六星黑点豹蠹蛾求偶行为与性信息素产生和释放的时辰节律

六星黑点豹蠹蛾Zeuzera leuconotum Butler(Lepidoptera:Cossidae)是一种重要的园林害虫。为研究利用其性信息素防控六星黑点豹蠹蛾,在光周期L∶D=14∶10、温度19—32℃、相对湿度75%—85%条件下,对雌蛾求偶行为进行了观察;采用腺体提取法和瓶内收集法分别制备了不同日龄在同一时辰、同日龄在不同时辰的雌蛾性信息素粗提物,然后测定雄蛾触角对各种性信息素提取物的触角电位反应;以雄蛾对腺体提取物的EAG值表示性信息素的产生量,对瓶内收集物的EAG值表示释放量,检测性信息素产生与释放的时辰节律。结果表明:雌蛾求偶均发生在暗期;雌蛾求偶率与日龄有关,其中2日龄雌蛾求偶率最高,平均为86.7%;不同日龄雌蛾求偶高峰期均在进入暗期4—6h期间;随着虫龄的增加,求偶高峰期前移。雌蛾羽化当晚体内即可产生性信息素,并且向体外释放,但量较少;2日龄雌蛾产生和释放的性信息素量最大;雌蛾腺体中性信息素含量从进入暗期后逐渐增加,在暗期5h含量最高,随后逐渐减少;雌蛾释放性信息素从暗期4h开始,至暗期6h释放量最大。通过林间处女雌蛾诱捕试验证明了六星黑点豹蠹蛾的求偶行为与性信息素产生和释放在时辰节律上具有一致性。     

黄褐幕枯叶蛾生殖行为研究和林间引诱试验

【目的】为探索一种高效、无污染的防治黄褐幕枯叶蛾Malacosoma neustria testacea Motschulsky(Lepidoptera:Lasiocampidae)的方法,本文对其生殖生物学特征进行了研究。【方法】本试验于2013年和2014年期间通过室外笼内人工饲养和野外调查相结合,观察黄褐幕枯叶蛾的生殖行为学特征。【结果】黄褐幕枯叶蛾羽化期40 d左右,羽化高峰在6月19日―7月03日,日羽化高峰期在17:00―19:00,雌雄平均性比为1︰(1.19±0.07),未交配雌雄成虫的平均寿命分别为(4.13±0.142)d和(4.57±0.035)d,雄蛾的寿命高于雌蛾。在凌晨0:00―3:00均能观察到雌蛾有明显的求偶行为。成虫交尾高峰在凌晨2:30左右,1日龄的成虫交尾率最高(61.67%±2.89%),随着日龄的增加成虫的交尾行为逐渐减弱。交尾持续时间最短为20 min,最长可达135 min。林间诱蛾实验中,未交配雄蛾和空白对照都没有引诱到成虫,1~6日龄未交配雌蛾均能引诱到雄虫,且1日龄未交配雌蛾诱蛾量最大,凌晨2:00―3:00是诱蛾高峰期;凌晨1:30未交配雌蛾性腺提取物的引诱量最大,1日龄未交配雌蛾性腺提取物对雄蛾的引诱效果最佳。【结论】本试验的研究结果为利用昆虫性信息素防治黄褐幕枯叶蛾奠定了基础。     

六星黑点豹蠹蛾性信息素活性成分的提取和初步鉴定

[目的]初步鉴定六星黑点豹蠹蛾Zeuzera leuconotum Butler (Lepidoptera,Cossidae)雌蛾性信息素活性成分.[方法]采用正己烷溶剂浸提法提取六星黑点豹蠹蛾性信息素腺体中的化学组分,利用毛细管气相色谱(GC)和气相色谱-质谱联用(GC-MS)技术分析性腺提取物,并运用触角电位技术(EAG)测定提取物及标准化合物的电生理活性.[结果]GC结果显示六星黑点豹蠹蛾性腺体提取物中主要存在7种成分,其中G组分在加入标准化合物反-2-顺-13-十八碳烯醇-1-乙酸酯(E2,Z13-18:Ac)后,峰高和峰面积均相应增加.GC-MS分析结果证明G组分为E2,Z13-18:A.EAG结果显示7种组分均能引起雄蛾触角电位反应,其中对E2Z13-18:Ac的反应值最大.[结论]本研究初步鉴定出E2,Z13-18:Ac是六星黑点豹蠹蛾的性信息主要组分,为使用性信息素防治六星黑点豹蠹蛾奠定了基础.     

六星黑点豹蠹蛾性信息素活性成分的提取和初步鉴定

[目的]初步鉴定六星黑点豹蠹蛾Zeuzera leuconotum Butler (Lepidoptera,Cossidae)雌蛾性信息素活性成分.[方法]采用正己烷溶剂浸提法提取六星黑点豹蠹蛾性信息素腺体中的化学组分,利用毛细管气相色谱(GC)和气相色谱-质谱联用(GC-MS)技术分析性腺提取物,并运用触角电位技术(EAG)测定提取物及标准化合物的电生理活性.[结果]GC结果显示六星黑点豹蠹蛾性腺体提取物中主要存在7种成分,其中G组分在加入标准化合物反-2-顺-13-十八碳烯醇-1-乙酸酯(E2,Z13-18:Ac)后,峰高和峰面积均相应增加.GC-MS分析结果证明G组分为E2,Z13-18:A.EAG结果显示7种组分均能引起雄蛾触角电位反应,其中对E2Z13-18:Ac的反应值最大.[结论]本研究初步鉴定出E2,Z13-18:Ac是六星黑点豹蠹蛾的性信息主要组分,为使用性信息素防治六星黑点豹蠹蛾奠定了基础.     

六星黑点豹蠹蛾性信息素活性成分的提取和初步鉴定

[目的]初步鉴定六星黑点豹蠹蛾Zeuzera leuconotum Butler (Lepidoptera,Cossidae)雌蛾性信息素活性成分.[方法]采用正己烷溶剂浸提法提取六星黑点豹蠹蛾性信息素腺体中的化学组分,利用毛细管气相色谱(GC)和气相色谱-质谱联用(GC-MS)技术分析性腺提取物,并运用触角电位技术(EAG)测定提取物及标准化合物的电生理活性.[结果]GC结果显示六星黑点豹蠹蛾性腺体提取物中主要存在7种成分,其中G组分在加入标准化合物反-2-顺-13-十八碳烯醇-1-乙酸酯(E2,Z13-18:Ac)后,峰高和峰面积均相应增加.GC-MS分析结果证明G组分为E2,Z13-18:A.EAG结果显示7种组分均能引起雄蛾触角电位反应,其中对E2Z13-18:Ac的反应值最大.[结论]本研究初步鉴定出E2,Z13-18:Ac是六星黑点豹蠹蛾的性信息主要组分,为使用性信息素防治六星黑点豹蠹蛾奠定了基础.     

褛裳夜蛾的交配行为及雄蛾对性腺提取物的反应节律

详细观察了褛裳夜蛾成虫的交配行为,利用风洞、触角电位技术研究了雄蛾对性腺提取物的反应节律,通过林间诱蛾试验进行了验证,旨在为褛裳夜蛾性信息素的精确提取及性信息素组份分离、鉴定提供依据。研究结果表明:成虫的求偶、交配行为均发生在暗期,有一定的节律性:雌蛾在羽化3d以后开始求偶,1周左右表现最为强烈,3-4日龄雌蛾在暗期4-6h开始求偶,最大求偶率在暗期6-8h;5-9日龄在进入暗期就开始求偶,最大求偶率出现在暗期4-6h。风洞试验表明,3-7日龄的雄蛾对性腺提取物均有明显的性行为反应,5日龄雄蛾在暗期4-6h对性腺提取物的反应最为强烈。3-6日龄的成虫在暗期4-6h开始交配,而7-8日龄的成虫于暗期2-4h开始交配,6日龄的成虫交配率最高,交配高峰在暗期4-8h。雄蛾对性腺提取物的触角电位反应也有一定的节律性:雄蛾对4日龄雌蛾性腺提取物开始有电生理反应,对6-7日龄暗期5h性腺提取物反应最为强烈。林间诱蛾试验测定了性腺提取物的引诱活性,7日龄雌蛾性腺提取物林间诱蛾量最高,引诱高峰在暗期4-6h,该结果也验证了褛裳夜蛾雄蛾对性腺提取物的反应节律。     

二化螟雄蛾交配行为与精巢大小的关系

【目的】为了明确二化螟Chilo suppressalis雄蛾交配行为与精巢大小的关系,阐明信息素群集诱杀防治二化螟的有效性。【方法】本研究通过测定和比较不同日龄、交配状态以及性信息素诱捕的二化螟雄蛾精巢体积,建立精巢体积与雄蛾发育及交配状态的相关性。【结果】雄蛾日龄显著影响二化螟的交配,刚羽化(0日龄)雄蛾的交配率较低,1日龄雄蛾的交配率最高,之后随着日龄增加交配率逐渐降低。精巢体积与二化螟雄蛾日龄之间存在显著的负相关性。同一日龄交配的二化螟雄蛾的精巢体积显著大于未交配雄蛾;性诱捕器诱捕雄蛾的精巢体积显著大于未被性诱捕器诱捕雄蛾,与已交配雄蛾的精巢体积相似。交配之后,精巢的发育过程和未交配雄蛾相似。田间性信息素引诱二化螟雄蛾精巢体积小于0-1日龄未交配雄蛾,大于2-6日龄未交配雄蛾。【结论】本研究结果表明,二化螟雄蛾对雌蛾性信息素的反应与其精巢大小存在正相关性;性信息素引诱的二化螟雄蛾具有更强的性信息素反应能力,同时性信息素引诱的大部分雄蛾为未交配状态;交配过程并不影响二化螟雄蛾精巢体积,也不影响精巢发育。二化螟交配能力与精巢大小的关系在理论上解释了性信息素群集诱杀二化螟的防控有效性,并为其他蛾类昆虫的交配研究提供依据。     

榆木蠹蛾生殖行为及性信息素产生与释放节律

通过室内饲养与野外观察榆木蠹蛾Holcocerus vicarius (Walker)成虫的羽化、交尾、产卵行为,触角电位反应测定处女雌蛾性信息素产生与释放节律,旨在为榆木蠹蛾性信息素的鉴定和合成奠定基础。结果表明：榆木蠹蛾羽化行为全天可见,主要集中在15:00－19:00。成虫羽化当日即可交尾,21:30－0:30进行婚飞和交尾,交尾高峰出现在晚23:00左右,光期未见交尾。随着日龄的增加,召唤时间前移并且延长,2～3日龄处女雌蛾召唤时间早于1日龄雌蛾,交尾时间较短;雌蛾在羽化1 d后达到性成熟,2日龄雌蛾交尾百分率最高,达41.8%。雌蛾将产卵器伸出寻找缝隙处产卵,分多处产卵,雌虫最高产卵量达720粒,最低产卵量为105粒,卵期为12～22 d不等,孵化率为72%～88%。羽化当晚的雌蛾体内性信息素含量较低,第2天最高,以后逐日下降;2日龄榆木蠹蛾处女雌蛾性信息素的产生量从晚17:00起逐渐增加, 21:30－22:00时最高, 22:00后逐渐减小。雄蛾触角电位反应在22:30最强。21:30－23:00是雌蛾产生和释放性信息素的高峰期。榆木蠹蛾的羽化、交尾存在一定的时辰节律,通过处女雌蛾的野外诱集试验证实了性信息素释放与交配行为在时辰节律上的一致性。     

笋秀夜蛾的求偶及交配行为

笋秀夜蛾(Apamea apameoides)是我国南方地区最为重要的笋期害虫,了解其求偶和交配行为是性信息素分离鉴定和应用的关键之一。在室内条件下,对笋秀夜蛾的性比、寿命和求偶、交配行为进行了研究。结果表明:笋秀夜蛾雌雄性比为1∶0.76;雌蛾和雄蛾的平均寿命因交配缩短;笋秀夜蛾的求偶和交配行为仅发生在暗期,日龄对其求偶和交配行为影响显著。雌蛾羽化当天便可求偶,第2日雌蛾求偶率达最高,求偶的起始时间随着日龄的增加逐渐提前。成虫羽化当日便可交配,第3日达到交配高峰;随日龄的增加,开始交配的时间逐渐提前,日龄对成虫交配高峰出现的时间影响不显著。     

沙柳木蠹蛾性行为及其性信息素滴度的动态节律

沙柳木蠹蛾Holcocerus arenicola是为害沙柳Salix psammophila的主要钻蛀性害虫之一。在进入暗期后的6 h内,对其求偶行为和交配行为进行观察和记录,调查该虫求偶和交配的活动规律。通过触角电位技术（EAG）和毛细管气相色谱（GC）对性腺体内信息素的滴度进行了分析,以揭示性信息素产生的昼夜节律和雌虫日龄对性信息素合成的影响。结果表明：该虫在暗期0.5~1 h内即开始有求偶行为,最大求偶高峰出现在羽化后的第2晚。交配行为主要发生在暗期的1~2 h内。在各日龄的成虫中,1日龄成虫的交配百分率最高。交配平均时间为24.16±2.64 min,随着日龄的增加,交配时间前移。在实验中,未观察到5~6日龄成虫的交配行为。沙柳木蠹蛾性信息素的体内合成早于求偶行为1~2 h,并在暗期的前2 h内达到峰值。性信息素的滴度随着雌虫日龄的增减而减少,最高值为当日羽化雌虫的腺体提取物。林间诱蛾实验中,处女雌蛾和性腺体提取物对雄蛾均有较好的诱捕效果。本研究表明,在沙柳木蠹蛾的性信息素滴度和性活动之间具有同步关系,同时为进一步利用长距离性信息素防治该虫提供了参考。     

Male sexual behavior does not require elevated testosterone in a lizard (Coleonyx elegans, Eublepharidae)

Male sexual behavior depends on gonadal androgens in species of all major vertebrate lineages, including reptiles. However, male sexual behavior includes distinct appetitive and consummatory phases, typically denoted as courtship and mounting, with potentially different hormonal control. Different proximate controls of courtship versus mounting could enable disconnected evolutionary losses and gains of various aspects of male sexual behavior. Male courtship display, which is activated by testosterone (T) in many species, is an ancestral trait in the lizard family Eublepharidae. However, Coleonyx elegans (Yucatan Banded Gecko) lost the courtship display, while retaining a highly simplified male sexual behavior that involves only mounting for copulation. We performed surgical manipulations (castration with and without T replacement in adult males; implantation of adult females with exogenous T) to investigate hormonal mechanisms involved in this evolutionary novelty. Our results indicate that the expression of simplified sexual behavior in C. elegans does not require elevated circulating levels of T, a finding that is previously unreported in lizards. In females, however, exogenous T induced male-like mounting. Thus, the mounting phase of sexual behavior is not activated by T in the traditional sense of this term but probably requires post-natal, maturational organization (if not periodic reorganization) by androgens. We conclude that the simplification of male sexual behavior and its independence from elevated levels of circulating androgens in C. elegans evolved via 1) evolutionary loss of the androgen-activated courtship display and 2) retention of the mounting phase, which has a longer “functional memory” for the effects of androgenic steroids.     

Individual and seasonal variation in fecal testosterone and cortisol levels of wild male tufted capuchin monkeys, Cebus apella nigritus

This study tested the "challenge hypothesis" and rank-based predictions for temporal steroid production in male tufted capuchin monkeys, Cebus apella. Fecal samples (n = 209) collected from six wild males were analyzed for testosterone and cortisol concentration by enzyme immunoassay. The temporal pattern in male steroid production was compared to female sexual activity and rates of male aggression. The top-ranking adult male did not differ from other adult males in testosterone or cortisol concentration. Mean adult testosterone was significantly higher than mean subadult testosterone throughout the year. There was a clear elevation of testosterone and cortisol in both adult and subadult males during the peak of adult female sexual activity after the birth season. In fact, the magnitude of increase in testosterone was higher than predicted for a species with low male-male aggression. However, there was no difference between nonbreeding baseline testosterone levels during the birth season, and the "breeding" baseline of testosterone in males found during asynchronous female sexual activity. Of all behavioral indices examined, the distribution of female-maintained consortships was the best predictor of mean adult male testosterone concentrations. Although in many species, elevated testosterone coincides with increased male-male aggression, in the present study, the sustained high-magnitude increase in steroids during the peak of adult female sexual activity was associated with a relatively low rate of male-male intragroup aggression.     

Mating and Sexual Communication by Steinernema carpocapsae (Nemata: Steinernematidae)

Entomopathogenic nematodes are lethal insect parasites that reproduce exclusively inside their hosts in nature. Infection decisions made by the free-living infective-stage juveniles have an impact on reproductive success, but it is likely that mating decisions are made by adults while inside their host. We investigated sexual communication between male and female adult stages of Steinernema carpocapsae (Rhabditida: Steinernematidae) to assess whether mating is chemically mediated during the adult stage or results from incidental encounters between adults inside the insect host. To assess chemical communication, we measured the behavioral response of adult male S. carpocapsae to several different potential sources of chemical information. Male S. carpocapsae responded to virgin females only and were not influenced by mated conspecific females, conspecific males, or heterospecific females. These results show that species-specific communication takes place between adult entomopathogenic nematodes within the host cadaver just prior to mating.     

年龄和性别因素对奇台沙蜥食性的影响

采用胃容物分析法研究年龄和性别因素对奇台沙蜥(Phrynocephalus grumgrzimailoi)食性的影响.共解剖220号浸制标本,取出整胃分离胃容物,鉴别胃容物中的食物种类,统计各种食物组分的数量频率、重量比例、出现频率和相对重要性指数(index of relative importance,IRI).结...     

Mechanisms of sexual selection: sexual swellings and estrogen concentrations as fertility indicators and cues for male consort decisions in wild baboons

Male mate-guarding episodes ('consortships'), are taxonomically widespread, yet costly to individual males. Consequently, males should bias consortships toward females with whom the probability of conception is high. We combined data on consortships with visual scoring of sexual swellings and assays of fecal estrogen concentrations (fE) in a wild population of baboons (Papio cynocephalus) to test the hypotheses that sexual swellings are reliable indicators of (1) within-cycle timing of ovulation, (2) differences in conception probability among females that differ in maturational stage, and (3) conceptive versus non-conceptive cycles of parous females. We also evaluated whether adult males might rely on swellings or other estrogen-dependent signals (e.g., fE) for mate-guarding decisions. We found that sexual swellings reflected conception probability within and among cycles. Adult males limited their consortships to the turgescent phase of cycles, and consorted more with adult females than with newly cycling adolescents. The highest ranking (alpha) males discriminated more than did males of other ranks; they (1) limited their consortships to the 5-day peri-ovulatory period, (2) consorted more with adult than with adolescent females, and (3) consorted more with adult females on conceptive cycles than on non-conceptive cycles, all to a greater extent than did males of other ranks. Male mate choice based on sexual swellings and other estrogenic cues of fertility may result in sexual selection on these female traits and enhance dominance-based reproductive skew in males. Alpha males are the least constrained in their mating behavior and can best take advantage of these cues to mate selectively.     

中华卵索线虫的性别分化分子机理研究进展

中华卵索线虫Ovomermis sinensis Chen et al.是一种宝贵的昆虫天敌资源,具有特殊的寄生期营养竞争压力决定其雌雄性别分化机制。本文重点概述了近年中华卵索线虫性别决定与分化、寄生期生理生化以及分子系统学研究等方面的进展,并对中华卵索线虫今后的研究方向提出了建议。     

三唑磷防治咖啡木蠹蛾的初步研究

咖啡木蠢蛾在福建省1年发生2代,幼虫的孵化高峰期分别发生在6月与10月,掌握其幼虫孵化高峰期适时喷施20％三唑磷乳油1500倍稀释液,结果表明,对药前10d内孵化已蛀枝干的幼虫杀虫率为90oA～100％,对药后10d内已蛀枝干的幼虫杀虫率为85％～100％,2次施药就能有效防治咖啡木蠢蛾为害。由于此法简便,经济,易行,故建议在生产上可以推广应用。     

Population genetics of complex life-cycle parasites: an illustration with trematodes

Accurate inferences on population genetics data require a sound underlying theoretical null model. Organisms alternating sexual and asexual reproduction during their life-cycle have been largely neglected in theoretical population genetic models, thus limiting the biological interpretation of population genetics parameters measured in natural populations. In this article, we derive the expectations of those parameters for the life-cycle of monoecious trematodes, a group comprising several important human and livestock parasites that obligatorily alternate sexual and asexual reproduction during their life-cycle. We model how migration rates between hosts, sexual and asexual mutation rates, adult selfing rate and the variance in reproductive success of parasites during the clonal phase affect the amount of neutral genetic diversity of the parasite (effective population size) and its apportionment within and between definitive hosts (using F-statistics). We demonstrate, in particular, that variance in reproductive success of clones, a parameter that has been completely overlooked in previous population genetics models, is very important in shaping the distribution of the genetic variability both within and among definitive hosts. Within definitive hosts, the parameter F(IS) (a measure of the deviation from random mating) is decreased by high variance in clonal reproductive success of larvae but increased by high adult self-fertilisation rates. Both clonal multiplication and selfing have similar effects on between-host genetic differentiation (F(ST)). Migration occurring before and after asexual reproduction can have different effects on the patterns of F(IS), depending on values of the other parameters such as the mutation rate. While the model applies to any hermaphroditic organism alternating sexual and clonal reproduction (e.g. many plants), the results are specifically discussed in the light of the limited population genetic data on monoecious trematodes available to date and their previous interpretation. We hope that our model will encourage more empirical population genetics studies on monoecious trematodes and other organisms with similar life-cycles.     

Differential inhibition of Helicoverpa armigera gut proteinases by proteinase inhibitors of pigeonpea (Cajanus cajan) and its wild relatives

The seeds of 36 pigeonpea [Cajanus cajan (L) Millsp.] cultivars, resistant and susceptible to pests and pathogens and 17 of its wild relatives were analysed for inhibitors of trypsin, chymotrypsin, and insect gut proteinases to identify potential inhibitors of insect (Helicoverpa armigera) gut enzymes. Proteinase inhibitors (PIs) of pigeonpea cultivars showed total inhibition of trypsin and chymotrypsin, and moderate inhibition potential towards H. armigera proteinases (HGP). PIs of wild relatives exhibited stronger inhibition of HGP, which was up to 87% by Rhynchosia PIs. Electrophoretic detection of HGPI proteins and inhibition of HGP isoforms by few pigeonpea wild relative PIs supported our enzyme inhibitor assay results. Present results indicate that PIs exhibit wide range of genetic diversity in the wild relatives of pigeonpea whereas pigeonpea cultivars (resistant as well as susceptible to pests and pathogens) are homogeneous. The potent HGPIs identified in this study need further exploration for their use in strengthening pigeonpea defence against H. armigera.     

Climate change and sexual size dimorphism in an Arctic spider

Climate change is advancing the onset of the growing season and this is happening at a particularly fast rate in the High Arctic. However, in most species the relative fitness implications for males and females remain elusive. Here, we present data on 10 successive cohorts of the wolf spider Pardosa glacialis from Zackenberg in High-Arctic, northeast Greenland. We found marked inter-annual variation in adult body size (carapace width) and this variation was greater in females than in males. Earlier snowmelt during both years of its biennial maturation resulted in larger adult body sizes and a skew towards positive sexual size dimorphism (females bigger than males). These results illustrate the pervasive influence of climate on key life-history traits and indicate that male and female responses to climate should be investigated separately whenever possible.