旅游干扰的水质模拟对繁殖前期中国大鲵夜间活动节律的影响

动物的日活动节律是它们对各种环境条件昼夜变化的综合适应。研究旅游干扰对繁殖前期中国大鲵(Andrias davidianus)的夜间活动节律影响,有助于探明旅游干扰是否以及如何影响大鲵繁殖行为的机理。前期研究发现旅游干扰程度与水中溶解氧(Dissolved Oxygen,DO)含量显著负相关。在大鲵繁殖前期,通过控制大鲵生态繁育池水中的进水量(主要影响DO含量)来模拟重度与轻度旅游干扰下大鲵水环境,通过监测大鲵夜间出洞与进洞时间、水温(Water Temperature,WT)、DO和大肠菌群的动态变化,比较不同旅游干扰强度下大鲵夜间活动节律的差异,以明确旅游干扰导致的水质变化对大鲵夜间活动节律的影响。结果表明,雌/雄鲵出洞时间在模拟重度旅游干扰水质下显著晚于轻度水质中,雌鲵分别为19:10±0:22与18:53±0:24,雄鲵分别在18:29±0:20与18:13±0:18。重度干扰导致水质变化分别推迟了雌/雄大鲵出洞时间约17 min与16 min。但是,雌雄大鲵进洞时间在模拟重度与轻度旅游干扰水质下,差异不显著,雌鲵分别为24:10±0:13与24:18±0:17,雄鲵分别为6:44±0:23与6:40±0:29。此外,该研究还发现,雌/雄鲵出洞时间与三种因子(WT、DO与大肠菌群)显著相关,然而,雌/雄鲵进洞时间与以上3因子不相关,可能主要由其生物钟决定。重度旅游干扰导致的水质变化对大鲵繁殖前期活动节律影响小,仅对出洞时间有一定影响。     

中国大鲵的活动节律及繁殖行为描记

采用定时定点观察法,对仿生态条件下养殖的中国大鲵(Andrias davidianus)活动节律及繁殖行为进行了观察。结果表明,大鲵活动具有明显的昼夜节律变化,白天隐藏在洞穴中不活动,每天20:30时部分大鲵开始出洞活动,21:00时至次日凌晨1:00时为活动高峰期,1:00时后部分大鲵开始陆续回到洞穴,3:00时后又全部隐藏在洞穴中;大鲵的夜间活动随季节的变化而发生周期性变化,8～9月出洞活动的大鲵数量达到一年之中的最大值。大鲵尤其是雄鲵在繁殖季节表现出明显多样的繁殖行为:①推沙行为;②求偶行为,包括聚集、露头、巡视、追随、尾阴探究、亲吻、邀请和爬跨8种行为型;③冲凉行为;④护卵行为;⑤婚配行为。     

水菖蒲活性物质β-辛醚对四纹豆象行为、死亡率和繁殖的影响

在室内条件下研究了水菖蒲Acorus calamus活性物质β-细辛醚对四纹豆象Callosobruchus maculates成虫行为、产卵和繁殖的影响。结果表明：经过β-细辛醚接触处理后的四纹豆象成虫行为主要表现为兴奋→失去平衡→击倒→死亡,接触药剂64 h后,试虫成虫全部死亡。β-细辛醚处理可显著的降低四纹豆象成虫的交配次数,随着处理时间的延长,成虫的交配次数减少,且处理雄虫比处理雌虫对交配竞争能力的影响更大。处理雌虫与未处理雄虫配对后以及处理雄虫与未处理雌虫配对后,雌虫的产卵数均极显著低于对照,且随着处理时间的延长,雌虫的产卵数显著减少,但两种配对处理之间雌虫的产卵数无显著差异。处理雌虫与未处理雄虫配对后以及处理雄虫与未处理雌虫配对后,雌虫产卵的孵化率均显著低于对照处理,但不同处理时间后卵的孵化率无显著差异; 两种配对处理所产卵的孵化率无显著差异。据此得出结论：水菖蒲根茎提取物β-细辛醚为神经毒剂,可以减少四纹豆象的种群数量,具有开发为储粮害虫四纹豆象防治剂的潜力。     

不同温度下浸水对褐飞虱生存、繁殖及其寄主的影响

不同温度下浸水对褐飞虱卵孵化、若虫存活率、成虫取食和繁殖及其寄主水稻的影响研究结果表明 ,在相对低温2 2℃和 2 1～ 2 6℃的自然变温条件下 ,产卵后立即浸水对浙江和广西 2个褐飞虱种群的卵孵化影响均不明显 ,而在产卵后4 d浸水对浙江种群的卵孵化有显著的抑制作用。 2 8℃浸水 5d和 35℃浸水 1 d后卵孵化率显著下降且孵化进程延长。卵浸水后的初孵若虫的存活率随卵浸水时间的延长明显下降。稻株浸水对其体内所含的昆虫必需氨基酸影响较大 ,其总量减少 ,而稻株内可溶性糖含量却显著增加 ,导致褐飞虱在浸水稻株上的若虫生存率、成虫取食量和繁殖力均明显下降     

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。     

高温对油松毛虫卵发育的影响

将油松毛虫Dendrolimustabulaeformis卵在不同高温下处理80min后的试验结果表明,短时(80min)高温(4 0℃)对卵的孵化没有显著影响,但40℃高温的短时(80min)处理,却能显著缩短其发育历期,降低孵化率。将卵置于3 4℃下处理不同时间(0～4h)后移至40℃下80min ,再放回到2 8℃下的试验结果表明,卵历期有随着处理时间的增加而延长的趋势。在40℃下处理不同时间对卵的发育和孵化有显著影响,延长处理时间对卵孵化不利,连续处理8h后卵不能孵化。油松毛虫初产卵持续放置在≥3 4℃高温下不能孵化。     

延迟交配对昆虫生殖行为的影响以及与性信息素防治害虫的关系

对鳞翅目昆虫延迟交配对昆虫生殖力、卵孵化率、交配成功率、成虫寿命等进行了总结。雌虫延迟交配降低雌虫的生殖力、卵的孵化率及与雄虫成功交配率,但可以延长雌虫寿命。雄虫延迟交配降低雌虫的生殖力、卵的孵化率、产卵时间,雄虫的精子质量下降但寿命有所增加。已发现延迟交配在迷向法中控制害虫起着重要的作用,对进一步认识迷向法中不同作用机理以及延迟交配在迷向法防治害虫中的潜力进行了探讨。     

交配对小地老虎成虫寿命和繁殖的影响

通过室内饲养小地老虎,研究了交配对其成虫寿命和繁殖的影响.结果 表明,小地老虎成虫的寿命随其交配状况而有所变化,无论雌蛾还是雄蛾,未能得到及时交配时,则寿命稍长些,交配过的雌蛾产卵前期缩短、产卵期延长、产卵量增大.小地老虎的交配次数对其产卵量和幼虫孵化率有明显的影响,0次交配的产卵量最低,并且产的是不育卵,均不能孵化;随着交配次数的增加,其产卵量和幼虫孵化率都显著增大.     

温度对三突花蛛个体发育和生殖行为的影响

本研究结果表明:(1)三突花蛛(Misumenops tricuspidatus)的卵在35℃恒温条件下不能孵化。(2)在15°-32℃恒温条件下随温度升高历期逐渐缩短,脱皮次数也随之减少,以25°-30℃恒温条件下幼蛛的存活率较高;同一温度梯度下雄蛛的平均历期均短于雌蛛。(3)在28℃恒温条件下产卵率为最高,产卵量最高;25℃下孵化率最高,30℃下生育力最强。(4)三突花蛛在繁殖力上具有种的稳定性。     

温度对家蝇广州种群成虫繁殖力及卵黄蛋白发生的影响

研究了不同温度对家蝇(Musca domestica L.)广州种群繁殖力及卵黄蛋白发生的影响,旨在为利用家蝇广州种群大规模高效养殖提供技术支持。选同一天刚羽化的健康雌、雄蝇,分别置于20、24、28、32和36℃环境下单对饲养,重复6次。每天测定成虫日产卵量、卵孵化率及死亡数等,统计家蝇单雌产卵量、卵孵化率、成虫寿命、产卵前期和产卵期;同时自雌蝇羽化第一日起,连续15 d,每天每个温度处理下取雌蝇3头,采用间接酶联免疫(indirect enzyme-linked immunosorbentassay,ID-ELISA)法测定5种温度下雌蝇每日卵黄蛋白合成量及羽化后前15 d卵黄蛋白合成总量。结果表明,温度对家蝇成虫繁殖力影响显著。产卵量以24℃环境下最高(1 921.17粒/雌),24～28℃时产卵量显著下降。28℃时卵孵化率最高(93.48%),高或低于此温度,卵孵化率显著下降,当温度达36℃时,孵化率仅为60.78%。雌蝇在20～28℃范围内产卵期差异不显著,32℃及以上温度下,雌蝇产卵期显著缩短。产卵前期以20℃最长(9.83 d),28℃最短(3.00 d),高于28℃产卵前期又显著延长。雌、雄蝇寿命均随着温度升高而显著缩短。温度对广州种群雌蝇羽化后前15 d的卵黄蛋白合成影响显著,24℃下前15 d合成的总卵黄蛋白最高(1 683.15μg/雌),其次为28℃(1 591.95μg/雌),20℃最低(232.81μg/雌)。家蝇广州种群在24～28℃繁殖效率最高。     

Paternity analysis in an egg‐carrying aquatic insect Appasus major (Hemiptera: Belostomatidae) using microsatellite DNA markers

The giant water bug Appasus major exhibits a peculiar reproductive behavior where females lay eggs on the backs of males. A male and female pair performs frequent repeat copulations during the oviposition behavior, and the male carries the deposited eggs until hatching. Such characteristic behaviors predict that the eggs are fertilized by the brooding males. If males carry eggs of other unrelated males, the egg carrying will drastically decrease the fitness of the carriers. In this study, we examined genetic relationships between the 489 eggs and nine males carrying them collected from the field, using microsatellite DNA markers. We revealed that in total, 28.4% of the eggs were of other male origin. This is the first report of frequent brood parasitism in an aquatic egg‐carrying hemipteran insect. The brood parasitism is adaptive for the females probably because it enables them to increase the chance of oviposition, or it can equalize motility risk of the eggs of each mate.     

Effect of clutch size on male egg-fanning behavior and hatching success in the goby, Eviota prasina (Klunzinger)

In fish that exhibit paternal care, the females often choose their mates on the basis of male traits that are indicative of the parental ability of the males. In a marine goby, Eviota prasina, males tend their eggs within their nests until hatching, and females prefer males that have longer dorsal fins and exhibit courtship behavior with a higher frequency as their mates. In order to clarify the relationship between these sexually selected traits and the parental ability of males of E. prasina, the factors affecting the hatching success of eggs within male nests and the male parental care behavior were examined in an aquarium experiment. Females spawned their eggs in male nests and the clutch size of females showed a high individual variation (range = 88-833 eggs). The hatching success of eggs within male nests showed a positive correlation with the time spent by males in fanning eggs and the clutch size. In contrast to the prediction, however, the hatching success did not show a significant correlation with the sexually selected traits, i.e., the male dorsal fin length and the frequency of courtship displays. Moreover, multiple regression analysis indicated that the time spent by the males in fanning was the most important factor affecting the survival rate of the eggs. The time spent by males in fanning behavior was influenced by the clutch size within their nests; the fanning behavior of males occurred with a higher frequency when they tended larger clutches. Males are required to invest a greater effort in egg-tending behavior to achieve a higher hatching success when they receive larger clutches, probably due to the greater reward for their parental behavior. Based on their mate choice, females may obtain other benefits such as high quality offspring.     

Environmental Effects on Male Reproductive Success and Parental Care in the Florida Flagfish Jordanella floridae

Models of optimal parental care predict that parental investment should depend on offspring value or the effect parental care has on offspring benefits. Few studies have examined the effect of external factors that influence offspring survival and the cost of care. In this study on the Florida flagfish (Jordanella floridae), a species with male parental care, we examined whether environmentally induced changes in care result from changes in egg requirements or in parental costs. We manipulated salinity and temperature, as these factors are known to affect the metabolic rate in both eggs and parents. We predicted that if the change in care behavior is determined by costs to the male then it should be paralleled by changes in non‐egg‐directed behavior. Conversely, if egg‐directed behavior changes independently of other behavior it would suggest that behavior is determined primarily by egg requirements. In addition we examined patterns of mating success under the assumption that if male care is affected by environmental factors then female preferences may change accordingly. Males decreased egg‐directed behavior (fanning and cleaning of eggs) at high salinity. Non‐egg‐directed behavior was unaffected by salinity. Temperature had no effects on behavior. Thus, we conclude that changes in egg demands are primarily responsible for the observed results. Successful males were bigger and more aggressive. This suggests that male dominance was an important determinant of male mating success. Unsuccessful males showed significantly more variation in number of red stripes with respect to salinity than successful males. Unsuccessful males may be less able to regulate color expression under varying environmental conditions, in which case color may be an indicator of male quality. We replicated the experiment early and late in the season. Males did not change their effort in care over the season. However, care (fanning) in the absence of eggs increased towards the end of the season. Since pre‐mating fanning was positively correlated to a male’s eventual mating success we conclude that males increased their effort to attract mates late in the season.     

Components of care: are they honest signals of parental care quality?

It has been argued that male parental care provides direct benefits to females and therefore should be under sexual selection. Given this, we expect signals that honestly indicate the quality of care to be favoured by selection. One such potential signal is care itself. Fish have several features that make them excellent model systems for studying the evolution and dynamics of parental care. We use the flagfish, Jordanella floridae , as a model to evaluate these general ideas. Males of this species guard, clean and fan empty nests and then eggs. Females prefer males that fan more (1) before spawning and (2) when eggs are newly received. When single males and females were paired, males that fanned and visited their nests more prior to spawning were more likely to be mated. Furthermore, among successful males, rates of fanning in the first day after spawning were correlated with the number of eggs received in the future (but not current egg numbers). We then considered whether these two putative signals were correlated and whether males that fan more in these contexts actually have higher egg survivorship. We found no correlation between nest fanning rates before and after spawning and neither 'signal' was predictive of variation in egg survivorship among mated males. We further considered whether pre‐spawning fanning rates were predictive of hatching success in an experiment in which single males were allowed to establish nests and provided eggs. We found little evidence that fanning is an honest signal of care quality and discuss alternative explanations. In particular, we discuss patterns of care elaboration in light of our results.     

Context-Dependent Plastic Response during Egg-Laying in a Widespread Newt Species

Previous research on predator-induced phenotypic plasticity mostly focused on responses in morphology, developmental time and/or behaviour during early life stages, but the potential significance of anticipatory parental responses has been investigated less often. In this study I examined behavioural and maternal responses of gravid female smooth newts, Lissotriton vulgaris, in the presence of chemical cues originating from invertebrate predators, Acilius sulcatus water beetles and Aeshna cyanea dragonfly larvae. More specifically, I tested the extent of oviposition preference, plasticity in egg-wrapping behaviour and plasticity in egg size when females had the possibility to lay eggs at oviposition sites with and without predator cues during overnight trials. I found that individuals did not avoid laying eggs in the environment with predator cues; however, individuals that deposited eggs into both environments adjusted the size of the laid eggs to the perceived environment. Females deposited larger eggs earlier in the season but egg size decreased with time in the absence of predator cues, whereas individuals laid eggs of average size throughout the investigated reproductive period when such cues were present. Also, egg size was found to be positively related to hatching success. Individuals did not adjust their wrapping behaviour to the presence of predator cues, but females differed in the extent of egg-wrapping between ponds. Females’ body mass and tail depth were also different between ponds, whereas their body size was positively associated with egg size. According to these results, female smooth newts have the potential to exhibit activational plasticity and invest differently into eggs depending on temporal and environmental factors. Such an anticipatory response may contribute to the success of this caudate species under a wide range of predator regimes at its natural breeding habitats.     

杀扑磷抗性获得对奥氏钝绥螨发育历期与繁殖能力的影响

为探索杀扑磷抗性获得对奥氏钝绥螨Amblyseius womersleyi Schicha发育历期与繁殖能力的影响,研究了在25℃与30℃温度下,奥氏钝绥螨的杀扑磷抗性系与敏感系的发育历期与繁殖能力。结果表明：奥氏钝绥螨的杀扑磷抗性系与敏感系的交配产卵行为习性没有差异。在25℃与30℃温度下,奥氏钝绥螨的各发育历期、产卵期、产卵高峰期,每雌日产卵量与总产卵量,卵孵化率及雌雄成螨性比等,在杀扑磷抗性系与敏感性系之间无明显差异。结果说明杀扑磷抗性获得对奥氏钝绥螨的发育历期与繁殖能力没有明显影响。     

Offering offspring as food to cannibals: oviposition strategies of Amazonian poison frogs (Dendrobates ventrimaculatus)

Species utilizing distinct resources for offspring production often show plasticity in reproductive strategies as a function of resource quality. For species using ephemeral pools, strategies are mainly shaped by a time constraint related to pool stability, resource availability and the colonizing community. We studied reproductive strategies in Amazonian poison frogs (Dendrobates ventrimaculatus) that are characterized by oviposition in distinct, small and resource-limited water bodies in leaf axils of plants and the transport of newly hatched tadpoles on the back of males to similar water bodies. Cannibalism of eggs by tadpoles was found to be the main cause of egg mortality. Typically, at the end of the rainy season new clutches of eggs were deposited in water bodies already containing a tadpole. Manipulation of the available number of water bodies showed that this observation did not result from resource limitation. We conclude that D. ventrimaculatus has a plastic reproductive strategy that includes provisioning its tadpoles with fertilized eggs as a function of desiccation risk of water bodies housing its offspring. Provisioning behavior is expected to increase developmental rate and, therefore, chances of metamorphosis for tadpoles that hatched towards the end of the rainy season. The plastic food provisioning strategy may be an important evolutionary link to bi-parental and female care with development of obligate unfertilized egg provisioning in the genus Dendrobates.     

牛蒡抗虫活性及抗虫成分的初步研究

在水温(23±0.5)℃、pH 7.0～8.0、溶解氧＞5 mg· L-1的条件下,研究孵化过程中不同盐度对拟目乌贼胚胎发育和孵化率的影响.结果表明,拟目乌贼卵透明略带奶油色,近椭圆形,短径为0.596～1.758 cm,长径为1.452～3.136 cm,刚产出的卵重约2g;孵化完成时,卵膜内的重量达到4.5g.在盐度为28‰时,经过28～30 d孵化,卵的短径和长径平均分别增加了0.601、0.615 cm,孵化率为57.0％;盐度为23‰时,卵的长径和短径也相应增加,增幅分别为0.567、1.263 cm,孵化率为13.5％;盐度为33‰时,经过28～30 d孵化,卵短径平均增长0.150 cm,而长径却缩短了0.141 cm,孵化率为9.5％;在盐度为13‰、18‰、38‰和43‰条件下,胚胎停止发育,孵化率为0.结果表明,拟目乌贼属于狭盐性种类,盐度变化对拟目乌贼胚胎发育和孵化有直接影响.     

Reduction in egg hatch after a sublethal dose of chlorfluazuron to larvae of the common cutworm, Spodoptera litura

Abstract.  The effects of a sublethal dose of chlorfluazuron on egg hatching in Spodoptera litura are examined under laboratory conditions. When LD₁₀ of chlorfluazuron is topically applied to newly moulted fifth-instar larvae of either sex, a significant reduction in both the number of eggs laid and subsequent hatching is observed after mating but no significant differences in daily of oviposition are observed when compared with the controls. In addition, examination of the unhatched eggs reveals that the number of unfertilized eggs is greater than those that were fertilized but there are significantly more unfertilized eggs laid by treated insects. Interference by chlorfluazuron, transferred by copulation through sperm fluids or ova, appears improbable. All the fertilized unhatched eggs in the treated crosses die at an earlier stage than those of the controls. In the female-treated crosses, the egg size is significantly reduced compared with the control or male-treated crosses. During mating, the treated-males transferred significantly lower-weight spermatophores into the females. The weight of spermatophores transferred by untreated males is the same to both treated and untreated females. The duration of mating is not affected by chlorfluazuron treatment.