蝗虫微孢子虫病对东亚飞蝗聚集行为的影响

采用行为生测法和触角电位法研究了感染蝗虫微孢子虫病的东亚飞蝗对其聚集信息素粗提物的行为反应。在第3龄时部分蝗虫每头接种10^6个蝗虫微孢子虫,与健虫同一条件下饲养。用二氯甲烷从健康蝗虫的粪便、体表或卵囊中抽提聚集信息素,粗提物经纯化和浓缩后保存于冰柜中待用。结果表明,感病飞蝗对其信息素的感受能力下降,聚集行为反应减弱。行为生物测定发现,微孢子虫病对第4龄雌性蝗虫和第5龄蝗虫的聚集行为有明显的抑制作用,而对第4龄雄蝗的影响较小;总的看来,信息素粗提物对感病雄蝗和高龄蝗虫的作用分别高于对感病雌蝗和低龄蝗虫的作用。触角电位(EAG)测定表明,感染了微孢子虫病的东亚飞蝗蝗蝻和成虫,对其信息素粗提物的敏感性降低,且对不同来源的聚集信息素的电生理反应不同,其中对从雄性成熟蝗虫、第4龄蝗蝻及第5龄病虫的粪便中抽提制备的信息素粗提物、第4龄蝗蝻粪便挥发物、第4龄蝗蝻活虫体表挥发物的电生理反应显著下降;但对第5龄雌蝗和第5龄散居型蝗虫的粪便抽提物的电生理活性,病健虫无明显差异。此研究结果证明,施用微孢子虫治蝗时,微孢子虫对蝗虫的聚集行为有明显的影响,为微孢子虫的控害机理提供了新的证据。     

西藏飞蝗虫粪粗提物的成分分析及其活性测定

西藏飞蝗作为青藏高原独有的飞蝗亚种,近年来发生危害严重,对其聚集机制的研究是西藏飞蝗生态治理的基础.采用自制Y型嗅觉仪、气质联用(GC-MS)和触角电位反应(EAG)等方法对西藏飞蝗虫粪粗提物进行了活性测定和成分分析.结果表明:乙醇浸提法是提取西藏飞蝗虫粪粗提物的较好方法.西藏飞蝗虫粪粗提物活性随虫龄增加,并且群居型成虫虫粪粗提物的活性最强.散居型蝗虫对蝗蝻虫粪粗提物的趋向性高于同虫态群居型蝗虫对蝗蝻虫粪粗提物的趋向性.不同虫态的西藏飞蝗虫粪粗提物所含化合物种类及含量有所差别,部分化合物与东亚飞蝗聚集信息素成分相同.西藏飞蝗对人工合成化合物的电生理反应变化趋势可分为三类:2μL/mL浓度下触角电位反应值最高;不同虫态西藏飞蝗对同一化合物的电生理反应变化趋势不一致;随浓度增加电生理反应显著增加.     

控制昆虫行为的生态活性物质的研究方法(Ⅱ)——生物测定法

在生态活性物质收集、抽提、纯化、结构鉴定以及合成过程中,生物测定是不可缺少的手段。生物测定前,首先要观察生物体在感受到其它个体释放的物质时,出现怎样的行为。特别是在出现一些定型的行为时,就可根据定型的行为作指标不断地进行跟踪测定,就有可能找到具有特异性的生态活性物质。下面以性信息素为中心介绍其生物测定法。现在常用的生物测定法大致可分二类三种。一类是给予生态活性物质后,直接观察昆     

葫芦岛地区东亚飞蝗体内的汞含量及分布

通过调查葫芦岛地区东亚飞蝗（Locusta migratoria manilensis）体内的Hg浓度,研究了Hg在其不同器官中的含量与分布。结果表明：葫芦岛地区东亚飞蝗体内的Hg浓度较高,Hg含量范围为0．33～174．86ng·g^-1,平均值为36．44ng·g^-1;东亚飞蝗体内总Hg及不同器官中总汞浓度均与体长、体质量呈显著的负相关;东亚飞蝗不同器官中的总Hg浓度为翅膀〉头〉腹〉胸≈足;随着飞蝗体质量增加,飞蝗体内绝对Hg含量增大,但生物量稀释作用使飞蝗体内总Hg浓度降低。Hg主要累积在飞蝗的翅膀和头部。生物量稀释作用及将Hg累积到翅膀中可能是东亚飞蝗抵御Hg危害的重要机制。     

美洲大蠊粪便粗提物的聚集活性

用不同溶剂不同方法提取美洲大蠊Periplaneta americana(L.)粪便,测定美洲大蠊各虫态的诱集活性。结果表明,采用直接浸泡提取方法,丙酮、乙醇、正己烷和二氯甲烷4种粗提物对美洲大蠊各虫态都具有明显的诱集作用,其中乙醇和丙酮粗提物的引诱效果最好,正己烷次之,二氯甲烷最弱。4种溶剂粗提物对美洲大蠊雄成虫和高龄若虫聚集活性最强,对低龄若虫聚集活性最弱。用乙醇溶剂对粪便粗提,3种提取方法均对美洲大蠊有很强的诱集效果,其中索氏抽提诱集效果最弱,直接浸泡和超声波提取效果好,且差异不显著,但直接浸泡提取效果更好。     

普通大蓟马聚集信息素的分离和鉴定

【目的】普通大蓟马Megalurothrips usitatus是我国华南地区重要的豆科害虫,给我国豇豆种植产业带来巨大损失。开发利用基于聚集信息素的引诱剂是普通大蓟马的绿色防控措施之一,对于普通大蓟马生物防治具有重要意义。【方法】采用Y型嗅觉仪测定普通大蓟马雌雄成虫对其雌虫和雄虫气味源的嗅觉反应;用顶空固相微萃取法(head space solid-phase microextraction, HS-SPME)和溶液浸提法提取普通大蓟马雌雄成虫挥发物;应用气质联用仪(gas chromatography-mass spectrometry, GC-MS)对收集的气体挥发物和正己烷提取物进行活性成分分离鉴定;应用Y型嗅觉仪测定人工合成聚集信息素组分对雌雄成虫的引诱效果。【结果】行为学试验结果表明,普通大蓟马雄成虫气味源对其雌雄成虫均具有显著的引诱作用,而雌成虫气味源则没有。顶空固相微萃取法和溶液浸提法均可提取雄成虫挥发物主要组分,但顶空固相微萃取法获得的TIC图基线平稳,杂峰少,提取效果优于溶剂浸提法。GC-MS分析结果表明,普通大蓟马雄成虫挥发物中主要含有 1种化合物,为反式,反式-金合欢醇乙酸酯［(E,E)-farnesyl acetate］,该化合物在雌成虫挥发物中不存在。室内行为学实验结果表明,特定剂量的人工合成的(E,E)-farnesyl acetate对普通大蓟马雌雄成虫均具有显著的引诱作用。【结论】本研究证明了普通大蓟马雄成虫可以释放聚集信息素,并鉴定了其主要组分(E,E)-farnesyl acetate,为应用聚集信息素开展普通大蓟马的监测和诱杀提供了基础。     

丝氨酸蛋白酶抑制剂Serpin1对东亚飞蝗酶学免疫的影响

Serpins是东亚飞蝗Locusta migratoria manilensis体内具有免疫调节功能的一类丝氨酸蛋白酶抑制剂.前期研究发现Serpin1能够降低绿僵菌Metarhizium对蝗虫的杀虫效果,本研究旨在从酶学角度明确Serpin1蛋白抑制绿僵菌毒力的原因,进一步揭示Serpins的功能与作用机制.本实验采用饵剂饲喂的方法进一步明确Serpin1蛋白对绿僵菌侵染东亚飞蝗的抑制效果;测定绿僵菌侵染东亚飞蝗过程中,添加Serpin1蛋白对东亚飞蝗体内保护酶(超氧化物歧化酶SOD、过氧化物酶POD、酚氧化酶PO)、解毒酶(多功能氧化酶MFO、谷胱甘肽转移酶GSTs、乙酰胆碱酯酶AchE)共6种酶的影响,以明确Serpin1对东亚飞蝗酶学免疫的调节作用.结果表明,Serpin1能够显著降低绿僵菌对蝗虫的杀虫效果;将Serpin1与绿僵菌混合后处理东亚飞蝗,12 d后其死亡率为63.5％,显著低于绿僵菌单独处理(死亡率为80.6％).酶活测定结果显示,将绿僵菌IMI330189与Serpin1蛋白混合处理后,与绿僵菌处理组相比,东亚飞蝗体内保护酶SOD和PO的活力总体表现为上调,而POD的活力呈现降低的趋势;解毒酶MFO、GSTs的活性呈现升高趋势,AChE的活力呈现先升高后降低的趋势.上述结果表明,Serpin1蛋白能够增强东亚飞蝗体内解毒酶和保护酶的活性,提高东亚飞蝗的酶学免疫,增强对绿僵菌侵染的抵御能力,从而降低东亚飞蝗的死亡率.本研究为进一步揭示Serpins的功能提供了参考.     

川金丝猴粪尿中类固醇性激素抽提方法比较

本文旨在探讨川金丝猴粪尿中类固醇性激素的抽提方法, 实验比较了3 种尿液抽提溶剂和5 种粪便抽提方法的抽提回收率。结果显示, 以二氯甲烷为溶剂抽提雄猴尿液中的睾酮、雌猴尿液中的雌二醇和孕酮, 回收率分别为79.27%、73.39%和80.28%, 抽提效果较其它两种溶剂为好; 以乙醇加热法抽提雄猴粪便中的睾酮和雌二醇、雌猴粪便中的睾酮、雌二醇和孕酮, 回收率分别为1.33%、85.12%与67.41%、79.58%和77.71%, 抽提效果优于其它4 种方法,且该方法简便易于操作。实验表明, 以二氯甲烷和乙醇加热法分别抽提川金丝猴尿液和粪便中的类固醇性激素是较理想的抽提方法。     

激光照射对蝗虫诱变杀灭效应的初步研究

为初步研究激光对蝗虫的诱变杀灭效应,将中华剑角蝗成虫、东亚飞蝗成虫和东亚飞蝗幼虫按种群分为照射试验组和对照组,选择采用波长808nm、功率2W的半导体连续单管激光器进行照射试验。分别取距离激光二极管发光面1cm处和2cm处以时间15s、10s、5s和3s进行蝗虫头部眼睛部位和翅膀部位辐照,探索蝗虫不同身体部位对激光的敏感性,比较激光对不同种类和龄期蝗虫的杀灭效应,并对蝗虫的活性进行观察。结果显示:不同强度及辐照时间的激光照射后,蝗虫的活性均有所降低,且照射时间越长、功率密度越大,蝗虫活性下降越显著;随着照射后时间的延长,群体蝗虫的活性降到一个较低的水平;激光对东亚飞蝗的辐照杀灭效应优于中华剑角蝗;蝗蝻较成虫容易被激光灭杀;头部眼睛部位较翅膀部位对激光敏感。     

东亚飞蝗选择栖息高度影响因素的研究

为明确东亚飞蝗Locusta migratoria manilensis对植物群落的利用特征,采用自然生境中罩笼的方法,观察东亚飞蝗对栖息高度的选择行为,分析发生代数、种群密度、调查时间以及环境温湿度对东亚飞蝗栖息高度选择的影响。结果表明:东亚飞蝗夏蝗偏好栖息在0～20 cm,秋蝗偏好栖息在80 cm。在食物充足的条件下,当蝗蝻密度d≤20头/m~2时,东亚飞蝗偏好栖息在植株中上部,以80 cm的蝗虫数量比最大;种群密度d=100头/m~2,飞蝗偏好栖息在植株较低位置,以0～20 cm的蝗虫数量比最大。东亚飞蝗在日出之前和日落之后偏好栖息在植株中上部;在12∶00和16∶00这两个时间段偏好选择栖息在植株中下部。选择栖息在0～20、40～60和80 cm这3个高度的东亚飞蝗数量百分比与环境温度呈负相关,但是与环境湿度呈显著的正相关(P0.05)。这说明随着温度的降低或湿度的增加,飞蝗偏好栖息在这3个位置。     

Disruption of aggregation behaviour of oriental migratory locusts (Locusta migratoria manilensis) infected with Nosema locustae

Abstract:  The effect of Nosema locustae infection on the aggregation behaviour of the oriental migratory locust, Locusta migratoria manilensis , was studied using a two-choice arena olfactometer and electroantennography (EAG). Infected locusts had low antennal sensitivity and aggregation responses to faecal extracts and to locust body volatiles. Infected fifth instar nymphs had significantly lower aggregation index than the uninfected nymphs, although with fourth instars the effect on aggregation behaviour only occurred in infected females. With regard to antennal receptor sensitivity, infected adult locusts had significantly lower EAG amplitudes in response to extracts from faeces of the adult males. The effect was most pronounced in female locusts. In contrast, there was no significant difference in the EAG responses between the fifth instar male and female nymphs. Further analysis revealed that EAG responses of fifth instar nymphs and adults infected with N. locustae to the faecal extract and volatiles from fifth instar solitary-reared nymphs were not significantly affected. In contrast, infected nymphs and adults had remarkably low EAG amplitudes for the remaining stimuli.     

蝗虫化学信息物质研究进展

详述了蝗虫主要化学信息物质的种类、功能及主要成分等研究进展。蝗虫化学信息物质包括种内通讯的化学信息素和种间通讯的化学信息物质。其中种内通讯的化学信息素主要有群居信息素、成熟信息素、产卵信息素(含促产卵化学信息素和群集产卵化学信息素)、性信息素、聚集信息素等;种间通讯的化学信息物质主要介绍用于防卫的化学信息物质,包括卵分泌的信息物质、特定腺体分泌的信息物质、粪便挥发的信息物质、口腔分泌物和内部毒素等,对其天敌均有一定的防卫作用。化学通讯是蝗虫种内和种间通讯联系的普遍方式。     

Responses of olfactory receptor neurones to behaviourally important odours in gregarious and solitarious desert locust, Schistocerca gregaria

Abstract.Recordings from antennal olfactory receptor neurones in young adult Schistocerca gregaria Forskål (Orthoptera: Acrididae) showed that behaviourally important odours are detected by receptor neurones present in morphologically identifiable sensillum types. Both nymph- and adult-produced aggregation pheromones activate receptor neurones housed in sensilla basiconica. The receptor neurones in this sensillum type in solitary-reared locusts display a higher sensitivity to aggregation pheromones and to some other behaviourally relevant odours than the same type of neurones in gregarious locusts. Receptor neurones present in sensilla coeloconica respond to green leaf odours, organic acids, and nymphal odours but are inhibited by mature adult-produced aggregation pheromones. Receptor neurones housed in sensilla trichodea respond to a possible sex pheromone. No phase differences were found in the response of coeloconic- or trichoid-associated receptor neurones.     

Tissue localization of aggregation pheromones in the American cockroach, <Emphasis Type="Italic">Periplaneta americana</Emphasis> (Blattodea: Blattidae)

The American cockroach, Periplaneta americana, excretes feces containing aggregation pheromones to attract conspecific individuals. It is thought that these pheromones play an important role in establishing and maintaining colonies. However, despite previous extensive efforts, the aggregation pheromones of P. americana have not been isolated. It is also unclear whether the aggregation pheromones of P. americana are truly biosynthesized by the insect, as most previous experiments extracted chemicals from feces. Here, we investigate the tissue localization of aggregation agents in P. americana. To reduce the effects of diet-derived odorants, we developed a new diet for P. americana consisting of only agar and sugars, and tested the attractiveness of fecal extracts from animals reared on this new diet. Our results show that the aggregation agents of fecal extracts are insect-derived, and the extracts from the midgut evoke stronger behavioral responses than those from other parts of the alimentary tract. This suggests that the midgut may be the production site or the storage organ of the aggregation agents. Thus, our data will facilitate the future identification of the aggregation pheromones of P. americana.     

Central nervous processing of behaviourally relevant odours in solitary and gregarious fifth instar locusts, Schistocerca gregaria

Physiological and morphological characteristics of antennal lobe neurons of solitary and gregarious fifth-instar nymphs of the desert locust, Schistocerca gregaria, were studied using intracellular recording and staining techniques. Physiological characteristics of antennal lobe neurons of both locust phases responding to stage-dependent aggregation pheromones, egg-laying attractants, a putative sex pheromone and plant-associated volatiles are described. Antennal lobe neurons showed excitatory, inhibitory, combined excitatory and inhibitory and delayed responses. In addition, one neuron␣showing an initial inhibition followed by an excitation and inhibition response was found. Pheromone-specific-, plant-specific- and pheromone-plant-generalist neurons were found in both locust phases. Antennal lobe neurons displayed stage- and phase-dependent differences in the processing of aggregation pheromone component input. Nymphal antennal lobe neurons showed stage-dependent response characteristics highly correlated with the preferential behavioural attraction to the nymphal aggregation pheromone. Phase-dependent differences were found in the response spectra and the sensitivity of the same neuron types. Neurons of solitary locusts responded significantly more frequently to some of the tested components than neurons of gregarious locusts. Furthermore, antennal lobe neurons of solitary locusts showed a higher sensitivity to most of the tested compounds. Accepted: 4 July 1998     

Phase-independent responses to phase-specific aggregation pheromone in adult desert locusts, Schistocerca gregaria (Orthoptera: Acrididae)

Abstract. Volatiles from solitary-reared (solitarious) and crowd-reared (gregarious) adult male desert locusts, Schistocerca gregaria (Forskal) (Orthoptera: Acrididae), were quantitatively and qualitatively different.In particular, solitarious males did not emit phenylacetonitrile, a key component of the aggregation pheromone produced by gregarious adult males.In laboratory bioassays, solitarious and gregarious adults of both sexes responded similarly to the natural aggregation pheromone blend, the major pheromone component phenylacetonitrile, and a synthetic pheromone blend comprising benzaldehyde, guaiacol, phenylacetonitrile and phenol.EAG measurements showed significant differences in the responsiveness of adults of the two phases to the four synthetic components at high doses; however, the general response patterns were similar.These results suggest that the gregarious adult male aggregation pheromone may play a role in the arrestment and subsequent recruitment of solitarious individuals into gregarious or gregarizing groups during the early stages of a locust outbreak.     

Optimization of organic solvent in multiphase biocatalysis

The microbial epoxidation of propene and 1-butene was used to study some fundamental aspects of two-liquid-phase biocatalytic conversions. Introduction of a water-immiscible organic solvent phase in a free-cell suspension gave rise to a series of undesired phenomena, e.g., inactivation by the solvent, clotting of biomass, and aggregation of cells at the liquid-liquid interface. Immobilization of the cells in hydrophilic gels, e.g., calcium alginate, prevented direct cell-organic solvent contact and the related clotting and aggregation of biomass. However, the gel entrapment did not seem to provide additional protection against the organic solvent. The influence of various organic solvents on the retention of immobilized-cell activity was related to solvent properties like the polarity (as expressed by the Hildebrand solubility parameter) and the molecular size (as expressed by the molecular weight or molar volume). High activity retention was favored by a low polarity in combination with a high molecular weight. The solubility parameter also proved useful to describe the capacity of various organic solvents for oxygen and alkene oxides. This facilitated the optimization of the solvent polarity.     

红火蚁工蚁对跟踪信息素的触角电位和行为反应

【目的】测定红火蚁Solenopsis invicta Buren工蚁对其跟踪信息素的触角电位（EAG）及行为反应。【方法】解剖红火蚁工蚁的杜氏腺, 用正己烷溶剂提取其分泌的跟踪信息素进行气相色谱-质谱（GC-MS）分析, 并测定了红火蚁工蚁对杜氏腺提取物、 工蚁提取物和合成的法尼烯混合物的EAG和招募行为反应。【结果】通过与合成的法尼烯混合物的气相色谱（GC）保留时间和质谱图比对, 发现杜氏腺提取物的主要成分并不是Z, E-α-法尼烯。EAG测定结果表明, 红火蚁工蚁对杜氏腺提取物、 工蚁提取物及100 μg的法尼烯混合物均有较强的EAG反应, 其次为10 μg和1 μg的法尼烯混合物。在招募行为测定中, 杜氏腺提取物和工蚁提取物招募作用明显, 而10, 1, 0.1和0.01 μg法尼烯混合物的作用均不显著。【结论】Z, E-α-法尼烯不是红火蚁跟踪信息素的主要成分; 红火蚁工蚁对杜氏腺提取物、 工蚁提取物有较强的EAG反应和明显的招募行为反应。     

生姜不同有机溶剂提取物的GC-MS分析

用GC－MS方法从生姜的甲醇、乙酸乙酯和正己烷提取中分别鉴定了35、36和44个成分。 显示三种有机溶剂提取物主要成分均为萜类化合物,但萜类含量各不相同：总萜类及倍半萜类成分的含量随提取溶剂极性增大而增多,单萜类成分则随提取溶剂极性增大而减少;具抗氧化活性的不饱和倍半萜成分随提取溶剂性增大而增多,说明了生姜有机溶剂提取物的抗氧化活性随提取溶剂极性增大而增强的原因。     

Olfactory attraction to aggregation pheromone is mediated by disti-flagellum of antennal segments in Riptortus pedestris

Riptortus pedestris (Hemiptera: Alydidae) is a serious pest of soybean and sweet persimmon and uses male produced aggregation pheromone, (E)-2-hexenyl (Z)-3-hexenoate, (E)-2-hexenyl (E)-2-hexenoate, and tetradecyl isobutyrate to facilitate food location and recognition by conspecifics. Using electroantennogram (EAG) and greenhouse bioassay, we determined which antennal segment is involved in the detection of their aggregation pheromone. In the first EAG test using individual antennal segments, significant EAG responses to 1:1:1 mixture of the aggregation pheromone were observed only from the disti-flagellum segments of both male and female antennae at both pheromone doses tested (1 µg and 100 µg). In the following EAG tests using gradually removed antennal segment(s), EAG response was still maintained when the distal half of a disti-flagellum was surgically removed, while EAG response was lost when whole segment of disti-flagellum or other whole segments were gradually removed from intact antenna of both sexes. In greenhouse experiment, removing one or both segment(s) of disti-flagellum from male or female antennae resulted in significant reduction in their attraction to the aggregation pheromone. Together, these findings support that the disti-flagellum of R. pedestris houses olfactory neurons associated with attraction to their aggregation pheromone.