暗褐蝈螽与优雅蝈螽精子超微结构的比较研究(直翅目,螽斯科)

研究了暗褐蝈螽Gampsocleis sedakovii(Fischer von Waldheim)和优雅蝈螽G.gratiosa Brunner von Wattenwyl精子的超微结构。这两种蝈螽精子头部的顶体复合体由顶体外层、顶体本体和顶体组成,顶体复合体位于细胞核前端,并包裹部分细胞核;颈部具5纵层细胞器;尾部鞭毛轴丝为典型的9+9+2型,线粒体衍生体部分晶状化。暗褐蝈螽精子较短,顶体复合体夹角较大,精子鞭毛横切面直径稍大;优雅蝈螽精子稍长,顶体复合体夹角较小,精子鞭毛横切面直径较小,两种精子超微结构差异不显著,其生殖隔离机制有待进一步研究。     

优雅蝈螽雌虫性选择

优雅蝈螽雌虫在交配过程中接受雄虫分泌的精包,并且在交配后一段时间内把精包吃掉。精包对雌虫的生殖是必需的,体重大的雄性分泌的精包较大。把2只鸣叫的且体重不同的雄虫放在一起,雌虫会选择体重大的个体交配。     

迷卡斗蟋和短翅鸣螽的行为谱及交配行为

研究了迷卡斗蟋和短翅鸣螽的行为模式及迷卡斗蟋鸣叫的时间分布。结果表明迷卡斗蟋雄虫单独存在时 ,在一昼夜内其鸣叫的持续时间为 668.38± 1 0 9.86分钟 ( 5 ) ,引入雌虫后鸣叫累计时间减少为 1 7.3± 6.7分钟 ( 5 ) ,并产生音调低沉的求偶声。在昼夜鸣叫活动型式中 ,雄虫单独存在时的鸣叫活动集中于夜间 ;引入雌虫后 ,占区鸣叫、求偶鸣唱和交配行为多集中于白天。根据上述结果提出了机会 -风险平衡假说来解释此现象 ,即白天交配有被捕食的危险 ,雄蟋短期内重复交配以保证精液进入雌蟋体内 ,从而保证了交配的成功 ,补偿了雄蟋所冒风险。短翅鸣螽雄性产生较大的精包 ,当雌体取食精包时 ,精液进入雌体内以保证交配成功。     

优雅蝈螽与暗褐蝈螽精子束的显微观察

本文应用微分干涉相衬法对优雅蝈螽Ｇampsocleis gratiosa Brunner von Wattenwyl和暗褐蝈螽G. sedakovii （Fischer von Waldheim） 雄性精巢管基部、输精管、贮精囊和精包,及雌性受精囊中精子束的形态变化进行了观察,对探讨螽斯近缘种的生殖隔离机制和生殖生物学具有重要意义.结果表明：这两种蝈螽的精子束通过精包转移到雌性受精囊后,精子束的形态发生了显著变化.精巢管基部的精子为游离的单个精子;输精管、贮精囊和精包中精子成束排列形成较分散的精子束,精子束头部包裹有粘液帽;雌性受精囊中的精子束的精子呈羽状排列,精子的头部汇集在中央轴上.两种蝈螽精子束形态差异不显著.     

交配状态对雄性短翅鸣螽(Gampsocleis gratiosa)交配投资的影响

雄性短翅鸣螽在交配过程中具有较大的交配投资, 包括营养投资(精包)和遗传投资(精子)两部分. 考查在交配过程中雌雄交配状态的4种组合处理对雄性释放出的精包与其组分以及精子数量的影响发现: 精包和精护鲜重与雄性体重成正相关关系, 而与雌性体重不相关, 这说明雄性营养投资强度取决于雄性质量而非雌性质量, 该结果支持父方投资假说. 精包及其精护、精荚鲜重在4种交配状态组合条件下没有差异, 而精子数目在雄性第二次交配过程中比第一次显著降低; 雄性在与已交配雌虫配对时, 没有显著提高繁殖投资, 该结果不支持精子竞争假说.     

瓢虫性选择行为及进化机制研究

昆虫性选择行为一直是行为生物学家和进化生物学家所关注的热点。早期对瓢虫性选择行为研究主要集中在非随机性交配模式,随着研究的深入,近些年对瓢虫性选择行为研究取得了许多新成果,包括多次交配的行为机制、性选择的识别机制、精子传送及竞争等。为全面地了解瓢虫性选择行为研究现状,本文总结了瓢虫非随机性交配模式,综述了近十余年对瓢虫性行为及进化的研究成果,同时对瓢虫性选择行为未来的研究方向进行了展望。     

北方两种常见蝈螽鸣声与发声器的比较研究

研究了北方常见的优雅蝈螽Gampsocleis gratiosa和暗褐蝈螽Campsocleis sedakovii雄性鸣声特征和发声器结构.优雅蝈螽鸣声规则,脉冲组序列由2种类型的脉冲组组成,第1种类型的脉冲组持续时间约0.09 s,脉冲持续和间隔时问约0.01 5;第2类型的脉冲组持续时间约0,04 s,脉冲持续和间隔时间均约0.003 s;鸣声的主能峰频率约7 kHz.暗褐蝈螽雄性鸣声包含短促的开翅鸣声和由2种类型的脉冲组组成的脉冲组序列构成的闭翅鸣声,第1种脉冲组持续时间约0.012 s,间隔时间约0.002 s;第2种脉冲组持续时间约0.013 s,间隔时间极短;鸣声主能峰频率约9.1kHz.2种蝈螽镜膜的形状、发声锉的形状和长度、发声齿的形状具显著差异.     

大蜡螟的性选择行为

【目的】针对大蜡螟Galleria mellonella L.的性选择行为进行系统观察分析,为大蜡螟性信息素全组分的结构鉴定及利用信息素行为调控技术防控该虫提供依据。【方法】分别对不同体重、不同日龄和不同交配经历的大蜡螟成虫进行标记,在红光灯下观察并记录大蜡螟雌雄虫的性选择行为。【结果】在（26±0.5）℃、相对湿度60%、全黑暗条件下,无论雌虫还是雄虫,均倾向于选择与之体重相接近的异性个体进行交配。雌雄成虫均偏向于选择3日龄的异性个体进行交配;雌虫对不同日龄雄虫的选择率大小顺序为3日龄> 5日龄> 1日龄,而雄虫对不同日龄雌虫的选择率大小顺序为3日龄>1日龄> 5日龄。交配经历影响大蜡螟的性选择行为,雌虫优先选择已交配的雄虫进行交配,选择率为74.6%;雄虫也优先选择已交配的雌虫进行交配,选择率为79.4%。【结论】雌雄虫体重、日龄和交配经历能不同程度的影响大蜡螟的性选择行为,这为进一步研究雌雄交配信号奠定基础。     

乌苏里蝈螽和优雅蝈螽雄性鸣声结构的比较研究

应用计算机技术分析了内蒙古草原乌苏里蝈螽Gampsocleis ussuriensis和优雅蝈螽Gampsocleis gratiosa2种螽斯雄性的鸣声结构。乌苏里蝈螽鸣声较复杂,一次鸣叫持续时间6~27s(平均12.5s),每个脉冲组由两类脉冲组组分构成,第1类脉冲组组分为振幅较大的脉冲组,脉冲组持续时间0.0065s,由6~8个脉冲串组成,每个脉冲串持续时间为0.00047s,间隔时间为0.00027s,每个脉冲串含5~10个单脉冲,脉冲串持续时间、间隔时间较短;第2类脉冲组组分为振幅较小的脉冲组,脉冲组持续时间0.0191s,约含有15个左右脉冲串,持续时间为0.00041s,间隔时间约为0.00127s,每个脉冲串含有3~5个单脉冲,脉冲串持续时间、间隔时间也较短,主能峰频率为7.98kHz。优雅蝈螽鸣声则较规则,一次鸣叫持续时间4~232s(平均41.7s)。每个脉冲组也由两类脉冲组组分构成,第1类脉冲组组分振幅较大且逐步增强,脉冲组持续时间0.119s,由10个振幅较大的脉冲串组成,每个脉冲串持续时间为0.00576s,间隔时间为0.005s,每个脉冲串含18~25个单脉冲;第2类脉冲组组分为振幅较小的脉冲组,脉冲组持续时间0.07s,约含有25个左右脉冲串,脉冲串振幅较小,含有6~9个单脉冲,主能峰频率为6.87kHz,次能峰频率为3.25kHz。结果表明乌苏里蝈螽与优雅蝈螽雄性鸣声既有相似的共同特征,同时存在较显著差异。     

北方硕螽行为模式的研究

本文采取饲养观察与相机捕捉相结合的方法对北方硕螽Deracantha onos Pallas的行为模式,如若虫行为、常见行为、鸣声行为和交配行为模式进行了观察描记。并应用分析软件对数据进行了处理。结果表明:若虫不鸣叫,午间取食;其蜕皮与温度和食性有关。成虫在各种环境条件下均出现清理触角、触角摆动、行进及取食等行为;但在营养不良空间狭小情况下,还会出现同类相食。对性成熟雄性个体的鸣声分别在独雄、双雄和一雌一雄3种情况下,以24 h为周期进行观察。独雄鸣叫时间最长,一昼夜鸣叫时间为(492.84±82.52)min,双雄时鸣叫时间最短,为(239.85±40.55)min,夜间鸣叫时间相对减少。食性和温度也对鸣叫时间有影响。鸣声是螽斯种内重要的通讯方式,在交配也会起到作用。交配时雌虫爬到雄虫的背部,雄虫尾部翘,雌虫尾部下弯,两性生殖孔相接,至雌虫生殖孔外挂精包为止。     

Effects of mating status on copulation investment by male bushcricket Gampsocleis gratiosa (Tettigoniidae, Orthoptera)

Male’s copulation investment, including spermatophore and sperm investment were very high in the Chinese bushcricket Gampsocleis gratiosa. The effects of mating status of both males and females on male’s copulation investment were examined in this study. The fresh weight of sper-matophylax increased positively with the weight of males’ body. This indicated that the nutritional in-vestment during copulation depended on male’s quality. Spermatophore investment showed insig-nificant differences in every copula...~     

Effects of mating status on copulation investment by male bushcricket Gampsocleis gratiosa (Tettigoniidae, Orthoptera)

Male’s copulation investment, including spermatophore and sperm investment were very high in the Chinese bushcricket Gampsocleis gratiosa. The effects of mating status of both males and females on male’s copulation investment were examined in this study. The fresh weight of spermatophylax increased positively with the weight of males’ body. This indicated that the nutritional investment during copulation depended on male’s quality. Spermatophore investment showed insignificant differences in every copulation protocols. This finding supported the paternal investment hypothesis, that is, males contributed to their offspring with little attention to their partners. Sperm releasing per ejaculation varied significantly among the trials. Males decreased 54.19% sperm in second mating than in its first mating, demonsrated that males regarded the first mating highly, and were more prudent in subsequent mating. These males’ strategies may contribute to the viability of the offspring.     

Effects of mating status on copulation investment by male bushcricket Gampsocleis gratiosa (Tettigoniidae, Orthoptera)

In many insect species, male will donate prey, se-cretion, and spermatophore as “nuptial gift” or “court- ship feeding” to females prior to, after or during the copulation[1,2]. The nuptial gifts represented great re-productive cost. In bushcrickets, …     

Artificial selection on sexual aggression: Correlated traits and possible trade-offs

Forced copulation is an extreme form of sexual aggression that can affect the evolution of sex-specific anatomy, morphology, and behavior. To characterize mechanistic and evolutionary aspects of forced copulation, we artificially selected male fruit flies based on their ability to succeed in the naturally prevalent behavior of forced matings with newly eclosed (teneral) females. The low and high forced copulation lineages showed rapid divergence, with the high lineages ultimately showing twice the rates of forced copulation as the low lineages. While males from the high lineages spent more time aggressively pursuing and mounting teneral females, their behavior toward non-teneral and heterospecific females was similar to that of males from the low lineages. Males from the low and high lineages also showed similar levels of male-male aggression. This suggests little or no genetic correlations between sexual aggression and non-aggressive pursuit of females, and between male aggression toward females and males. Surprisingly however, males from the high lineages had twice as high mating success than males from the low lineages when allowed to compete for consensual mating with mature females. In further experiments, we found no evidence for trade-offs associated with high forced mating rates: males from the high lineages did not have lower longevity than males from the low lineages when housed with females, and four generations of relaxed selection did not lead to convergence in forced mating rates. Our data indicate complex interactions among forced copulation success and consensual mating behavior, which we hope to clarify in future genomic work.     

昆虫性选择行为研究进展

本文综述了昆虫的各种性选择行为,包括与个体大小有关的性选择行为、与鸣声有关的性选择行为、与“婚礼食物”有关的性选择行为以及精子竞争等。     

Mating behaviors of the proboscis monkey (Nasalis larvatus)

The mating behaviors of the proboscis monkey were observed in a riverine forest along a tributary of the Kinabatangan River, Sabah, Malaysia, for a period of 30 months. Solicitation for copulation was initiated frequently by males and occasionally by females. Most copulations involved only one mount; however, some multiple-mount copulations were observed and a maximum of six mounts per copulation were recorded. The mean duration of mounts was about 27 sec. Nonsexual mounts (female-female, female-juvenile/infant, juvenile-juvenile, and juvenile-infant) were also observed. Female-female mounts occurred shortly after failed solicitations toward males were observed. Harassment by juveniles and/or infants was observed during copulation; however, these harassments apparently did not interfere with copulation. Sexual swelling was evident in 77.4% of copulating females, with copulating subadult females showing the most distinct swelling.     

The mismeasurement of sexual selection

Sexual selection can explain major micro‐ and macro‐evolutionary patterns. Much of current theory predicts that the strength of sexual selection (i) is driven by the relative abundance of males and females prepared to mate (i.e. the operational sex ratio, OSR) and (ii) can be generally estimated by calculating intra‐sexual variation in mating success (e.g. the opportunity for sexual selection, I_s). Here, we demonstrate the problematic nature of these predictions. The OSR and I_s only accurately predict sexual selection under a limited set of circumstances, and more specifically, only when mate monopolization is extremely strong. If mate monopolization is not strong, using OSR or I_s as proxies or measures of sexual selection is expected to produce spurious results that lead to the false conclusion that sexual selection is strong when it is actually weak. These findings call into question the validity of empirical conclusions based on these measures of sexual selection.     

Population variation in sexual selection and its effect on size allometry in two dung fly species with contrasting sexual size dimorphism

Body size is one of the most important quantitative traits under evolutionary scrutiny. Sexual size dimorphism (SSD) in a given species is expected to result if opposing selection forces equilibrate differently in both sexes. We document variation in the intensity of sexual and fecundity selection, male and female body size, and thus SSD among 31 and 27 populations of the two dung fly species, Scathophaga stercoraria and Sepsis cynipsea, across Switzerland. Whereas in S. cynipsea females are larger, the SSD is reversed in S. stercoraria. We comprehensively evaluated Fairbairn and Preziosi's (1994) general, three-tiered scenario, hypothesizing that sexual selection for large male size is the major driving force of SSD allometry within these two species. Sexual selection intensity on male size in the yellow dung fly, S. stercoraria, was overall positive, greater, and more variable among populations than fecundity selection on females. Also, sexual selection intensity in a given population correlated positively with mean male body size of that population for both the field-caught fathers and their laboratory-reared sons, indicating a response to selection. In S. cvnipsea, sexual selection intensity on males was lower overall and significantly positive, about equal in magnitude, but more variable than fecundity selection on females. However, there was no correlation between the intensity of sexual selection and mean male body size among populations. In both species, the laboratory-reared offspring indicate genetic differentiation among populations in body size. Despite fulfillment of all key prerequisites, at least in S. stercoraria, we did not find hypoallometry for SSD (Rensch's rule, i.e., greater evolutionary divergence in male size than female size) for the field-caught parents or the laboratory-reared offspring: Female size was isometric to male size in both species. We conclude that S. cynipsea does not fit some major requirements of Fairbairn and Preziosi's (1994) scenario, whereas for S. stercoraria we found partial support for it. Failure to support Rensch's rule within the latter species may be due to phylogenetic or other constraints, power limitations, erroneous estimates of sexual selection, insufficient genetic isolation of populations, or sex differences in viability selection against large size.