土垅大白蚁Macrotermes annandalei(Silvestri)采食品级的踪迹信息素

【目的】解析土垅大白蚁Macrotermes annandalei(Silvestri)采食行为中的踪迹信息交流机制。【方法】通过对其踪迹信息素进行化学和行为活性分析。【结果】土垅大白蚁兵蚁腹板腺源踪迹信息素的主要成分为顺-3-十二碳单烯醇-1((3Z)-dodec-3-en-l-ol,DOE),与工蚁的踪迹信息素化学结构完全相同。大兵蚁腺体当中DOE的含量最高,分别是大、小工蚁品级和小兵蚁品级DOE含量的3.88倍和3.78倍,与其在采食行为中的功能相适应。尽管小兵蚁的位置处于采食队伍的先锋,但小兵蚁的踪迹信息素含量与工蚁相当,不能起到召募采食的作用。行为观察和跟踪信息素行为活性表明大兵蚁具有通过分泌大量踪迹信息素召募工蚁品级的能力。【结论】土垅大白蚁依靠大兵蚁分泌大量踪迹信息素单一组分及其在采食队伍中的位置的变化来实现采食行为中的方向信息的快速传递交流。     

白蚁取食行为多型及其机理

对白蚁取食行为的研究涉及5科18属38种白蚁。其取食行为多型可归纳为3类:(1)工蚁主导型:采食活动基本上由工蚁完成,兵蚁不参与或仅极少数个体参与,食物侦查或保护采食工蚁的职能不显著;(2)工蚁-兵蚁协同型:这是白蚁采食组织的常见类型,兵蚁成为采食队伍的固定成员,负责采食活动的安全侦查与防卫、食物源侦查等工作;(3)假工蚁主导型:由于尚未分化形成专职的工蚁,因而大龄幼蚁(广义的假工蚁)成为采食活动的主力,同时兼有巢内的保护职能。在食物加工和分配过程中,低等白蚁的幼蚁在未获得消化纤维素能力前主要通过肛交哺获得营养物质和共生物,且肛交哺是新蜕皮个体重新获得共生鞭毛虫的途径。高等白蚁幼龄工蚁负责食物加工、依赖型品级通过口交哺获得营养物质。白蚁采食活动中的行为多型受踪迹信息素控制,不同品级个体腹板腺有明显分化;不同品级和发育阶段个体食性分化与消化道结构、消化酶活性密切相关;保幼激素影响交哺行为以及消化酶基因表达。本文在评述研究进展的同时,对进一步研究提出了展望。     

白蚁踪迹信息素研究进展

近年来, 固相微萃取技术的使用显著促进了白蚁踪迹信息素研究的开展。目前, 已有77种白蚁的踪迹信息素得到研究, 常见化学成分为十二碳单烯醇、 十二碳二烯醇和十二碳三烯醇, 其次为新松柏烯。已经鉴定的踪迹信息素主要为单组分或双组分系统。白蚁踪迹信息素由腹板腺分泌, 除澳白蚁科的达氏澳白蚁Mastotermes darwiniensis具有3个腹板腺外, 现存的白蚁均具有1个腹板腺, 位于第4或第5腹节。所有腹板腺都具有类型Ⅰ和Ⅱ两类细胞, 原白蚁亚科（Termopsinae）、 齿白蚁科（Serritermitidae）、 鼻白蚁科（Rhinotermitidae）种类的腹板腺还具有类型Ⅲ细胞。踪迹信息素的生物合成还缺乏研究, 推测有甲羟戊酸、 脂肪醇和饱和表皮烃3种途径。白蚁踪迹信息素的简约性十分显著, 不同地理分布、 生物生态习性以及一些系统距离较远的种类具有相同和密切相关的踪迹信息素。对于许多种类, 相同的信息化合物具有踪迹信息素和配对性信息素双重功能。白蚁踪迹信息素种特异性和简约性的适应意义和进化机制需要进一步研究。     

白蚁信息素研究进展

白蚁是最古老的社会性昆虫, 其社会性的维持需要信息素的相互作用。本文回顾了近年来国内外白蚁信息素研究的最新进展, 内容涉及白蚁踪迹信息素、 性信息素、 告警信息素和促食信息素的功能、 化学成分及产生信息素的外分泌腺。白蚁分泌信息素的腺体主要有背板腺、 腹板腺、 后腹板腺、 额腺和唾腺。绝大多数白蚁信息素是挥发性物质。白蚁在化学通讯上存在节俭策略, 即同一种化合物由不同的白蚁种类的不同外分泌腺分泌, 可具有不同的功能。总结了各类信息素在白蚁物种间、 同一物种的品级间和性别间的异同和作用方式, 强调了白蚁信息素的反应阈值、 最佳浓度、 有效期和物种特异性对其功能的影响。目前对白蚁信息素的研究尚处于起步阶段, 其研究成果对等翅目系统发育研究和白蚁防治具有重要的意义。文章最后展望了白蚁信息素在白蚁防治上的应用前景。     

白蚁表皮碳氢化合物研究进展

近年来, 固相微萃取等现代技术的使用显著促进了白蚁表皮碳氢化合物研究的开展。至今, 已有约29种白蚁的表皮碳氢化合物组分得到鉴定, 分属于木白蚁科、 鼻白蚁科、 原白蚁科和白蚁科, 其组分主要为正烷烃、 含有不同数量甲基的支链烷烃及少量烯烃。白蚁表皮碳氢化合物不仅具有一定的科、 属特异性, 大多数种类还具备特有组分, 表明其可作为种间识别的指标。表皮碳氢化合物组分在种内个体识别方面的作用, 在低等白蚁中多获得了支持性结果, 但也有研究认为在这些种类中表皮碳氢化合物不是种内个体识别（同巢个体识别）的唯一指标。发现其与品级分化的相关是近年来白蚁表皮碳氢化合物研究的重要进展。有些种类表皮碳氢化合物的年消长与生殖蚁的分化有关; 而另一些种类生殖蚁含有表皮碳氢化合物特有组分, 其含量与生殖蚁的生殖状态有关, 提示其可能在品级分化中发挥重要作用。作为研究白蚁品级分化和维持机理的新方向, 表皮碳氢化合物值得进一步研究探索。     

集群数量和采食距离对储草期布氏田鼠警戒频次的影响

警戒行为是动物对环境中潜在危险做出的反应。为探究影响警戒行为的因素,作者在内蒙古锡林郭勒典型草原区进行了集群数量和采食距离对储草期自由生活状态下布氏田鼠(Lasiopodomys brandtii)警戒频次影响的实验。通过标志重捕法和人工去除法设定3个集群数量梯度(11只、6只和3只),利用人工食物站设置4个采食距离梯度(5 m、10 m、20 m、30 m),共12个梯度组合,每个组合分别观察60次采食过程,共计观察720次,并记录采食过程中的警戒频次。对数据进行双因素方差分析,集群规模和采食距离对布氏田鼠警戒行为频次均有极显著影响(P0.01)。随着集群数量减小,布氏田鼠单次采食的警戒频次显著增加;采食距离越远,单次采食的警戒频次越高;集群数量和采食距离之间还存在极显著的交互作用(P0.01)。集群数量增大意味着采食距离的增加,为保证储草效率,布氏田鼠种群会在增加集群数量和减小采食距离之间权衡,最终集群数量维持在中等水平,支持了最优集群理论。     

信息化合物对昆虫行为的影响

本文综述了来自寄主植物的挥发性物质和同种昆虫或异种昆虫释放的各种信息素及两者的协同作用的信息化合物对昆虫行为的影响。特别强调了寄主植物的气味物质和昆虫信息素协同作用在昆虫寻找寄主、求偶、交配及天敌在寄主识别过程中的重要地位。昆虫对寄主植物的识别是由于识别了植物气味的由一定组分、按照严格比例组成的化学指纹图。昆虫信息素与植物挥发性物质相结合为昆虫寻找求偶、交配场所提供更复杂或更全面的信息。许多昆虫只有在寄主植物或寄主植物气味存在时 ,才能释放性或聚集信息素。天敌在寄主识别、搜索及定位等一系列过程中 ,来自寄主的食料、寄主本身及两者的互作的信息化合物起重要的作用。研究信息化合物对昆虫行为的影响可以探索昆虫各种行为的内在机理 ,更好的了解寄主—昆虫—天敌三层营养关系的相互作用 ,对利用天然活性化合物防治害虫及生物防治提供理论依据     

烟蚜茧蜂对蚜虫信息素及烟草挥发物的触角电位反应

利用触角电位(EAG)技术测定了烟蚜茧蜂(Aphididius gifuensis)对蚜虫性信息素(荆芥醇和荆芥内酯)和报警信息素(反-β-法尼烯)以及烟草挥发性物质的电生理反应.结果表明:雌蜂和雄蜂对蚜虫性信息素、报警信息素、烟草挥发物均有反应,但雌雄蜂对这些化学信息物质的嗅觉敏感性存在差异,雌蜂对荆芥醇、荆芥内酯、顺-3-己烯-1-醇、反-2-己烯醛、水杨酸甲酯和里那醇的EAG反应都大于雄峰,证明雌雄蜂在利用寄主栖境中信息化学物质方面存在不同的策略,它们分别识别了不同的有关寄主的化学指纹图;烟蚜茧蜂对烟草气味组分具有不同的敏感性,对绿叶气味组分的EAG反应要强于对萜类化合物的反应,绿叶气味组分很有可能在其寻找桃蚜的过程中发挥远距离定向作用.     

黑翅土白蚁下唇腺解剖构造研究

本文利用显微解剖和测量,研究黑翅土白蚁Odontotermes formosanus下唇腺解剖构造及其在不同类型个体间职能的分化。黑翅土白蚁的下唇腺由左右对称的两部分组成,每侧构造由9～11个腺泡群、1个下唇腺囊及相关的导管组成。每侧的腺泡群导管与下唇腺囊导管首先汇合成分导管,两侧的分导管在舌基部后方汇合,形成一条主导管,主导管开口于舌基部下方。黑翅土白蚁下唇腺发达程度与个体的职能有关。有翅成虫下唇腺最发达,3龄无翅芽若虫下唇腺最小。巢内工蚁是口交哺物质的主要提供者,在下唇腺长度、腺泡直径及腺泡数量方面均极显著高于采食工蚁。兵蚁下唇腺及下唇腺囊转化为与防卫职能相关的器官。前兵蚁与兵蚁下唇腺囊均发达,老龄兵蚁下唇腺囊内充满黄色粘稠液体。冰冻保存后下唇腺明显缩小。冰冻保存后下唇腺腺泡直径的校正系数为1.19,腺泡群长度校正系数为1.14。     

哺乳动物主要嗅觉系统和犁鼻系统信息识别的编码模式

哺乳动物具有两套嗅觉系统, 即主要嗅觉系统和犁鼻系统。前者对环境中的大多数挥发性化学物质进行识别, 后者对同种个体释放的信息素进行识别。本文从嗅觉感受器、嗅球、嗅球以上脑区三个水平综述了这两种嗅觉系统对化学信息识别的编码模式。犁鼻器用较窄的调谐识别信息素成分, 不同于嗅上皮用分类性合并受体的方式识别气味; 副嗅球以接受相同受体输入的肾丝球所在区域为单位整合信息, 而主嗅球通过对肾丝球模块的特异性合并编码信息; 在犁鼻系统, 信息素的信号更多地作用于下丘脑区域, 引起特定的行为和神经内分泌反应。而在主要嗅觉系统, 嗅皮层可能采用时间模式编码神经元群, 对气味的最终感受与脑的不同区域有关。犁鼻系统较主要嗅觉系统的编码简单, 可能与其执行的功能较少有关。     

Synergy between social and private information increases foraging efficiency in ants

Insect societies integrate many information sources to organize collective activities such as foraging. Many ants use trail pheromones to guide foragers to food sources, but foragers can also use memories to find familiar locations of stable food sources. Route memories are often more accurate than trail pheromones in guiding ants, and are often followed in preference to trail pheromones when the two conflict. Why then does the system expend effort in producing and acquiring seemingly redundant and low-quality information, such as trail pheromones, when route memory is available? Here we show that, in the ant Lasius niger, trail pheromones and route memory act synergistically during foraging; increasing walking speed and straightness by 25 and 30 per cent, respectively, and maintaining trail pheromone deposition, but only when used together. Our results demonstrate a previously undescribed major role of trail pheromones: to complement memory by allowing higher confidence in route memory. This highlights the importance of multiple interacting information sources in the efficient running of complex adaptive systems.     

High Concentrations of the Alarm Pheromone Component,Isopentyl Acetate,Reduces Foraging and Dancing in <Emphasis Type="Italic">Apis mellifera</Emphasis> Ligustica and <Emphasis Type="Italic">Apis cerana</Emphasis> Cerana

A honeybee colony is a superorganism that has evolved precise communication systems, which allow the colony to gather information from numerous individuals and coordinate its behavior. Alarm pheromones, such as isopentyl acetate (IPA), the main component of sting alarm pheromone, play a critical role in the coordination of individual behaviors as well as colony communication in honeybee colonies. In this study, honeybees (Apis mellifera ligustica and Apis cerana cerana) were exposed to relatively high levels of IPA at a foraging site (6–8 bee equivalents) and inside their colony (28–58 bee equivalents) to investigate the influence of alarm pheromones on foraging activity and hive flight activity. IPA reduced the number of bees that flew out the hive, foraged, and waggle danced. Under both contexts in the hive and at the food source, IPA can therefore inhibit honey bee foraging and foraging communication.     

Trail Communication During Foraging and Recruitment in the Subterranean Termite Reticulitermes santonensis De Feytaud (Isoptera, Rhinotermitidae)

The search for food in the French subterranean termite Reticulitermes santonensis De Feytaud is organized in part by chemical trails laid with the secretion of their abdominal sternal gland. Trail-laying and -following behavior of R. santonensis was investigated in bioassays. During foraging for food termites walk slowly (on average, 2.3 mm/s) and lay a dotted trail by dabbing the abdomen at intervals on the ground. When food is discovered they return at a quick pace (on average, 8.9 mm/s) to the nest, laying a trail for recruiting nestmates to the food source. While laying this recruitment trail the workers drag the abdomen continuously on the ground. The recruitment trail is highly attractive: it is followed within a few seconds, by more nestmates, and at a quicker pace (on average, 6.4 mm/s) than foraging trails (on average, 2.9 mm/s). The difference between foraging and recruitment trails in R. santonensis could be attributed to different quantities of trail pheromone. A caste-specific difference in trail pheromone thresholds, with workers of R. santonensis being more sensitive to trails than soldiers, was also documented: soldiers respond only to trails with a high concentration of trail pheromone.     

CHEMICAL COMMUNICATION IN HAWAIIAN DROSOPHILA

We are interested in elucidating the extent to which lekking Hawaiian Drosophila species have diverged from their continental counterparts, which engage in sexual behavior at communal food sources, with regard to the chemical communication systems that the flies employ. Accordingly, we have analyzed flies from three closely related Hawaiian Drosophila species in the adiastola subgroup. These species are of interest because the males engage in a unique behavior: while courting, they raise their abdomens over their heads and emit anal droplets. Analysis of the flies' behavior, the hydrocarbons in males' anal droplets, and males' cuticular hydrocarbons suggest that females' responses to males may be mediated by cuticular pheromones and/or pheromones in males' extruded droplets that enable the females to distinguish conspecific from heterospeciflc males. Conversely, perception of cuticular hydrocarbons from conspecific females enables D. adiastola males to distinguish females from a closely related species from conspecific females. On the basis of these observations, we suggest that the adiastola subgroup species are unique among drosophilids in that they utilize an anal droplet-mediated pheromone communication system, some or all components of which are species specific. However, the lekking Hawaiian Drosophila species are similar to D. melanogaster and related continental species in that the Hawaiian flies employ a cuticular pheromone communication system, some components of which are sex and species-specific.     

Foraging vibration signals attract foragers and identify food size in the drywood termite, <Emphasis Type="Italic">Cryptotermes secundus</Emphasis>

Information gathering and communication behaviour has evolved within constraints of size, physiology and ecology of the animal. Due to these constraints, small herbivorous insects are likely to use substrate borne vibrations for information gathering and communication. Although such signals have been characterised in many types of insects, including group-living insects, they are poorly known in termites.We showed that the Australian drywood termite Cryptotermes secundus could determine the size of wooden blocks by using the vibrations generated during foraging. The termites behaved differently in choice experiments when artificially generated vibration signals were played compared with natural recordings, indicating that these termites can discriminate the source of the vibration as well. AT-maze experiment showed that the termites were attracted to the natural recordings of feeding termites, suggesting that vibrations are important in communication during foraging as well as food resource assessment. Combining the effects of food size preference and attraction to other termites explained differences in behaviour between artificially generated vibration signals compared with natural recordings. This study demonstrates that termites use substrate borne vibrations for information gathering and communication as predicted. Received 21 March 2007; revised 19 June and 7 August 2007; accepted 20 August 2007.     

Interactions with Combined Chemical Cues Inform Harvester Ant Foragers' Decisions to Leave the Nest in Search of Food

Social insect colonies operate without central control or any global assessment of what needs to be done by workers. Colony organization arises from the responses of individuals to local cues. Red harvester ants (Pogonomyrmex barbatus) regulate foraging using interactions between returning and outgoing foragers. The rate at which foragers return with seeds, a measure of food availability, sets the rate at which outgoing foragers leave the nest on foraging trips. We used mimics to test whether outgoing foragers inside the nest respond to the odor of food, oleic acid, the odor of the forager itself, cuticular hydrocarbons, or a combination of both with increased foraging activity. We compared foraging activity, the rate at which foragers passed a line on a trail, before and after the addition of mimics. The combination of both odors, those of food and of foragers, is required to stimulate foraging. The addition of blank mimics, mimics coated with food odor alone, or mimics coated with forager odor alone did not increase foraging activity. We compared the rates at which foragers inside the nest interacted with other ants, blank mimics, and mimics coated with a combination of food and forager odor. Foragers inside the nest interacted more with mimics coated with combined forager/seed odors than with blank mimics, and these interactions had the same effect as those with other foragers. Outgoing foragers inside the nest entrance are stimulated to leave the nest in search of food by interacting with foragers returning with seeds. By using the combined odors of forager cuticular hydrocarbons and of seeds, the colony captures precise information, on the timescale of seconds, about the current availability of food.     

Nest-mate recognition in Manuelia postica (Apidae: Xylocopinae): an eusocial trait is present in a solitary bee

In eusocial Hymenoptera, females are more tolerant towards nest-mate than towards non-nest-mate females. In solitary Hymenoptera, females are generally aggressive towards any conspecific female. Field observations of the nest biology of Manuelia postica suggested nest-mate recognition. Experiments were performed involving two live interacting females or one live female interacting with a dead female. Live females from different nests were more intolerant to each other than females from the same nest. Females were more intolerant towards non-nest-mate than towards nest-mate dead females. When dead females were washed with pentane, no differences in tolerant and intolerant behaviours were detected between non-nest-mate and nest-mate females. Females were more intolerant towards nest-mate female carcasses coated with the cuticular extract from a non-nest-mate than towards non-nest-mate female carcasses coated with the cuticular extract from a nest-mate. The compositions of the cuticular extracts was more similar between females from the same nest than between females from different nests. The results demonstrate for the first time nest-mate recognition mediated by cuticular chemicals in a largely solitary species of Apidae. The position of Manuelia at the base of the Apidae phylogeny suggests that nest-mate recognition in eusocial species apical to Manuelia represents the retention of a primitive capacity in Apidae.     

Peripheral, central and behavioral responses to the cuticular pheromone bouquet in Drosophila melanogaster males

Pheromonal communication is crucial with regard to mate choice in many animals including insects. Drosophila melanogaster flies produce a pheromonal bouquet with many cuticular hydrocarbons some of which diverge between the sexes and differently affect male courtship behavior. Cuticular pheromones have a relatively high weight and are thought to be -- mostly but not only -- detected by gustatory contact. However, the response of the peripheral and central gustatory systems to these substances remains poorly explored. We measured the effect induced by pheromonal cuticular mixtures on (i) the electrophysiological response of peripheral gustatory receptor neurons, (ii) the calcium variation in brain centers receiving these gustatory inputs and (iii) the behavioral reaction induced in control males and in mutant desat1 males, which show abnormal pheromone production and perception. While male and female pheromones induced inhibitory-like effects on taste receptor neurons, the contact of male pheromones on male fore-tarsi elicits a long-lasting response of higher intensity in the dedicated gustatory brain center. We found that the behavior of control males was more strongly inhibited by male pheromones than by female pheromones, but this difference disappeared in anosmic males. Mutant desat1 males showed an increased sensitivity of their peripheral gustatory neurons to contact pheromones and a behavioral incapacity to discriminate sex pheromones. Together our data indicate that cuticular hydrocarbons induce long-lasting inhibitory effects on the relevant taste pathway which may interact with the olfactory pathway to modulate pheromonal perception.