二化螟的多次交配及其对雌蛾产卵量的影响

【目的】利用性诱防控和监测水稻二化螟Chilo suppressalis的有效性在田间已经得到认可。但雄蛾具有多次交配能力,致使性诱防治二化螟的应用策略一直存在争论。本研究的目的是探索二化螟雄蛾的多次交配及其对雌蛾繁殖力的影响,认识性诱防控害虫的机理。【方法】利用行为学方法调查了雌雄蛾以不同比例配对(1∶1, 4∶1和10∶10)时雄蛾的交配次数和交配持续时间,并结合解剖学方法,观察分析了二化螟雄蛾的交配次数对精巢、交配囊和精包大小以及雌蛾产卵量的影响。【结果】二化螟雌雄蛾按1∶1配对时,交配雄蛾和多次交配雄蛾的比例分别为74.0%和36.0%,平均交配1.7次,首次交配主要发生在0-1日龄,绝大部分具有多次交配能力的雄蛾的首次交配发生在0-1日龄。雌雄蛾按4∶1配对时,交配雄蛾和多次交配雄蛾的比例分别为69.4%和51.3%,平均交配2.1次,显著高于按1∶1配对。雌雄蛾按10∶10配对时,交配雄蛾和多次交配雄蛾的比例分别为65.5%和37.8%,平均交配1.9次。雄蛾第3次交配的持续时间显著长于第1和2次交配,但是交配1-3次雄蛾的精巢体积无显著差异。与不同交配次数雄蛾进行交配的雌蛾交配囊和精包体积无显著差异,雌蛾产卵量也无显著差异。【结论】二化螟中仅有部分雄蛾能够多次交配,多次交配雄蛾的首次交配主要发生在0-1日龄,部分雄蛾一生都不会交配。研究结果为二化螟的性诱防治提供了理论依据。     

延迟交配对马铃薯块茎蛾繁殖的影响

[目的]为了明确延迟交配对马铃薯块茎蛾Phthorimaea operculella Zeller繁殖的影响.[方法]在室内条件下,设置雌雄延迟交配、雄虫延迟交配和雌虫延迟交配3种处理,观察延迟交配不同天数后马铃薯块茎蛾的交配率、交配持续时间、繁殖力和成虫寿命的变化情况.[结果]在3种延迟交配的情况下,延迟交配5d的交配率均是最低,且与雌虫延迟交配相比,雄虫延迟交配和雌雄虫延迟交配对交配率的影响更明显.延迟交配对卵孵化率和产卵量均有明显的不利影响,其中雌雄延迟交配、雄虫延迟交配、雌虫延迟交配三者的均在延迟交配2d时的产卵量最高,在延迟交配5d时的产卵量最低,且两性延迟交配、雌虫延迟交配之间有显著差异.此外,受到延迟交配的影响雌雄虫寿命均有所增加,并且与单一性别对寿命的影响而言,两性延迟交配对寿命的影响更为明显,与雌虫相比雄虫更容易受到延迟交配的影响.[结论]延迟交配会对马铃薯块茎蛾的繁殖有明显不利的影响,可以对迷向法对马铃薯块茎蛾防治提供一定的参考.     

三叶虫萤的交配与产卵行为

【目的】研究三叶虫萤Emeia pseudosauteri成虫的交配与产卵行为,丰富三叶虫萤的生物学研究,推动三叶虫萤的人工繁育。【方法】采用室内试验与野外观察相结合、仪器拍摄和人工观察相结合的方法研究三叶虫萤的交配与产卵行为。【结果】本文先描述了三叶虫萤成虫交配前雄雄相遇、雌雌相遇、雌雄相遇分别会发生的情况,然后较为详细地描述了交配的过程。交配姿势有上下体位(或称"∠"型)和尾对尾体位(或称"—"型),后者由前者转换而来。雌雄成虫可以多次交配,雄虫有交配干扰和假交配现象。成虫24 h内均有交配现象,交配高峰出现在20:00-22:00(交配率20.8%)和12:00-14:00(交配率15.1%)。雌虫多数喜将卵产在潮湿的苔藓上,卵常聚集成一丛或成簇排列。雌虫可多次产卵,但初次产卵数量最多(高达67.82%),随后产卵量则随产卵次数增加而减少。雌雄虫多次交配后单只雌虫的第一次产卵量[(45±5)粒]多于单次交配后单只雌虫第一次产卵量[(20±4)粒]。雌虫的产卵次数和产卵量与其体重相关,体重越重则其产卵次数和产卵量越多。【结论】三叶虫萤的交配产卵行为与以往报道的萤火虫交配产卵行为很多相似之处,但也有一些特殊行为或规律。     

松墨天牛成虫交配与产卵行为的观察

观察了养虫笼中松墨天牛Monochamus alternatusHope的交配和产卵行为。描述了雌、雄虫在交配过程中的多种行为,雌、雄虫间的交配时间可持续23~540 min,平均约200 min;有重复交配现象,重复交配次数可达2~18次;每次交配持续时间为2~100 s。雌虫背负雄虫,边取食边产卵;也可脱离雄虫单独产卵。雌虫在寄主枝条上咬槽产卵,通常日产卵1~2粒,最多3粒。产卵期的长短和产卵量的多少取决于雌虫个体寿命的长短。     

韭菜迟眼蕈蚊雄虫日龄对其交配能力和雌虫生殖力的影响

为了提高韭菜迟眼蕈蚊性信息素监控水平,本文在25℃、RH70%±5%、光周期L∶D=14∶10的条件下研究韭菜迟眼蕈蚊不同日龄雄虫的交配能力及其对雌虫生殖力的影响。结果表明,未交配雄虫平均寿命4.5d,雌虫4.2d,雌雄成虫的平均寿命无显著差异。雄虫一生最多可交配13次,且随着雄虫日龄增加,雌虫交配成功率逐渐减少。随着雄虫交配经历的增加,雌虫交配的时间延长,最长达97min。雄虫的日龄并不影响与之交配雌虫的产卵量和卵孵化率,但是雄虫的交配经历与雌虫的产卵量和卵孵化率相关,尤其当雄虫交配经历超过8次时,与之交配的雌虫的产卵量和卵孵化率显著下降。研究阐明了韭菜迟眼蕈蚊的生殖行为特征,为其性信息素应用提供了参考。     

水稻二化螟的交配行为

在室内条件下,对水稻二化螟Chilo suppressalis的交配行为及能力进行了研究.结果表明：大多数二化螟雌蛾一生只交配一次,平均0.92次;而雄蛾具有多次交配能力,最多达4次,平均2.72次.二化螟雌蛾的日龄影响其交配率、交配起始时间和持续时间,随二化螟雌蛾日龄的增加,其交配率逐渐下降,交配起始时间逐渐提前,而交配持续时间逐渐上升.相反,二化螟雄蛾日龄对其交配率、交配起始时间和持续时间没有明显影响.交配日龄对二化螟雌蛾的生殖力也存在显著影响,随着二化螟雌蛾交配日龄的增加,雌蛾产卵量下降,卵孵化率降低,产卵期缩短,它们都与雌蛾交配日龄存在显著的负相关;而雌蛾产卵前期和雌蛾寿命随雌蛾交配日龄的增加而延长,与雌蛾交配日龄存在显著的正相关.但二化螟雄蛾交配日龄对雌蛾的生殖力没有明显影响,二化螟雄蛾一生都具有较强的交配繁殖能力.同时,不同交配史的雄蛾与雌蛾交配,对雌蛾的生殖力也没有显著影响.表明二化螟的交配活动是由雌蛾主导控制的.最后,对这些结果在二化螟性信息素防治中应用的可行性进行了探讨.在应用性信息素控制二化螟的实践中,可以在两方面取得实效,一是性信息素可以阻碍雌雄之间正常交配,降低交配率;二是可以推迟二化螟雌虫的交配,使其产卵量和卵孵化率降低.     

扶桑绵粉蚧交配行为及能力的研究

本文对扶桑绵粉蚧的交配行为及交配能力进行观察,以期明确其交配行为和交配能力。研究发现,发现扶桑绵粉蚧雌雄虫均能多次交配,雄虫交配能力大于雌虫。雄虫交配次数为3～10次不等,平均为6.9次,以交配6次所占的比率最大,为26.7%。雌虫的交配次数为1～4次不等,平均为2.3次,以交配2次所占的比率最大,为40.0%。扶桑绵粉蚧的交配持续时间差异较大,从1.8 min到76.5 min不等,平均每次交配时间为11.5 min,其中以在10 min以内最多,为68.8%。上述研究为了解扶桑绵粉蚧的交配行为和研究昆虫性信息素提供了科学的依据。     

马铃薯块茎蛾的交配行为

在温度为(24±2)℃、光周期为L∶D=14∶10、相对湿度为50%～70%环境条件下观察了马铃薯块茎蛾Phthorimaea operculella(Zeller)交配行为。结果表明,1～2日龄、3～4日龄成虫交配高峰期分别发生在进入暗期后的8.0～10.0h、6.5～8.0h内。两性交配率随日龄的增加显著下降。马铃薯块茎蛾雄成虫具有多次交配能力,在连续发生2次以上行为交配时会导致雄蛾有效交配率下降。雄蛾平均有效交配次数可达3.8次/头,最高达6次。增加雄性比例不会显著提高单雌产卵量,但将性比(♀:♂)由1∶1升至2∶1时即可显著降低单雌产卵量。     

绿缘扁角叶甲生活史、交配及繁殖的观察

【目的】探明绿缘扁角叶甲Platycorynus parryi Baly年生活史、交配及繁殖情况。【方法】越冬代成虫在室内自然条件下连续繁殖,及在不同温度下,详细观察记录了成虫的交配、繁殖力和寿命。【结果】绿缘扁角叶甲是络石Trachelospermum jasminoides的重要害虫,以老熟幼虫在3~5 cm深的土层中越冬,在江西南昌一年发生1代。越冬幼虫于次年4月中旬开始陆续化蛹,4月下旬成虫开始羽化。自然条件下各虫态发育历期:卵期(11.81±0.17)d,幼虫期300~330 d,蛹期(13.62±0.13)d,成虫寿命(47.99±0.65)d。成虫羽化3~4 d后开始交配,日平均交配(3.55±0.11)次,交配持续时间最短5 min,最长可达140 min,平均交配持续时间(28.11±0.89)min,日龄大的成虫交配持续时间显著短于日龄小的成虫;相邻两次交配之间的间隔时间最短3 min,最长426 min,平均交配间隔时间(74.75±3.19)min,日龄大的成虫交配间隔时间显著短于日龄小的成虫。交配后2~3 d开始产卵,平均每雌产卵量为169粒。在22、25和28℃条件下,温度对雌虫寿命具有显著影响,随着温度升高,雌虫寿命显著缩短,而雄虫寿命和每雌产卵量却差异不显著。【结论】绿缘扁角叶甲在江西南昌一年发生1代,以老熟幼虫在土中越冬,成虫可进行多次交配,成虫日龄对其交配行为有显著影响,温度对该虫的繁殖力无显著影响。     

意大利蝗交配行为观察

通过昆虫行为观测仪与室外饲养观察,分析意大利蝗Calliptamus italicus的交配行为,阐明交配经历和温度对意大利蝗交配持续时间的影响。结果发现:(1)意大利蝗的交配行为包括相遇和交配两个阶段。相遇行为包括避让、打斗和交配3种类型,其中打斗多发生在雄雄相遇、雄虫与一对正在交配成虫相遇情况。避让和交配则多发生在雌雌相遇、雌雄相遇、雌虫与一对正在交配成虫相遇情况。雄虫在交配过程中占据主动。意大利蝗的交配行为包括曲腹、爬背、抱对和交配4个过程,平均时间为11.25±1.40 min。(2)雌雄虫初次交配的持续时间(12.88±0.67 min)显著长于雌雄虫均有交配经历的时间(10.47±0.39 min)(P0.05);初次交配雌虫和有交配经历雄虫的交配持续时间(11.00±0.75 min),与初次交配雄虫和有交配经历雌虫的时间(12.12±0.67 min)无显著差异(P0.05)。(3)随温度升高意大利蝗的交配持续时间缩短,27℃时交配持续时间最长(15.93±2.25 min),且与36℃、42℃时的时间差异显著(P0.05),42℃时的交配持续时间最短,为6.01±0.43 min,与36℃时的时间(7.47±0.52 min)差异不显著(P0.05)。     

Effects of delayed mating on reproductive output of female oriental beetle Anomala orientalis (Coleoptera: Scarabaeidae)

1 Although management of the oriental beetle Anomala orientalis (Waterhouse) by mating disruption shows promise across a range of agricultural systems, relatively little is known about aspects of the reproductive biology of this species relevant to its management. We studied the effects of delayed mating on several aspects of the oviposition behaviour and biology of the oriental beetle using females mated in the laboratory at 4–13 days posteclosion. 2 Females exhibited a gradual decline in fecundity with increased age at mating that was largely a function of a decline in duration of the oviposition period, as well as lower female fertility: females mated at 11 days were less likely to lay any fertile eggs. However, egg fertility did not vary with female age at mating. 3 Because mating delay did not affect longevity, females mated at older ages experienced decreased oviposition periods; however, females laid more eggs per day with increased age at mating, which partially offset shorter oviposition periods. 4 A mating delay of ≥ 6 days relative to females mated within the first day of reaching sexual maturity resulted in an approximately 35–50% lower mean fecundity. 5 These results suggest that, for mating disruption to be a successful management tool for the oriental beetle, mating must be prevented rather than delayed. We compare the findings of the present study with the published research on delayed mating in moths and discuss the importance of these results in relation to management of the oriental beetle using female sex pheromones.     

An effect of mate fertility on the attractiveness and oviposition rates of mated Drosophila melanogaster females

Mate fertility has a strong influence on the sexual receptivity of mated Drosophila melanogaster females, but an effect of mate fertility on the attractiveness of mated females has not previously been demonstrated. We compared the declines in attractiveness over the first 10 h after mating for females mated to fertile (XY) males and those mated to sterile (XO) males, and found a significant effect of mate fertility. A large and significant decrease in attractiveness, that is the same for both XY- and XO-mated females, is evident during the first 4 h after mating. However, a further decline in attractiveness occurs between 4 and 6 h after mating for XY-mated females, but not until between 6 and 10 h after mating for females with sterile mates. Thus, XY-mated females are significantly less attractive than XO-mated females at 6–8 h post-mating, but not at any other time. A sharp increase in oviposition rates for both types of mated females is associated with the decline in attractiveness that occurs between 4 and 10 h after mating.     

Effect of male and female multiple mating on the fecundity, fertility, and longevity of diamondback moth, Plutella xylostella (L.)

Abstract:  The effect of diamondback moth (DBM), Plutella xylostella (Lep., Plutellidae) male and female multiple mating on fecundity, fertility, and longevity was studied. Males could mate for five times with virgin females during scotophase. The successful copulation rates, fecundity of female, and longevity of both females and males decreased when male mating times increased, whereas copulation duration increased. Correlation coefficient between copulation duration and male mating times was significant ( r  = 0.7358, P = 0.0001, spearman rank-order correlation). There were linear relationships between mating history of males and longevities of males and females, and regression relationships between them were significant. Mated females had similar daily reproductive pattern, which laid the most eggs on the first day after mating in spite of their mates' mating history. Virgin females laid some infertile eggs before they died. Most of the females mated once during their lifespan but 19.9% of females mated twice when one female kept with one male during scotophase. There were no significant differences in the fecundity, fertility and longevity between the single- and twice-mated females. Correlation coefficient between copulation duration and female mating times was not significant ( r  = 0.0860, P = 0.8575). Results suggested that DBM females may be monandrous. Multiple mating did not increase male or female mating fitness.     

Mating Behavior of Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) and the Effect of Female Mating Frequency on Offspring Production

The courtship behavior of Cephalonomia tarsalis, a solitary semiectoparasitoid of Oryzaephilus surinamensis, was investigated in the laboratory. Courtship behavior includes a series of stereotypic movements. Males play the most active role, executing the majority of courtship action, and females respond with relatively limited observable behaviors. Males typically keep antennae still during encounters with females prior to mounting, which may be correlated with recognition of the female's sexual status. After mounting, males display a series of movements on females, such as antennae touching female's antennae, antennae or mouth touching female's head or thorax, and walking around on female, which may serve to stimulate females towards increased receptivity. Females signal receptivity by assuming a stereotypical posture of remaining stationary, with head down, and antennae still in front of the body. The male then inserts his aedeagus and the pair copulates. After an average of 40.4 s of copulation, females signal the end of copulation by waving the antennae and moving away from the copulation site. Males continue copulating for a short time after females start moving but dismount soon thereafter. After dismounting, the two wasps move away from each other immediately, and they typically begin grooming. Neither males nor females exhibit mating preference based on mate's mating status in both choice and no-choice tests. The male is polygynous and the mated female can mate multiple times within the first 3 days after starting oviposition. However, female mating frequency does not affect the production of female progeny.     

Effects of delayed mating and male mating history on longevity and reproductive performance of the rice stem borer, Chilo suppressalis (Walker) (Lep., Pyralidae)

Abstract:  The mating potential, effects of delayed mating and male mating history on longevity and reproductive performance of female rice stem borer (RSB), Chilo suppressalis , were investigated under laboratory conditions. Given the opportunity, RSB males copulated an average of 2.7 times, while females generally mated only once. Females were more severely affected by mating delay than males in terms of female longevity and reproductive performance. With increasing age at mating, females' longevity increased, while oviposition period, fecundity and egg fertility decreased. Mean fecundity and egg fertility of females mated 1 and 7 days after emergence were 251.3% and 99.2%, and 96.2% and 75.5% respectively. Both were reduced significantly when female mating was delayed beyond 4 days after emergence. However, irrespective of the first mating age and different mating history of the males, the results indicated that both did not result in a significant difference in the quality of their contributions to female longevity and reproductive performance. The results obtained in this study are discussed in relation to the potential effect on pheromone control of RSB.     

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.     

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).     

Polyandrous females acquire indirect benefits in a nuptial feeding species

The relative force of direct and indirect selection underlying the evolution of polyandry is contentious. When females acquire direct benefits during mating, indirect benefits are often considered negligible. Although direct benefits are likely to play a prominent role in the evolution of polyandry, post‐mating selection for indirect benefits may subsequently evolve. We examined whether polyandrous females acquire indirect benefits and quantified direct and indirect effects of multiple mating on female fitness in a nuptial gift‐giving spider (Pisaura mirabilis). In this system, the food item donated by males during mating predicts direct benefits of polyandry. We compared fecundity, fertility and survival of singly mated females to that of females mated three times with the same (monogamy) or different (polyandry) males in a two‐factorial design where females were kept under high and low feeding conditions. Greater access to nutrients and sperm had surprisingly little positive effect on fitness, apart from shortening the time until oviposition. In contrast, polyandry increased female reproductive success by increasing the probability of oviposition, and egg hatching success indicating that indirect benefits arise from mating with several different mating partners rather than resources transferred by males. The evolution of polyandry in a male‐resource‐based mating system may result from exploitation of the female foraging motivation and that indirect genetic benefits are subsequently derived resulting from co‐evolutionary post‐mating processes to gain a reproductive advantage or to counter costs of mating. Importantly, indirect benefits may represent an additional explanation for the maintenance of polyandry.     

Male Mating History Influences Female Mate Choice in the Trinidadian Guppy (Poecilia reticulata)

Based on the phenotype‐linked fertility hypothesis, sexual selection should favour females that can accurately assess the recent mating history of available sexual partners and preferentially avoid mating with recently‐mated males [who may be sperm depleted (SD)] so as to minimize the risk of their eggs not being fertilized. This hypothesis has received to date only limited attention and empirical support. Therefore, in the current study, we investigated experimentally whether females of a vertebrate species, the Trinidadian guppy (Poecilia reticulata), are able to assess the recent mating history of males, and thus potentially their functional fertility, and choose to avoid mating with males that appear to have recently mated and who may be sperm limited. Individual virgin females were first given a dichotomous choice between a male that had not been recently observed to interact sexually with another female (i.e. not sperm‐depleted) and another male that had been observed to interact sexually with a female (i.e. potentially sperm‐depleted) as sexual partners. Paired males were matched for body length and coloration. Immediately following this test, the focal females were subjected to a free‐swimming mate‐choice test using the same paired stimulus males. As predicted, on average, female guppies avoided the apparently recently‐mated (and potentially sperm‐depleted) male and exhibited a significant preference for the other male not recently observed mating (and thus not likely sperm limited) during both tests. We do not yet fully understand the underlying mechanisms of this preference. Therefore, further research on the particular cues that females use to assess the recent mating history and fertility status of males is required.