土壤步甲和隐翅虫的采集与田间调查取样技术

活动于土壤地表的捕食性甲虫——步甲与隐翅虫,种类丰富、种群密度高、在农田害虫控制和农业生态系统平衡维持中发挥着重要的作用,采集调查这两类昆虫的种类、数量和变化,特别是与所捕食害虫种群动态相关联的季节变化,对于害虫控制是极为重要的。根据作者多年经验,筛选两种有效的田间采集与取样方法——陷阱法和草堆诱集法,本文重点介绍它们的基本原理与使用情况、田间设置的技术关键与规范、操作流程等,并对它们的样地设置原则及注意事项进行了简要讨论,从而方便这两项技术的推广使用。     

捕食性瓢虫采集与调查取样技术

捕食性瓢虫是重要的害虫天敌类群之一,主要捕食蚜虫、介壳虫、粉虱、叶螨等,对这些害虫的种群数量起着重要的控制作用。本文详细描述和发展了捕食性瓢虫的采集方法以及针对不同生态系统中捕食性瓢虫的调查和取样技术,为更好的利用瓢虫防治害虫提供技术支撑。     

宁波地区斜纹夜蛾幼虫寄生蜂调查研究

2007—2008年的6～11月对宁波地区重要害虫斜纹夜蛾的寄生性天敌进行了调查,发现寄生蜂有18种,主要种类有：马尼拉陡胸茧蜂Snellenius manilae、侧沟茧蜂Microplitis sp、棉铃虫齿唇姬蜂Carnpoletis chlorideae和斑痣悬茧蜂Meteorus pulchricornis,并对主要寄生蜂与斜纹夜蛾幼虫的田间消长动态进行了系统观察。     

寄生蜂对寄主生长发育的调控

寄生蜂在产卵时,常将一些特殊因子注射进寄主体内,从而对寄主的生长发育产生一定的调控作用.本文综述这几年的研究进展,着重从寄生蜂与寄主发育同步性的调控、寄生蜂对寄主代谢的调控及寄生蜂对寄主激素的调控三个方面概述了寄生蜂对寄主生长发育的调控.     

粉虱寄生蜂种类的调查与鉴定

通过采集调查、室内饲养和鉴定,初步获得福建省部分地区粉虱寄生蜂２２种,隶属于蚜小蜂科Ａｐｈｅｌｉｎｉｄａｅ的恩蚜小蜂属Ｅｎｃａｒｓｉａ Ｆｏｅｒｓｔｅｒ（１９种）和桨角蚜小蜂属Ｅｒｅｔｍｏｃｅｒｕｓ Ｈａｌｄｅｍａｎ（２种）,以及广腹细蜂科Ｐｌａｔｙｇａｓｔｅｒｉｄａｅ的Ａｍｉｔｕｓ（１种）。     

美洲斑潜蝇幼虫寄生蜂两种

本文报道美洲斑潜蝇幼虫寄生蜂两种,分别为丽潜蝇姬小蜂Neochrysocharis formosa(Westwood)、横柄金色潜蝇姬小蜂Chrysocharis crassiscapus(Thomson),前者为当地美洲斑潜蝇寄生性天敌的优势种.     

寄生蜂取食寄主特性及其在害虫生物防治中的作用

许多寄生性天敌昆虫的雌虫不仅寄生寄主, 而且还能取食寄主。在卵育型（synovigenic）寄生蜂类群中, 取食寄主行为是较为普遍的现象。本文综合近20年相关研究进展, 从寄生蜂类群、取食类型、生态学意义及影响因子等方面对寄生蜂的取食寄主行为进行了归纳总结。寄生蜂通过取食不仅可以杀死寄主, 直接起到控制害虫种群数量的作用, 还能通过取食策略为卵的成熟和再生提供营养来源, 对延长雌虫的寿命也有一定的帮助。对取食寄主行为的了解可为筛选优势寄生性天敌种类、评估寄生蜂在害虫生物防治中的作用提供重要信息。     

荔枝蝽-寄生蜂系统数量变动模型与应用

研究荔枝蝽－寄生蜂系统的数量变动规律,得到一个差分－积分方程组及求解的递推公式,指出了公式中参数的确定方法。推导出荔枝蝽－寄生蜂系统长期演变的特性,用模型证明了人工放蜂防治荔枝蝽的优越性及滥用农药的不良后果,给出了人工放蜂的最佳次数,最佳时刻及合适的放蜂量的计算公式,导出的结论与实验结果相符。     

寄生蜂成虫在寄主搜索过程中的学习行为

综述了寄生蜂寄主搜索过程中的学习行为的概念、过程、适应性意义及影响因子。学习是寄生蜂的一种普遍特征,但学习基本上只发生在成虫期,其中联系性学习是一个主要特征。学习可产生启动和嗜好性学习二种效应,在寄生蜂搜索寄主的各个步骤中发挥重要作用,使其在复杂多变的生存环境中可高效地识别和利用各种有用信息,提高搜索效率。学习的潜力及效应可依寄生蜂和寄主的食性专化程度、寄主的发育阶段、寄生蜂自身的生理状态及环境中刺激的性质等因子而变化。对寄生蜂学习行为的了解有助于发展对其行为调控的技术,提高寄生蜂对害虫控制的效能。     

大豆田间节肢动物群落调查取样方法的比较研究

[目的]为明确不同取样方法对分析农田节肢动物群落结构特征的影响.[方法]以大豆田间节肢动物群落为对象,采用网捕(WB)、吸虫机(XC)、定点定株(DD)、黄盘(HP)诱集和陷阱杯(XJ)诱集5种取样方法进行大豆田间节肢动物群落调查,并通过比较不同取样方法所得样本进行节肢动物群落结构特征分析结果的差异性,明确不同取样方法的优劣与可替代性.[结果]WB法采集到的类群最多,且与XC法无显著差异,DD法采集到的类群最少.从采集各目的科数、物种数和个体数看,WB法和XC法可采集大多数昆虫,DD法采集缨翅目昆虫最多,HP法采集膜翅目、双翅目、鞘翅目、跳虫目和蜱螨目种类较多,XJ法采集直翅目、膜翅目、鞘翅目和跳虫目昆虫较多.群落结构特征分析结果显示,WB法和XC机法相似性为0.75,效果相当,而其它方法之间相似性均小于0.42,相互间差异较大.在农田节肢动物群落调查时,采用WB+DD、WB+HP、WB+XJ 2种方法组合与WB+XC+DD+HP+XJ 5种方法组合获得的取样相似度均大于0.75的群落特征指标,选用WB+DD+HP、WB+DD+XJ和WB+HP+XJ 3种含有WB的方法组合与WB+XC+DD+ HP+XJ 5种方法组合获得的取样相似度均大于0.85的群落特征指标.[结论]正确选择或组合不同取样法进行群落调查可在有效提高群落生态研究的质量的同时减少调查工作量,在实际研究工作中,可根据群落对象特点和所关心的主要群落生态指标对调查取样方法进行合理选择.     

Natural variation in learning rate and memory dynamics in parasitoid wasps: opportunities for converging ecology and neuroscience

Although the neural and genetic pathways underlying learning and memory formation seem strikingly similar among species of distant animal phyla, several more subtle inter- and intraspecific differences become evident from studies on model organisms. The true significance of such variation can only be understood when integrating this with information on the ecological relevance. Here, we argue that parasitoid wasps provide an excellent opportunity for multi-disciplinary studies that integrate ultimate and proximate approaches. These insects display interspecific variation in learning rate and memory dynamics that reflects natural variation in a daunting foraging task that largely determines their fitness: finding the inconspicuous hosts to which they will assign their offspring to develop. We review bioassays used for oviposition learning, the ecological factors that are considered to underlie the observed differences in learning rate and memory dynamics, and the opportunities for convergence of ecology and neuroscience that are offered by using parasitoid wasps as model species. We advocate that variation in learning and memory traits has evolved to suit an insect's lifestyle within its ecological niche.     

Fitness effects of sex ratio response to host quality and size in the parasitoid wasp Spalangia cameroni

The parasitoid wasp Spalangia cameroni oviposited a greaterproportion of daughters in stable fly pupae than in house flypupae, even when I controlled for stable flies being smallerthan house flies. Sex ratio manipulation in response to hostquality has been modeled as being adaptive through an effectof host quality on the size and hence offspring production ofdaughters. 5. cameronis response to host species may insteadbe adaptive through an effect on larval survivorship, the developmenttime of daughters, and the size of sons. There was greater survivalof daughters than sons on stable flies. Controlling for hostsize, I found that development time of daughters was about 2%less on stable flies than on house flies. The decrease in developmenttime corresponds to a 2% increase in fitness as estimated byr, the intrinsic rate of increase, and is equivalent to abouta 9% increase in offspring production. Sons were about 2% largerfrom house flies than stable flies, which may increase offspringproduction by up to 3%. Host species had no consistent effecton size of daughters or development time of sons. In additionto the response to host species, mothers oviposited a greaterproportion of daughters in larger stable fly hosts. Whetherthis behavior is adaptive is unclear. Although offspring werelarger when they developed on larger stable flies, the rateof increase was less for daughters dian for sons. Effects ofstable fly size on offspring development time were negligible.     

REVIEW: The evolution of polyembryony in parasitoid wasps

Polyembryony has evolved independently in four families of parasitoid wasps. We review three main hypotheses for the selective forces favouring this developmental mode in parasitoids: polyembryony (i) reduces the costs of egg limitation; (ii) reduces the genetic conflict among offspring; and (iii) allows offspring to adjust their numbers to the quality of the host. Using comparative data and verbal and mathematical arguments, we evaluate the relative importance of the different selective forces through different evolutionary stages and in the different groups of polyembryonic wasps. We conclude that reducing the cost of egg limitation is especially important when large broods are favoured. Reducing genetic conflict may be most important when broods are small, thus might have been important during, or immediately following, the initial transition from monoembryony to polyembryony. Empirical data provide little support for the brood‐size adjustment hypothesis, although it is likely to interact with other selective forces favouring polyembryony.     

Suitability of five mealybug species (Hemiptera,Pseudococcidae) as hosts for the solitary parasitoid Anagyrus sp. nr. pseudococci (Girault) (Hymenoptera: Encyrtidae)

Anagyrus sp. nr. pseudococci is an endoparasitoid which has been used as a biological control agent of mealybug pests. In this study, we compared the suitability of five mealybugs species with different phylogenetic relationships and geographical origins as hosts of this parasitoid. The selected mealybugs were: (1) a Mediterranean-native species, Planococcus ficus, sharing a long co-evolutionary history with the parasitoid; (2) three exotic species, the Afrotropical Planococcus citri, the Australasian Pseudococcus calceolariae and the Neotropical Pseudococcus viburni, with a recent history; and (3) the Neotropical Phenacoccus peruvianus, with no previous common history with the parasitoid. Host suitability was assessed based on different fitness parameters, such as body size, developmental time, emergence rate and sex ratio. The parasitoid was able to complete development in all mealybug species. Nevertheless, its emergence rate significantly varied among mealybug species, with the highest values observed in Pl. ficus and Pl. citri, intermediate values in Ps. calceolariae and the lowest ones in Ps. viburni and Ph. peruvianus. The body size of adult wasp females varied with host suitability and was positively correlated with other measures of parasitoid fitness, including the emergence rate and the sex ratio. The parasitoid developmental time differed among mealybug species but did not correlate with any other measure of fitness. A female biased sex ratio was found in the parasitoid progeny emerged from all mealybug species, except in Ps. viburni and Ph. peruvianus. There was a direct relationship between the proportion of females in the parasitoid progeny and the emergence rate.     

Comparative phylogeography across two trophic levels: the oak gall wasp Andricus kollari and its chalcid parasitoid Megastigmus stigmatizans

Insect parasitoids are important components of many terrestrial ecosystems. However, relatively little is known about the mechanisms responsible for structuring their populations. Here we investigate the ability of Megastigmus stigmatizans, an oak gall wasp parasitoid, to track its host Andricus kollari over two different timescales, and examine its current population structure across a divide in host population structure. The divide represents a transition in gall wasp host-plant species and offers the opportunity to examine whether the split, which divides gall wasp populations, manifests itself in the next trophic level. Analysis of mitochondrial haplotype data for parasitoid and host reveals: (i) A similar phylogeographic population structure for both, with Iberian populations more derived with respect to more eastern populations. (ii) It is likely that the host colonized the Iberian refuge earlier than the parasitoid, probably by at least one glacial cycle. (iii) Recent range expansion of central European host populations northwards has resulted in pursuit by parasitoids from the same geographic origin. (iv) In addition, Iberian parasitoid populations have crossed a major divide in host population structure to invade northern Europe. Such human-facilitated escape from natural refugial distributions may have important implications for the composition and structure of northern European gall wasp communities.     

Natural selection in the laboratory for a change in resistance byDrosophila melanogaster to the parasitoid waspAsobara tabida

The selection response of the polymorphic hostD. melanogaster (Meigen) to the braconid waspA. tabida (Nees) is addressed. Cages of flies with and without wasps were initiated with a population ofD. melanogaster that exhibited variation both in larval foraging behavior and in encapsulation ability. Encapsulation ability was measured as the proportion of parasitized larvae that produce a hardened capsule which encapsulates the wasp egg and ultimately kills the wasp larva. We determined whether the host population changed its encapsulation ability and/or its foraging behavior in response to the wasp. Both species were collected from a local orchard whereA. tabida is the only wasp known to parasitizeD. melanogaster larvae. The naturally occurring genetic polymorphism for rover and sitter larval foraging behavior inD. melanogaster is also found in this field population.A. tabida's vibrotactic search behavior enables it to detect rover more frequently than sitter larvae. Rover larvae move significantly more while feeding than do sitter larvae. In this field population, rover larvae also show higher encapsulation abilities than do sitter larvae. Six cage populations, three without wasps and three with wasps, each containing an equal mixture of rover and sitter flies, were established in the laboratory and maintained for 19 fly generations. Selection pressure in the laboratory was similar to that found in the field population from which the flies and wasps were derived. We found that larvae from cages with wasps developed a significantly higher frequency of encapsulation than those reared without wasps. We were, however, unable to detect a change in larval movement (rover or sitter behavior) in larvae from cages subject to selection from wasps compared to larvae from cages containing no wasps. This may have resulted from a balance between two selective forces, selection against rovers by the wasps' use of vibrotaxis, and selection for rovers resulting from their increased encapsulation abilities     

稻飞虱种群发生的调查与取样技术

稻飞虱是中国和许多国家水稻生产上的主要害虫,属r对策暴发危害类型。其中,褐飞虱和白背飞虱是典型的远距离迁飞性害虫,具有大区域同期"突增"和"突减"的灾变特性;灰飞虱则主要以本地越冬为主,远距离迁飞对种群结构的影响较小,但其传播的病毒病对水稻生产的影响更甚。针对3种稻飞虱的生物学特性,本文发展了稻飞虱田间种群发生与危害等的调查与取样技术,为其种群发生及其监测预警提供技术支撑。     

Molecular analysis of parasitoid linkages (MAPL): gut contents of adult parasitoid wasps reveal larval host

Metamorphosing insects often have complex and poorly known life histories. In particular, what they feed on during their larval stages remains unknown for the vast majority of species, and its documentation only results from difficult and time-intensive field observations, rearing or dissections. Through the application of a DNA analysis of gut contents in adult parasitoid wasps, we were able to selectively sequence a diagnostic DNA marker that permitted the identification of the host used by these wasps during their larval stages. By reproducing these results in species with different life histories, we excluded other potential sources of host DNA, confirming that after ingestion by the parasitoid larva the host DNA can persist through metamorphosis in the abdominal contents of the adult wasp. Our discovery considerably extends the applicability of molecular analysis of gut contents by enabling the documentation of food used by insects during their larval stages and thus increasing the accuracy and precision of food web studies. The 24% success rate of our approach is surprisingly high considering the challenging context for host DNA preservation, and we discuss the factors possibly affecting this rate. We propose molecular analysis of parasitoid linkages (MAPL) as a new method to document host-parasitoid associations at a faster pace and with unrivalled precision. Because of the key regulatory role of parasitoid wasps in ecosystems, which makes them the most commonly used biological control agents, MAPL will have immediate applications in both basic and applied biological sciences.     

Characteristics of pathogenic and mutualistic relationships of ascoviruses in field populations of parasitoid wasps

Ascoviruses are disseminated among larvae in lepidopteran populations by parasitic wasps during oviposition. Ascovirus relationships with these wasps vary from pathogenic to mutualistic, and experimentally can be shown possibly to be commensal non-pathogenic virus having little or no effect. Most ascoviruses are pathogens that female wasps vector mechanically. Other ascoviruses have a more intimate relationship with their wasp vectors in that their genome is stably maintained in all wasp nuclei through several generations by vertical transmission. In this relationship, these viruses are mutualistic, enhancing the successful development of the wasp larvae by suppressing lepidopteran defence mechanisms. The DpAV4 ascovirus is a mutualist in certain Diadromus wasps but is pathogenic or not when vectored by other species of this genus. These various biologies suggest that ascovirus/wasp relationships depend on wasp regulatory factors that control virus replication. Thus, certain ascoviruses can potentially have either a pathogenic, mutualistic, or non-pathogenic relationship with a specific wasp vector, the type of relationship being dependent upon the species system in which the relationship evolved. Finally, because ascoviruses appear to be related to ichnoviruses (Polydnaviridae), the DpAV4/Diadromus system constitutes a possible interesting intermediate between the pathogenic ascoviruses and symbiotic viruses that evolved to be ichnoviruses.