、追逐雌蜂并震动翅膀,直至爬上雌虫背部整个过程持续(50.47±85.01)s。交尾前期,雄虫头部从雌蜂的两触角中间伸出,并将触角从雌虫触角两侧向中间有规律的触碰雌虫触角,直至雌蜂打开生殖孔,整个过程持续(43.73±13.97)s。交尾,雄蜂将雄性交配器插入雌性生殖孔整个过程持续(36.28±11.03)s。交尾后期,雌虫左右甩动腹部2~3次,主动与雄虫分离整个过程持续(8.95±3.40)s。观察结果显示,雌虫一生只能交配一次,雄蜂一生交配次数在(16.54±1.37)次,最多达到19次(N=10),雄虫的交配次数对与之交配的雌蜂的寿命和后代总量无显著影响。雄蜂的交配次数对雌性后代的性比有显著影响。【结论】该寄生蜂的交配过程主要分为雄虫求偶、交尾前期、交尾、交尾后期等阶段。求偶和交尾前期阶段主要行为是雄虫追逐雌蜂、爬上雌虫背部并用触角摩擦雌虫触角。交尾阶段主要行为是雄蜂交配器插入雌性生殖孔。交尾后期主要行为是雌蜂将雄蜂甩开,是雌虫唯一主动发起的行为。随着雄蜂交配次数增加,雌蜂后代雌/雄性比降低。     

家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对果蝇蛹的寄生比较

【目的】蝇蛹金小蜂Pachycrepoideus vindemmiae(Rondani)是杨梅园等果园果蝇类害虫蛹期常见寄生蜂种类,在对果蝇类害虫的生物防治上具有重要价值。本文旨在探讨使用家蝇蝇蛹为替代寄主繁育蝇蛹金小蜂的方法。【方法】探讨分别以家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对家蝇和果蝇蝇蛹的选择性,并比较了在两种寄主上繁育的蝇蛹金小蜂在大小、寿命、产卵期、后代产量和性比等方面的差异。【结果】结果表明与果蝇蛹相比,家蝇蛹明显较大,在家蝇蛹上发育的蝇蛹金小蜂后代个体也明显较大;家蝇蛹和果蝇蛹发育的寄生蜂雌蜂寿命为(13.4±4.11)和(3.94±2.49)d、产卵期分别为(11.4±4.11)和(3.13±2.42)d、单头雌蜂后代雌蜂数量分别为(34.31±31.83)和(7.88±3.58)头,在家蝇蛹上繁育的寄生蜂明显具有较长的寿命和产卵期、更多的雌雄蜂后代数量;在对家蝇蛹和果蝇蛹的选择上,繁育自家蝇和果蝇的蝇蛹金小蜂雌蜂选择频率的差异不大。【结论】利用家蝇蛹繁殖的蝇蛹金小蜂在寄生果蝇蛹时具有更大优势,在繁殖蝇蛹金小蜂控制杨梅园等果蝇的为害时,可以选择家蝇蛹作为替代寄主。     

蝇蛹金小蜂对家蝇蛹的寄生策略

蝇蛹金小蜂Pachycrepoideus vindemmiae Rondani是家蝇Musca domestica蛹期常见寄生蜂种类。本文探讨蝇蛹金小蜂对寄主日龄的选择策略以及该寄生蜂的寿命、产卵历期和后代数量等规律。结果表明寄生蜂可利用各日龄的蝇蛹,寄生高龄期蝇蛹时,寄生蜂后代产量显著降低,既未出蜂也未出蝇的死亡蝇蛹比例显著增加;寄生蜂寿命为(11.89±6.99)d,产卵历期为(9.58±6.67)d,单个雌蜂后代产量为(33.74±18.08)头,雄性后代的发育历期显著短于雌性后代,随着寄生蜂产卵历期的延长,寄生蜂后代产量下降,雄性后代比例增加。     

寄主大小及寄生顺序对蝇蛹佣小蜂寄生策略的影响

寄主大小模型认为寄生蜂后代性比与寄主大小相关,寄生蜂倾向于在大寄主上产出更多雌性后代,在小寄主上产出更多雄性后代.探讨了以家蝇蛹为寄主时,蝇蛹佣小蜂后代产量和性比变化;单次寄生情况下,寄主大小及寄生顺序对寄生蜂后代性比等影响.结果表明,蝇蛹佣小蜂的产卵期为(8.93±3.34)d,单头雌蜂能产雌性后代(34.11±16.34)头和雄性后代(11.04±8.87)头,且雄性百分比为0.24±0.11.随成蜂日龄的增大,寄生蜂产生雄性后代的比率显著增加.蝇蛹佣小蜂在寄生家蝇蛹时,会优先选择寄生个体较大的蛹;在单次寄生的情况下,蝇蛹佣小蜂倾向于在较大的家蝇蛹内产出更多的雌性后代.     

菜粉蝶蛹体型大小对蝶蛹金小蜂后代数量、性比及体型大小的影响

为检验“寄主体型大小-质量假说”,采取饥饿方法处理菜粉蝶(Pieris rapae)高龄幼虫,以获得体型大小(用体质量表示)差异大于同一自然地理种群内个体间差异的寄主蛹,然后供聚寄生蜂-蝶蛹金小蜂(Pteromalus puparum)寄生,观察寄生蜂在不同大小寄主蛹内的后代数量、性比以及体型大小。结果表明,蝶蛹金小蜂1次攻击产出的后代蜂数随寄主蛹体质量增加而显著增多,蛹中平均出蜂314.97头·g^-1。蝶蛹金小蜂后代的雌性比例随寄主蛹质量的增大而显著提高,后代雌蜂和雄蜂的体型大小(后足胫节长度)均随寄主蛹质量的增大而显著增大。可见,蝶蛹金小蜂母蜂能够根据寄主蛹质量来调整后代数量和性比,以使后代适应度最大化。最后,就蝶蛹金小蜂产卵策略及其影响因素进行了讨论。     

寄主大小对蝇蛹俑小蜂Spalangia endius(Walker)产卵选择和发育的影响

【背景】对寄生蜂与寄主之间关系的研究是寄生蜂有效利用的基础。寄生蜂雌蜂通常选择最适于子代蜂发育的寄主进行产卵。【方法】在室内26℃条件下,研究了橘小实蝇蛹体型大小对蝇蛹俑小蜂产卵和生长发育的影响。采用饥饿方法处理3龄橘小实蝇幼虫以获得体型大小(用体质量表示)差异较大的寄主蛹,供寄生蜂选择寄生。【结果】蝇蛹俑小蜂显著偏好寄生体型中等的寄主蛹,然而,随着寄主体型的增大,后代雌性比率增大,且寄主蛹个体大小与后代雌蜂体型大小存在显著的正相关;橘小实蝇蛹个体大小对蝇蛹俑小蜂后代发育历期和寿命无显著影响。【结论与意义】蝇蛹俑小蜂雌蜂能够根据寄主蛹质量来调整后代数量和性比,以使后代适应度最大化。     

不同方法处理的家蝇蛹对蝇蛹金小蜂繁殖的影响

通过适当方法处理寄主并长期保存,是大量繁殖寄生蜂的重要途径.蝇蛹金小蜂是多种有害蝇类的蛹期重要寄生蜂,在生物防治上具有重要价值.本文探讨了蝇蛹金小蜂对-20℃冷冻、6℃冷藏和二氧化碳窒息处理1、3和30 d的家蝇蛹以及热处死和热处死后冷藏保存30 d家蝇蛹的寄生能力.结果表明:蝇蛹金小蜂可以利用上述蝇蛹,且其后代在胫节长度上均与源自新鲜蛹的寄生蜂胫节长度无显著差异;但除冷冻方法外,寄生蜂后代产量均随寄主保存时间的延长而降低.在保存30 d的前提下,冷冻方法保存的寄主上寄生蜂后代最多.表明在大量繁殖蝇蛹金小蜂时,可以利用冷冻等方法对寄主进行处理并保存.     

聚寄生性蝶蛹金小蜂雌蜂体型大小对产卵策略的影响

在寄生蜂行为生态学研究中, 通常将寄主体型大小作为寄主品质的主要性状来探究寄生蜂的搜寻行为机理, 而忽略寄生蜂体型大小的意义。为揭示聚寄生蜂雌蜂体型大小对其产卵决策的影响, 在严格控制寄主菜粉蝶Pieris rapae蛹体型大小（体重）的情况下, 于室内观察了不同体型大小的蝶蛹金小蜂Pteromalus puparum雌蜂的产卵行为, 并调查了子代蜂数量（窝卵数）、 性比和体型大小的变化。结果表明： 雌蜂在寄主上的驻留时间随其自身体型增大而缩短, 但随寄主体重增大而延长。窝卵数和余卵量受到雌蜂体型大小的显著影响, 均随雌蜂体型增大而显著增加（P<0.05）; 但子代蜂性比不受雌蜂体型大小的显著影响 (P>0.05)。子代雌、 雄性体型大小均与雌蜂体型大小无关, 但子代雌蜂体型随寄主体重增大而增大。结果证实, 雌性蝶蛹金小蜂体型大小影响其部分产卵决策。因此, 在建立聚寄生蜂产卵决策模型中应考虑雌蜂体型大小这一重要变量因素。     

西双版纳鸡嗉果榕内一种非传粉小蜂的性比调节

对西双版纳广泛分布的鸡嗉果榕(Ficus semicordata)雄树上寄生的一种非传粉榕小蜂Apocryptophagus sp.进行控制梯度放蜂实验,结合产卵行为、交配行为观察,定量研究了该种非传粉榕小蜂的性比率.结果表明: Apocryptophagus sp.雌蜂在传粉榕小蜂(Ceratosolen gravelyi)产卵后的第3天开始访问榕果,从果外完成产卵,产卵时间持续2 d左右.发育成熟以后,其雄蜂几乎与传粉榕小蜂雄蜂同时羽化,雄蜂咬开寄生有其雌蜂的瘿花并进行交配,雌蜂交配后从瘿花内羽化出来离开榕果,去寻找新的处于接受期的榕果,而雄蜂一直留在其寄生的榕果内直至死亡.后代性比与局域配偶竞争理论预测一致：性比偏雌,随着在同一榕果产卵的繁殖雌蜂数量的增加,后代性比上升;同时,单个榕果内的后代数量也上升,而平均后代数量却显著下降.在个体水平上,当1头雌蜂在榕果上产卵时,后代性比与后代数量呈显著的负相关关系.     

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.     

Reproductive costs of mating with a sibling male: sperm depletion and multiple mating in Cephalonomia hyalinipennis

Polygynous parasitoid males may be limited by the amount of sperm they can transmit to females, which in turn may become sperm limited. In this study, I tested the effect of male mating history on copula duration, female fecundity, and offspring sex ratio, and the likelihood that females will have multiple mates, in the gregarious parasitoid Cephalonomia hyalinipennis Ashmead (Hymenoptera: Bethylidae: Epyrinae), a likely candidate for sperm depletion due to its local mate competition system. Males were eager to mate with the seven females presented in rapid succession. Copula duration did not differ with male mating history, but latency before a first mating was significantly longer than before consecutive matings. Male mating history had no bearing on female fecundity (number of offspring), but significantly influenced offspring sex ratio. The last female to mate with a given male produced significantly more male offspring than the first one, and eventually became sperm depleted. In contrast, the offspring sex ratio of first‐mated females was female biased, denoting a high degree of sex allocation control. Once‐mated females, whether sperm‐depleted or not, accepted a second mating after a period of oviposition. Sperm‐depleted females resumed production of fertilized eggs after a second mating. Young, recently mated females also accepted a second mating, but extended in‐copula courtship was observed. Carrying out multiple matings in this species thus seems to reduce the cost of being constrained to produce only haploid males after accepting copulation with a sperm‐depleted male. I discuss the reproductive fitness costs that females experience when mating solely with their sibling males and the reproductive fitness gain of males that persist in mating, even when almost sperm‐depleted. Behavioural observations support the hypothesis that females monitor their sperm stock. It is concluded that C. hyalinipennis is a species with a partial local mating system.     

Why do sperm-depleted parasitoid males continue to mate?

Insect males of several parasitoid species have limited amountof sperm at emergence and experience sperm depletion when mateacquisition rate is high, suggesting that sperm production andstorage could be a limiting factor for male's fitness. Sperm-depletedmales of the parasitoid wasp Trichogramma evanescens continueto mate, and the impact of this behavior on sperm storage byfemales has been studied. Virgin females T. evanescens stored50.6 ± 13.1 (Mean ± SD) sperm when mating firstwith a virgin male. However, when these females mated firstwith a sperm-depleted male and then with a virgin male, theystored only 18.9 ± 7.8 sperm, indicating that matingwith a sperm-depleted male has a cost and limits sperm acquisitionfrom fertile males. Following a mating with a sperm-depletedmale, females had to mate with three virgin males to restoretheir sperm supply confirming that additional mating enabledthe female to store a limited number of sperm. According toour results, by continuing to mate, sperm-depleted males donot prevent mates from copulating again but they decrease theirability to store other male's sperm. Continuing to mate couldbe a strategy to increase the relative fitness of sperm-depletedmales.     

Mating with sperm-depleted males does not increase female mating frequency in the parasitoid Lariophagus distinguendus

Sexual conflicts due to divergent male and female interests in reproduction are common in parasitic Hymenoptera. The majority of parasitoid females are monandrous, whereas males are able to mate repeatedly. Thus, accepting only a single mate might be costly when females mate with a sperm‐depleted male, which may not transfer a sufficient amount of sperm. In the present study, we investigated the reproductive performance in the parasitoid Lariophagus distinguendus Först. (Hymenoptera: Pteromalidae) and studied whether mating with experimentally sperm‐depleted males increases the tendency of females to remate. Males were able to mate with up to 17 females offered in rapid succession within a 10‐h test period. The resulting female offspring, as an indirect measure of sperm transfer, remained constant during the first six matings and then decreased successively with increasing number of copulations by the males. Experimentally sperm‐depleted males continued to mate even if they transferred only small amounts or no sperm at all. Unlike males, the majority of females mated only once during a 192‐h test period. A second copulation was observed only in a few cases (maximum 16%). The frequency of remating was not influenced by the mating status of the first male the females had copulated with, suggesting that these events are not controlled by sperm deficiency of the females. Furthermore, we investigated male courtship behaviour towards mated females. Male courtship intensity towards mated females decreased with increasing time. However, females that had mated with an experimentally sperm‐depleted male did not elicit stronger or longer‐lasting behavioural responses in courting males than those that had mated with a virgin male. As the observed behaviours in L. distinguendus are known to be elicited by a courtship pheromone, these results suggest that females no longer invest in pheromone biosynthesis after mating (as indicated by ceasing behavioural responses of courting males), irrespective of whether they have received a sufficient amount of sperm or not. We discuss the results with respect to a possible mating strategy of sperm‐depleted males.     

The evolution of polyandry: an examination of the genetic incompatibility and good‐sperm hypotheses

I have examined the adaptive significance of polyandry using the Australian field cricket Teleogryllus oceanicus. Previous studies of polyandry have examined differences in offspring production by females mated multiply to a single male or females mated multiply to different males. Here I combine this approach with a study of parentage of offspring produced in the later group. Females mated to two different males had a higher proportion of their eggs hatching than did females mating twice with a single male. Offspring fitness parameters were not effected. There was little evidence to suggest that females elevate their hatching success via fertilizing their eggs with sperm from genetically compatible males. Although the average paternity points towards random sperm mixing, there was considerable individual variation in sperm competition success. Patterns of parentage were consistent across females mating twice or four times. Sperm competition success was not related to offspring viability or performance. Thus, the notion that competitively superior sperm produce competitively superior offspring is not supported either. The mechanism underlying increased hatching success with polyandry requires further study.     

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.     

How multiple mating by females affects sexual selection

Multiple mating by females is widely thought to encourage post-mating sexual selection and enhance female fitness. We show that whether polyandrous mating has these effects depends on two conditions. Condition 1 is the pattern of sperm utilization by females; specifically, whether, among females, male mating number, m (i.e. the number of times a male mates with one or more females) covaries with male offspring number, o. Polyandrous mating enhances sexual selection only when males who are successful at multiple mating also sire most or all of each of their mates'' offspring, i.e. only when Cov_♂(m,o), is positive. Condition 2 is the pattern of female reproductive life-history; specifically, whether female mating number, m, covaries with female offspring number, o. Only semelparity does not erode sexual selection, whereas iteroparity (i.e. when Cov_♀(m,o), is positive) always increases the variance in offspring numbers among females, which always decreases the intensity of sexual selection on males. To document the covariance between mating number and offspring number for each sex, it is necessary to assign progeny to all parents, as well as identify mating and non-mating individuals. To document significant fitness gains by females through iteroparity, it is necessary to determine the relative magnitudes of male as well as female contributions to the total variance in relative fitness. We show how such data can be collected, how often they are collected, and we explain the circumstances in which selection favouring multiple mating by females can be strong or weak.     

SPERM COMPETITION AND THE EVOLUTION OF NUPTIAL FEEDING BEHAVIOR IN THE CRICKET,GRYLLODES SUPPLICANS (WALKER)

The pattern of sperm predominance in doubly mated female crickets, Gryllodes supplicans, was investigated using a radiation-sterility technique. Female G. supplicans made significant use of sperm from both males in fertilizing eggs; overall, first males to mate enjoyed a small advantage, fertilizing about 60% of the offspring produced subsequent to the second mating. The combined use of the sperm of both males in fertilizing eggs occurred soon after the second mating; evidently, mixing of ejaculates within a female's spermatheca does occur. Male G. supplicans provide females with a nuptial gift, the spermatophylax, which influences the time at which a female removes the externally attached sperm-ampulla; this in turn determines the quantity of sperm that is transferred. Moreover, the degree of sperm precedence achieved by a male may be positively related to the time at which the female removes his sperm ampulla. Thus males, by feeding females, ensure not only that a sufficient number of sperm are transferred to fertilize all of a female's eggs, but also may increase the certainty of their paternity. In mating systems in which females control sperm transfer and paternity is influenced by numbers of sperm (i.e., numerical sperm competition), an increase in prezygotic investment in females may be an adaptive male response.     

Polyandrous females provide sons with more competitive sperm: Support for the sexy‐sperm hypothesis in the rattlebox moth (Utetheisa ornatrix)

Given the costs of multiple mating, why has female polyandry evolved? Utetheisa ornatrix moths are well suited for studying multiple mating in females because females are highly polyandrous over their life span, with each male mate transferring a substantial spermatophore with both genetic and nongenetic material. The accumulation of resources might explain the prevalence of polyandry in this species, but another, not mutually exclusive, possibility is that females mate multiply to increase the probability that their sons will inherit more‐competitive sperm. This latter “sexy‐sperm” hypothesis posits that female multiple mating and male sperm competitiveness coevolve via a Fisherian runaway process. We tested the sexy‐sperm hypothesis by using competitive double matings to compare the sperm competition success of sons of polyandrous versus monandrous females. In accordance with sexy‐sperm theory, we found that in 511 offspring across 17 families, the male whose polyandrous mother mated once with each of three different males sired significantly more of all total offspring (81%) than did the male whose monandrous mother was mated thrice to a single male. Interestingly, sons of polyandrous mothers had a significantly biased sex ratio of their brood toward sons, also in support of the hypothesis.     

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.