棉铃虫天敌中红侧沟茧蜂Microplitis mediator对不同处理棉花的趋性行为反应

采用机械损伤(处理A)、棉铃虫取食为害(处理B)、棉铃虫取食棉花 棉铃虫复合物(处理B H)、水杨酸诱导(处理C)、机械损伤加棉铃虫口腔分泌物(处理D)5种方式诱导现蕾期棉花植株,并应用Y型嗅觉仪测定处理后棉花对棉铃虫天敌中红侧沟茧蜂搜索寄主行为的影响.处理B、处理B H和处理C棉花对中红侧沟茧蜂有显著的引诱作用.健康棉株、处理A及处理D棉花对中红侧沟茧蜂没有明显的吸引.中红侧沟茧蜂对处理C、处理B H以及处理B棉花没有明显的趋性差异.利用气质联用系统对各处理棉花挥发性物质进行定性和定量分析.表明处理B、处理B H、处理C棉花挥发物种类和含量均比对照棉花多,处理A及处理D棉花与对照棉花挥发物种类和含量差异不显著.处理C、处理B及处理B H棉花中β-月桂烯、β-蒎烯、α-蒎烯的含量明显增加.处理C棉花柠檬烯的含量发生明显变化.图2表1参19     

一套寄生蜂和寄主相互关系实验模型的建立

通过显微手术建立一套研究寄生蜂和寄主关系的实验模型,以寄主体重为指标,用该模型研究了来自寄生蜂的活性物质（多态ＤＮＡ病毒（ＰＤＶ）,蜂毒,畸形细胞）和幼蜂本身对寄主生长发育的影响．结果表明,ＰＤＶ和蜂毒能够延迟寄主的生长,使之体色变淡,不能化蛹,但不足以模拟寄生现象;两者加上畸形细胞,可以显著抑制寄主的生长发育,使寄主表现出同被寄生一样的发育模式,最终因不能化蛹而衰竭死亡．这一结果说明,该模型能够有效地用于寄生蜂和寄主关系的研究中     

几株光合细菌的表型特征及DNA－NDA同源性分析

对５株新分离的光合细菌从形态、生理生化及ＤＮＡ－ＤＮＡ同源性等方面进行了研究．结果表明，菌株８与深红红螺菌（Ｐｈｏｄｏｓｐｉｒｉｌｌｕｍｒｕｂｒｕｍ）的模式菌株ＡＴＣＣ１１１７０的ＤＮＡ－ＤＮＡ同源性为９７％，菌株３７与沼泽红假单胞菌（Ｒｈｏｄｏｐｓｅｕｄｏｍｏｎａｓｐａｌｕｓｔｒｉｓ）的模式菌株ＡＴＣＣ１７００１的ＤＮＡ－ＤＮＡ同源性为８０％；菌株５５与球形红杆菌（Ｒｈｏｄｏｂａｃｔｅｒｓｐｈａｅｒｏｉｄｅｓ）的模式菌株ＡＴＣＣ１７０２３的ＤＮＡ－ＤＮＡ同源性为７１％；菌株４０和５２分别为另外两个ＤＮＡ同源群．根据各菌株形态、生理生化等表型特征以及ＤＮＡＧ＋Ｃｍｏｌ％和ＤＮＡ－ＤＮＡ同源性分析结果，确定了几株光合细菌的分类地位．     

基于食物链关系评价转Bt基因棉对寄生性天敌的非靶效应

按照“棉花 -棉大卷叶螟 (Syleptaderogata)幼虫 -螟蛉绒茧蜂 (Apantelesruficrus)”三级营养食物链关系 ,对田间转Bt基因棉苏抗 310对非靶物种螟蛉绒茧蜂种群的影响进行了调查。发现转Bt基因棉苏抗 310棉田间螟蛉绒茧蜂种群生长受到了不良影响 ,种群数量显著下降 ,棉大卷叶螟幼虫发生高峰期高龄幼虫被寄生率降低。     

基于食物链关系评价转Bt基因棉对寄生性天敌的非靶效应

按照“棉花—棉大卷叶螟(Sylepta derogata)幼虫—螟蛉绒茧蜂(Apanteles ruficrus)”三级营养食物链关系，对田间转Bt基因棉苏抗310对非靶物种螟蛉绒茧蜂种群的影响进行了调查。发现转Bt基因棉苏抗310稿田闻螟蛉绒茧蜂种群生长受到了不良影响，种群数量显著下降，棉大卷叶螟幼虫发生高峰期高龄幼虫被寄生率障队     

甲基紫精对植物细胞若干生理生化指标的影响

甲基紫精对植物细胞若干生理生化指标的影响曾庆平，刘叔文，郭勇（华南理工大学生物工程系广州５１０６４１）郑学勤（中国热带农业科学院热带作物生物技术国家重点实验室儋州５７１７３７）关键词甲基紫精；玫瑰茄（Ｈｉｂｉｓｃｕｓｓａｂｄａｒｉｆｆａ）；ＳＯＤ；诱...     

动物园中褐马鸡生理生化指标的研究

褐马鸡（Ｃｒｏｓｏｐｔｉｌｏｎｍａｎｔｃｈｕｒｉｃｕｎ）是我国一类保护动物,世界濒危物种．建立自然保护区和动物园饲养是保护濒危动物的有效措施．因此,了解在不同生态环境中褐马鸡生理生化指标的变化对它的饲养、繁殖和疾病防治及其保护都具有一定的实际意义．迄...     

黄精多糖对老龄大鼠衰老生理生化指标的影响

以水提法从黄精（Ｐｏｌｙｇｏｎａｔｕｍｓｐ）中得到的粗多糖成分（ＰＰ）进行了老龄大鼠的衰老生理生化指标测定试验．两种剂量的ＰＰ灌喂老龄大鼠１ｍｏ后，测定其１２项衰老生理生化指标：胸腺指数和脾脏指数，外周血淋巴细胞ＡＮＡＥ活性，红细胞、视网膜、晶体核、晶体皮质的ＳＯＤ活性，心脏、血浆中过氧化脂质含量，肝脏、肾脏中脂褐质含量及脑中Ｂ型单胺氧化酶活性．结果表明：除胸腺指数、血浆中过氧化脂质含量无显著性变化外，其他１０项指标均有明显的改善作用；试验结果经统计学处理有显著性差异．     

寄生曲霉产生絮凝剂的培养条件及其絮凝特性

从霉菌中筛选得到一株絮凝性较强的寄生曲霉（Ａｓｐｅｒｇｉｌｕｓｐａｒａｓｉｔｉｃｕｓ）．通过条件试验,确定寄生曲霉产生絮凝剂的最佳条件为：蔗糖作碳源,ＮａＮＯ３或脲或谷氨酸作氮源,初始ｐＨ为３．０,温度为２８℃,摇床的转速为１４０ｒ／ｍｉｎ．寄生曲霉在酸性条件下对高岭土具有很强的絮凝性,且有较高的热稳定性．     

黄地老虎NPV增效作用的研究

对黄地老虎核型多角体病毒（ＡｓＮＰＶ）的多角体蛋白和病毒粒子组分进行分离纯化,分别与棉铃虫核型多角体病毒（ＨａＮＰＶ）混合感染三龄棉铃虫幼虫,发现此二种组分均能够提高棉铃虫幼虫的死亡率,缩短半致死时间,降低半致死浓度。使用酶联免疫吸附测定（ＥＬＩＳＡ）技术检验ＡｓＮＰＶ多角体蛋白和病毒粒子与粘虫颗粒体病毒增效因子（ＰｓＧＶ－ＳＦ）和ＨａＮＰＶ多角体蛋白的同源性,发现ＡｓＮＰＶ多角体蛋白和病毒粒子与     

Cuckoo wasps manipulate foraging and resting activities in their hosts

Parasite-induced alterations in host behaviour have been reported in a large number of taxa. However, some parasites are better than others to exploit the resources offered by their hosts. To date, our understanding of the extent to which some obligate parasites exploit social insect colonies is still limited. In this study, we examined parasite-mediated behavioural alterations of Polistes biglumis wasps parasitized by the obligate social parasite Polistes atrimandibularis by comparing host female-activity in parasitized and non-parasitized colonies. Host foundresses foraged more and rested less in parasitized than in non-parasitized colonies (controlling for the number of larvae in the nest, the time of day, and the day in the season). Next, we used short-term parasite removal experiments to investigate how social parasites manipulate their hosts. We found that parasitized hosts foraged more and rested less when social parasites were on the nest rather than after their removal, and we tested which kind of interactions occurred between parasites and hosts. P. atrimandibularis parasites may use mainly non-aggressive interactions (such as antennation and trophallaxis) to manipulate host activities, rather than visual, acoustic or chemical signals as other parasites do.     

Intraspecific competition: the role of lags between attack and death in host-parasitoid interactions

Many natural enemies do not immediately kill their host, and the lag this creates between attack and host death results in mixed populations of uninfected and infected hosts. Both competition and parasitism are known to be major structuring forces in ecological communities; however, surprisingly little is known about how the competitive nature of infected hosts could affect the survival and dynamics of remaining uninfected host populations. Using a laboratory system comprising the Indian meal moth, Plodia interpunctella, and a solitary koinobiont parasitoid, Venturia canescens, we address this question by conducting replicated competition experiments between the unparasitized and parasitized classes of host larvae. For varying proportions of parasitized host larvae and competitor densities, we consider the effects of competition within (intraclass) and between (interclass) unparasitized and parasitized larvae on the survival, development time, and size of adult moths and parasitoid wasps. The greatest effects were on survival: increased competitor densities reduced survival of both parasitized and unparasitized larvae. However, unparasitized larvae survival, but not parasitized larvae survival, was reduced by increasing interclass competition. To our knowledge, this is the first experimental demonstration of the competitive superiority of parasitized over unparasitized hosts for limiting resources. We discuss possible mechanisms for this phenomenon, why it may have evolved, and its possible influence on the stability of host-parasite dynamics.     

Furanocoumarins and their detoxification in a tri-trophic interaction

The parsnip webworm, Depressaria pastinacella, specializes on wild parsnip, Pastinaca sativa, and several species of Heracleum, hostplants rich in toxic furanocoumarins. Rates of furanocoumarin metabolism in this species are among the highest known for any insect. Within its native range in Europe, webworms are heavily parasitized by the polyembryonic parasitoid wasp Copidosoma sosares. In this study, we determined whether these parasitoids are exposed to furanocoumarins in host hemolymph, whether they can metabolize furanocoumarins, and whether parasitism influences the ability of webworms to detoxify furanocoumarins. Hemolymph of webworms fed artificial diet containing 0.3 % fresh weight xanthotoxin, a furanocoumarin prevalent in wild parsnip hosts, contained trace amounts of this toxin; as well, hemolymph of webworms consuming P. sativa flowers and fruits contained trace amounts of six of seven furanocoumarins present in the hostplant. Thus, parasitoids likely encounter furanocoumarins in host hemolymph. Assays of xanthotoxin metabolism in C. sosares failed to show any ability to metabolize this compound. Parasitized webworms, collected from populations of Heracleum sphondylium in the Netherlands in 2004, were on average 55 % larger by weight than unparasitized individuals. This weight is inclusive of host and parasitoid masses. Absolute rates of detoxification (nmoles min⁻¹) of five different furanocoumarins were indistinguishable between parasitized and unparasitized ultimate instars, suggesting that the intrinsic rates of metabolism are fixed. Thus, although parasitized larvae are larger, detoxification rates are not commensurate with size; rates in parasitized larvae expressed per gram of larval mass were 25 % lower than in unparasitized larvae.     

Learning affects the preference for parasitized hosts of the facultative kleptoparasitoid <Emphasis Type="Italic">Eupelmus vuilleti</Emphasis>

For a facultative kleptoparasite, the decision to allocate time and energy to search for a prey or for a kleptoparasite opportunity could be influenced by its prior experience. In this study, we investigated the influence of experience on the proportion of the facultative kleptoparasitoid Eupelmus vuilleti females choosing an unparasitized host or a host parasitized by Dinarmus basalis. When exploiting hosts previously parasitized by D. basalis, a large proportion of E. vuilleti females reused the hole drilled by the D. basalis female, which led to a reduction in the time needed to reach the host. When submitted to successive choice tests between an unparasitized host and a host parasitized by D. basalis in a natural host-plant system, the proportion of E. vuilleti females which choose the parasitized host increased with the female experience. The same experiment carried out with an artificial host-plant system allowing an easy access to the host did not show a variation of the females’ choice with experience. A reward—here a faster access to the host through the hole drilled by the D. basalis female—seems necessary to mediate the associative learning expressed by the preferential choice of the parasitized host.     

The effects of parasitism on energy flow through laboratory shrimp populations

I quantified the effects of parasitism by the isopod Probopyrus pandalicola on energy flow through the host Palaemonetes pugio by comparing secondary production, metabolism, ingestion, and egestion by unparasitized laboratory shrimp populations to the same parameters for parasitized groups during 10 months. The effects of parasitism on host growth and metabolism vary from month to month. Temperature, season, host age, sex, and reproductive condition affect energetics for host-parasite systems. Probopyrus pandalicola has little effect on host assimilation efficiency. However, tissue growth efficiences during most study months were higher for control shrimp than parasitized shrimp. These differences between groups were of lesser magnitude when parasite production was considered in the calculations. Trophic level energy intake efficiency for parasites was of the order of 6 to 10% throughout much of the study—the highest values were calculated during the parasites' reproductive months. Through parasitic castration, P. pandalicola significantly affects host energetics. Significantly, parasite reproduction was often of the same magnitude as reproduction by unparasitized hosts, although parasite biomass accounts for only about 4% of the total host-parasite system biomass.     

Recognition of individual-specific marked parasitized hosts by the solitary parasitoid Epidinocarsis lopezi

Summary In parasitoid wasps, self-superparasitism (oviposition into a host already parasitized by the female herself) often contributes less to the reproductive success of the parasitoid than oviposition into a host previously parasitized by a conspecific (conspecific superparasitism). It could therefore often be profitable for parasitoids to avoid self-superparasitism. This requires a mechanism for either (1) the avoidance of previously searched areas and/or (2) the rejection of hosts containing eggs laid by the searching female. We investigated whether the solitary parasitoid Epidinocarsis lopezi is able to avoid self-superparasitism. We show that visits to previously searched patches were shorter than visits to unsearched patches and conclude that E. lopezi females leave a trail odour on patches they have searched. No differences were found between the time on patches previously searched by the wasp itself and on patches visited by conspecifics. However, E. lopezi superparasitizes fewer hosts previously parasitized by itself than hosts parasitized by a conspecific. Thus, they recognize an individual-specific mark in or on the host. We discuss how patch marking and host marking enable E. lopezi to avoid self-superparasitism.     

Tactics of parasitic American coots: host choice and the pattern of egg dispersion among host nests

Summary I examined the tactics adopted by a conspecific brood parasite, the American coot (Fulica americana), and the degree to which these tactics reflect sources of mortality for parasitic eggs. Only 8% of parasitic eggs produced independent offspring, compared to a 35% success rate for non-parasitic eggs, and most mortality was due to egg-rejection by hosts or the consequences of laying eggs too late in the host's nesting cycle. Parasites usually laid parasitically before initiating their own nests and usually parasitized immediate neighbours. Parasites did not remove host eggs before laying their own egg, and egg disappearance in general was not more common at parasitized nests. I found no evidence for non-random host choice, either on the basis of stage of the host's nesting cycle or the host's brood size. The absence of adaptive host choice is likely a consequence of the fact that, due to host limitation, only a small proportion of parasites had meaningful variation among potential hosts to choose from. The pattern of egg dispersion among host nests by individual parasites appears to be a compromise between constraints imposed by host limitation and the increased success obtained from spreading eggs among nests. Most females laying fewer than five parasitic eggs laid them in a single host nest while females laying five or more eggs normally parasitized two or more hosts. An examination of egg rejection and survival rates showed that parasites would maximize success by laying a single egg per host nest, and the pattern of laying several eggs per host nest is likely a consequence of host limitation. However, no egg that was the fifth laid, or later, parasitic egg in a host nest was ever successful and this probably explains why most females laying five or more eggs parasitized more than one host.     

Does supernormal stimulus influence parental behaviour of the cuckoo's host?

The supernormal stimulus hypothesis (SSH) states that a cuckoo chick should obtain more parental care than host young by means of exaggerated sensory signals. We tested the SSH by comparing parental care by reed warblers at parasitized and non-parasitized nests. A comparison of feeding rates to parasite and host chicks of the same size showed that parasitized nests received more food than non-parasitized ones with one host chick. There was an interesting relationship between average prey length and the mass of a cuckoo chick: prey length first increased with chick mass, but decreased after the cuckoo chick outgrew the average-sized host brood (three to four young at fledging). This might be expected if fosterers reduced the selectivity of their foraging behaviour when trying to satisfy the supernormal food demands of the parasitic chick. This suggestion is supported by the finding that the relationship between nestling mass and proportion of less economical small prey is inverse to the relationship between nestling mass and prey size. These results suggest that the parental behaviour of reed warblers is adjusted by selection to the needs of an average-sized brood. The overall proportion of insect orders was significantly different between the parasitic and host chicks. This result probably reflects the opportunistic foraging habits of the host. The qualitative difference (proportion of insect orders) between host and cuckoo nestling diets is partly a by-product of unequal length distribution of members of different taxonomic groups. The results of this study are consistent with the SSH.     

Almost royal: incomplete suppression of host worker ovarian development by a social parasite wasp

Insect social parasites, like other parasites, may benefit from inhibiting their host from reproducing (complete or partial parasitic castration) because they can then exploit more of the host’s resources for their own reproduction. In particular, social parasites that kill or expel the host queen need to prevent host workers from reproducing; this is a common worker response to the absence of their queen. Indeed, host workers would benefit from detecting the presence of the parasite and investing in direct and indirect fitness. Studying whether and how social parasites control host worker reproduction can provide information about the degree of integration of the parasite in the host colony and help identify factors regulating workers’ reproductive decisions in social insects. We investigated whether the paper wasp social parasite, Polistes sulcifer, suppresses Polistes dominula (host) worker reproduction as efficiently as the dominant host female does in queen-right colonies by comparing worker reproductive efforts in parasitized and non-parasitized (control) colonies. Our results show that 6 weeks after usurpation of their colony by the social parasite, parasitized workers (1) had more developed ovaries than control workers and (2) laid more eggs as soon as the opportunity arose. This reproductive readiness of parasitized workers was not apparent 2 weeks after colony usurpation. This suggests that P. dominula workers have evolved means to react to social parasitism, as occurs in some ants, and that the parasite has only limited control over host reproduction.