昆虫假死行为研究进展

假死是昆虫重要的防御行为,与生存策略密切相关.昆虫受到天敌或类似天敌的外部物理刺激时,足、触角等附肢收缩,强直静止,自发进入假死状态.近年来,昆虫假死行为相关的研究逐渐增多,进展明显,明确了多种昆虫假死的发生时间、发生频率、刺激方式和诱发因素等特征,涉及臭椿沟眶象Eucryptorrhynchus brandti、赤拟...     

不同波段LED光源对毛健夜蛾行为的影响

为探明不同波段LED光对毛健夜蛾Brithys crini (Fabricius)行为的影响, 在实验条件下观察了4种不同波段（红光： 620~625 nm; 绿光： 520~523 nm; 蓝色： 465~467 nm; 白光： 460~465 nm）LED光源下毛健夜蛾幼虫的假死、 爬行、 静止、 取食、 排便、 瞭望及其他行为和成虫交配及产卵行为。结果表明： （1）毛健夜蛾幼虫在红光、 绿光、 蓝光和白光4种LED光源下, 爬行、 静止和取食行为时间分配差异极显著（爬行、 静止和取食： P=0.000）, 红光组爬行的时间占98.06%, 绿光组取食时间占83.65%, 蓝光组爬行和静止时间占91.56%, 白光组爬行时间占61.16%; 爬行、 静止、 取食、 瞭望及其他行为发生率差异显著, 红光组和白光组爬行行为发生率最高, 分别为47.37%和32.00%, 绿光组取食行为发生率最高为40.00%, 蓝光组爬行行为发生率最高为32.35%; （2）毛健夜蛾跌落幼虫在4种LED光源下, 假死发生率差异不显著, 但假死持续时间有显著性差异, 红光组假死持续时间显著长于蓝光组和白光组; （3）4种LED光源处理后, 交配和未交配的单雌产卵量无显著差异; （4）第1-2天的暗期分别使用4种光源, 则交配和产卵高峰均出现在第3天的暗期, 而第1-2天的暗期不使用光源, 则交配和产卵高峰出现在第1天的暗期。这些研究结果初步揭示了不同波段光源对毛健夜蛾行为影响不同。     

毛健夜蛾幼虫假死行为诱导因子研究

【目的】探明毛健夜蛾Brithys crini Fabricius幼虫另类假死行为的规律和特点。【方法】在实验室条件下观察毛健夜蛾幼虫体重、连续刺激、作用力的大小、背景声音和背景LED光色对假死发生率和假死持续时间的影响。【结果】(1)假死持续时间有随幼虫体重增加而延长的趋势,但相关性不显著。(2)假死持续时间有随刺激次数增加而缩短的趋势,与刺激次数呈显著性负相关;前10次刺激的平均假死持续时间(85.6 s)显著长于后10次(67.3 s)。(3)2、5和10 N力处理组间假死持续时间(分别为82.3、97.4和78.3 s)无显著差异,但三者均显著短于6 N力处理组的假死持续时间(157.0 s)。(4)风声处理组假死持续时间(65.6 s)显著短于鸟鸣声和蛙叫声处理组(分别为144.8 s和134.1 s)。(5)不同颜色背景LED光源处理下,假死持续时间有显著差异性,红色闪光、红色、黄色、绿色、白色和蓝色处理组假死持续时间分别为54.7、64.3、82.7、90.6、96.9、112.3 s。各处理假死发生率没有显著性差异。【结论】毛健夜蛾幼虫假死行为可因内外环境因素不同而异。     

动物的防御行为

防御行为可分为初级防御和次级防御,共有１０种防御方法,即穴居,隐蔽,警戒色,拟态,回缩,逃循,威吓,假死,转移攻击部位和反击。     

胸窗萤的防卫行为：反射性出血及翻缩腺反应

为了探讨胸窗萤Pyrocoelia pectoralis Oliver, 1883的防卫行为, 对成虫的反射性出血行为及幼虫的翻缩腺体形态进行了研究。结果表明： 胸窗萤具有复杂的多重防卫行为策略。成虫利用闪烁、 假死、 反射性流血进行防卫, 幼虫则利用闪烁、 假死和微小的翻缩腺体进行防卫。反射性流血发生在雄成虫的前胸背板和鞘翅边缘, 而雌成虫仅在前胸背板边缘观察到有反射性流血行为。扫描电镜观察到直径大约32 μm的圆坑状结构环绕前胸背板或鞘翅边缘一圈。雌虫鞘翅牙也具有相似的圆坑状结构。幼虫具有9对乳头状的翻缩腺体, 位于中胸、 后胸和第1～7节侧板上。超薄切片发现, 腺体表面的棒状结构内部中空, 棒状结构连接一个发达的分泌细胞。细胞内连接棒状结构的部位着生致密的管状内质网。行为学实验发现, 胸窗萤血液对蚂蚁具有非常有效的拒避作用。     

平利短肛棒（虫）生物学特性研究

1997年至 1998年 ,我们在四川南充市金城山林场对平利短肛棒 (BaculumpinglienseChenetHe)的生物学特性及天敌进行了研究 ,结果表明 :该虫一年发生一代 ,以卵在卵囊内越冬 ,翌年 4月初开始孵化 ,4月中旬为孵化盛期 ,若虫共 5龄 ,6月下旬出现成虫 ,7月上旬到 9月下旬为产卵期 ,成虫 7月底开始死亡 ,终见于 9月下旬 ;具拟态、保护色、假死性和若虫断足能再生等奇特生命现象 ,但没有竹节虫常见的孤雌生殖行为 ;其天敌主要有鸟类、蜘蛛和捕食性昆虫等共 17种。     

平利短肛棒Xiu生物学特性研究

1997年至1998年,我们在四川南充市金城山林场对平利短肛棒Xiu（Baculum pingliense Chen et He）的生物学特性及天敌进行了研究,结果表明：该虫一年发生一代,以卵在卵囊内越冬,翌年4月初开始孵化,4月中旬为孵化盛期,若虫共5龄,6月下旬出现成虫,7月上旬到9月下旬为产卵期,成虫7月底开始死亡,终见于9月下旬;具拟态、保护色、假死性和若虫断足能再生等奇特生命现象,但没有竹节虫常的孤雌生殖行为;其天敌主要有鸟类、蜘蛛和捕食性昆虫等共17种。     

蜜蜂采集及其信息传递的行为机制研究进展

蜜蜂的采集行为是蜜蜂众多社会行为中一种较复杂的行为,涉及信息评估、信息传递、学习记忆及能量代谢等不同的行为过程。研究蜜蜂采集及信息交流系统的分子机制,不仅利于蜜蜂的理论研究和蜂产业的发展,还为人类语言及信息交流系统的研究提供借鉴。本文从行为、感觉基础及分子机制等不同研究层面,综述了近年来对蜜蜂采集及信息传递行为的研究进展,并提出了研究设想,以期为深入研究蜜蜂的采集行为及其信息传递行为的分子机制提供参考。     

山胡椒的研究与利用

一、概况山胡椒又叫牛筋条、雷公树、假死柴、老来红等多种名称,是一种有多种用途的植物,属樟科山胡椒属(Lindera glauca),分布我国台湾、福建、广东、广西、湖南、湖北、江苏、浙江、江西、山东、河南、安徽、四川、贵州、山西、陕西、甘肃十七个省(区)。山胡椒的用途很广,但在工农业上的综合利用还是近年的研究成果。试验研究证明:山胡椒的     

血液稳态本构方程参数的研究

对生理及一些病理情况下的血液本构方程进行了研究,提出一种简单实用的本构方程研究方法,用此新方法对实验数据进行了拟合,发现Ｑｕｅｍａｄａ方程与Ｋ－Ｌ方程与人及犬等的血液流变行为较为一致,而且由这两种方程得到的组合本构参数有较明确的物理意义,可用来表示红细胞聚集等流变行为,可望成为临床的检测指标     

Effects of starvation on death‐feigning in adult Eucryptorrhynchus brandti (Coleoptera: Curculionidae)

In insects, death‐feigning is an effective defence strategy. Eucryptorrhynchus brandti, a major borer pest in China, has a weak flight ability and exhibits obvious death‐feigning behaviour when disturbed. Despite a large number of studies of its biological and ecological properties as well as control methods, the death‐feigning behaviour has not been specifically described. In laboratory conditions, we recorded the survival rate under starvation and feeding conditions and evaluated the effect of starvation on the duration and occurrence of death‐feigning. In a continuous experiment, we examined variation in the death‐feigning duration every day over 7 day. Then, we evaluated the effects of starvation for 3, 6 and 9 day in a non‐continuous experiment and further observed variation in the death‐feigning intensity. We found that starvation significantly affected the survival rate. Survival time was significantly longer in the starvation group than in the feeding group, and females had longer survival times than males (female: 14 day, male: 8 day). In the continuous experiment, starved E. brandti had the longest duration of death‐feigning at 2 day, followed by a significant decrease. In the non‐continuous experiment, the duration and proportion of death‐feigning decreased significantly as the duration of starvation increased and were significantly lower than feeding. These observations suggest that starvation is a non‐negligible factor in the death‐feigning behaviour of E. brandti adults, facilitating the interpretation of future ecological and behavioural data of thanatosis.     

Death feigning as an adaptive anti‐predator behaviour: Further evidence for its evolution from artificial selection and natural populations

Death feigning is considered to be an adaptive antipredator behaviour. Previous studies on Tribolium castaneum have shown that prey which death feign have a fitness advantage over those that do not when using a jumping spider as the predator. Whether these effects are repeatable across species or whether they can be seen in nature is, however, unknown. Therefore, the present study involved two experiments: (a) divergent artificial selection for the duration of death feigning using a related species T. freemani as prey and a predatory bug as predator, demonstrating that previous results are repeatable across both prey and predator species, and (b) comparison of the death‐feigning duration of T. castaneum populations collected from field sites with and without predatory bugs. In the first experiment, T. freemani adults from established selection regimes with longer durations of death feigning had higher survival rates and longer latency to being preyed on when they were placed with predatory bugs than the adults from regimes selected for shorter durations of death feigning. As a result, the adaptive significance of death‐feigning behaviour was demonstrated in another prey–predator system. In the second experiment, wild T. castaneum beetles from populations with predators feigned death longer than wild beetles from predator‐free populations. Combining the results from these two experiments with those from previous studies provided strong evidence that predators drive the evolution of longer death feigning.     

Genetic correlation between behavioural traits in relation to death-feigning behaviour

Individuals frequently behave in a consistent manner across time or in different situations. We examined the repeatability of duration of death-feigning anti-predator behaviour when attacked, and then carried out artificial selection for duration to calculate its heritability and examine correlated responses to selection in activity levels, in the confused flour beetle, Tribolium confusum. Three replicates of two strains were established by artificial selection for more than 17 generations: S strains exhibited shorter duration and lower frequency of death feigning while L strains exhibited longer duration and higher frequency of death feigning. Duration of death feigning clearly responded to selection, and significant value of realized heritability was detected in all replicates of the two strains. Examination of locomotor activity levels over a constant period showed that S strains had higher locomotor activity levels than L strains. No significant differences between the sexes were observed. Our study thus demonstrates heritability of death feigning and the existence of a negative genetic correlation between intensity of death feigning and activity level.     

The effect of mass‐rearing on death‐feigning behaviour in the sweet potato weevil (Coleoptera: Brentidae)

The aim of our study was to examine the effect of mass‐rearing, in which there is no exposure to predators, on antipredator traits of insects for improving sterile insect technique programs. The duration of death‐feigning (antipredator behaviour) in sweet potato weevil Cylas formicarius (Summers) (Coleoptera: Brentidae) after mass‐rearing for 71 generations were compared with those in wild strain. There was no significant difference in the duration of death‐feigning between wild and mass‐reared strains. This indicated that the death‐feigning behaviour of mass‐reared strain was maintained for 71 generations even in the absence of predators. We discuss the reasons why death‐feigning behaviour is maintained after mass‐rearing.     

Positive genetic correlations between life-history traits and death-feigning behavior in adzuki bean beetle (Callosobruchus chinensis)

Usually, several traits in organisms are genetically linked with each other; thus, correlated responses to selection are generally observed. Anti-predator behaviors may be genetically correlated with other traits such as life-history. We compared the life-history traits of individuals derived from two regimes artificially selected for the duration of death feigning in the adzuki bean beetle, Callosobruchus chinensis. The two-way selected regimes include the L-lines with stronger intensity (longer duration and higher frequency) and the S-lines with weaker intensity (shorter duration and lower frequency) of death feigning. L-lines exhibited greater longevity, higher rates of emergence, laid bigger eggs and greater reproductive effort, and also had a tendency of faster development. Fecundity was not significantly different between L- and S-lines. These results provide the novel possibility that death feigning is a potentially advantageous anti-predator behavior that, through a positive genetic correlation with some life-history traits, can bring a higher fitness to an individual adopting this behavior. This novel aspect might explain why death-feigning behavior is prevalent in various taxonomic animal groups.     

A Behavioral Syndrome in the Adzuki Bean Beetle: Genetic Correlation Among Death Feigning,Activity, and Mating Behavior

When studying animal behavior, it is often necessary to examine traits as a package, rather than as isolated units. Evidence suggests that individuals behave in a consistent manner across different contexts or over time; that is, behavioral syndromes. We compared locomotor activity levels and mating success between beetles derived from two regimes artificially selected for the duration of death‐feigning behavior in the adzuki bean beetle, Callosobruchus chinensis. The two selection regimes comprised strains with higher (L) and lower (S) intensity (frequency and duration) of death‐feigning behavior, respectively. We found that S strains had higher activity levels than L strains for both sexes, i.e., there is a negative genetic correlation between death feigning and activity. In addition, we found that S strains had higher mating success than L strains, presumably due to higher activity, in males but not in females. We thus demonstrate that death feigning is genetically correlated to mating behavior in males but not females in this species, suggesting that behavioral correlations may not always reflect in the same way in both sexes.     

Adaptive significance of death feigning posture as a specialized inducible defence against gape-limited predators

Death feigning is fairly common in a number of taxa, but the adaptive significance of this behaviour is still unclear and has seldom been tested. To date, all proposed hypotheses have assumed that prey manage to escape predation by sending a death-mimicking signal, although death-feigning postures are markedly different from those of dead animals. Moreover, the efficacy of this technique may largely depend on the foraging mode of the predator; death feigning seldom works with sit-and-wait predators that make the decision to attack and consume prey within a very brief time. We examined whether death feigning in the pygmy grasshopper Criotettix japonicus Haan was an inducible defence behaviour against the frog Rana nigromaculata, a sit-and-wait, gape-limited predator. The characteristic posture assumed by the grasshopper during death feigning enlarges its functional body size by stretching each of three body parts (pronotum, hind legs and lateral spines) in three different directions, thereby making it difficult for the predator to swallow the prey. Our result is the first consistent explanation for why death-mimicking animals do not always mimic the posture of dead animals.     

Age‐dependent investment in death‐feigning behaviour in the sweetpotato weevil Cylas formicarius

Because life‐history theory predicts that risky behaviours such as mating should increase as life expectancy decreases, predatory avoidance is expected to decrease with age. However, this prediction has not been examined. In the present study, the effect of age on death‐feigning behaviour, a form of predatory avoidance behaviour in the sweetpotato weevil Cylas formicarius (Summers) (Coleoptera: Brentidae), is investigated by performing a longitudinal study. Because the effects of mating history and age usually cannot be distinguished, mating history is controlled. The results show that only female weevils decrease the investment in death‐feigning behaviour with age, whereas male weevils do not show any age‐related change. In addition, death‐feigning behaviour of mated females is longer than that of virgin females, possibly because additional mating partners would be not needed by mated females.     

Freezing or death feigning? Beetles selected for long death feigning showed different tactics against different predators

Prey evolve antipredator strategies against multiple enemies in nature. We examined how a prey species adopts different predation avoidance tactics against pursuit or sit‐and‐wait predators. As prey, we used three strains of Tribolium beetles artificially selected for short (short strain) or long (long strain) duration of death feigning, and a stock culture (base population). Death feigning is known to be effective for evading a jumping spider in the case of the long strains, while the present study showed that the long‐strain beetles used freezing against a sit‐and‐wait type predator, Amphibolus venator, in this study. The short‐ strain beetles were more easily oriented toward predators. The time to predation was also shorter in the short strains compared to the long strains. The results showed that, as prey, the short strains displayed the same behavior, escaping, against both types of predators. Traditionally, death feigning has been thought to be the last resort in a series of antipredator avoidance behaviors. However, our results showed that freezing and death feigning were not parts of a series of behaviors, but independent strategies against different predators, at least for long‐strain beetles. We also examined the relationship between a predator''s starvation level and its predatory behavior. In addition, the orientation behavior toward and predation rate on the prey were observed to determine how often the predatory insect attacked the beetles.     

Death feigning in the face of sexual cannibalism

Pre-copulatory sexual cannibalism by females affects male and female reproductive success in profoundly different ways, with the females benefiting from a meal and the male facing the risk of not reproducing at all. This sexual conflict predicts evolution of traits to avoid cannibalism and ensure male reproductive success. We show that males of the nuptial gift-giving spider Pisaura mirabilis display a remarkable death feigning behaviour--thanatosis--as part of the courtship prior to mating with potentially cannibalistic females. Thanatosis is a widespread anti-predator strategy; however, it is exceptional in the context of sexual selection. When the female approached a gift-displaying male, she usually showed interest in the gift but would sometimes attack the male, and at this potentially dangerous moment the male could 'drop dead'. When entering thanatosis, the male would collapse and remain completely motionless while retaining hold of the gift so it was held simultaneously by both mates. When the female initiated consumption of the gift, the male cautiously 'came to life' and initiated copulation. Death feigning males were more successful in gaining copulations, but did not have prolonged copulations. We propose that death feigning evolved as an adaptive male mating strategy in conjunction with nuptial gift giving under the risk of being victimized by females.