螟黄足盘绒茧蜂复合群支序系统学研究（膜翅目：茧蜂科：小腹茧蜂亚科）

对螟黄足盘绒茧蜂复合群Cotesia flavipes complex (膜翅目：茧蜂科：小腹茧蜂亚科)分布全世界的5个种和外群侧沟茧蜂Microplitis 及荻茧蜂Diolcogaster 的25个性状,以及复合群5个种和外群螟蛉盘绒茧蜂Cotesia ruficrus、粘虫盘绒茧蜂Cotesia kariyai、粉蝶盘绒茧蜂Cotesia glomerata 的24个性状,分别进行比较研究,并运用支序分析的方法探讨该复合群内5个种种间的系统发育关系。支序分析表明螟黄足盘绒茧蜂复合群是一单系群,二化螟盘绒茧蜂C. chilonis 和大螟盘绒茧蜂C. sesamiae 近缘,芦螟盘绒茧蜂C. chiloluteelli 和汉寿盘绒茧蜂C. hanshouensis 近缘,螟黄足盘绒茧蜂C. flavipes相对独立。 以上研究表明无论是以近缘属作外群还是以同属其它种作外群,所得结果基本上都能反映螟黄足盘绒茧蜂复合群各种之间的分类地位。     

螟蛉盘绒茧蜂的过寄生行为及其对子代生长发育的影响

【目的】过寄生现象普遍存在于寄生蜂寄生过程中。本研究旨在探究螟蛉盘绒茧蜂Cotesia ruficrus的过寄生对子代发育的影响及影响过寄生行为的主要因素。【方法】室内研究了螟蛉盘绒茧蜂在其寄主稻纵卷叶螟Cnaphalocrocis medinalis3龄幼虫上过寄生行为的发生,不同产卵次数对寄主存活及子代蜂生长发育的影响,研究了不同接蜂时间和不同接蜂密度对过寄生发生的影响。【结果】螟蛉盘绒茧蜂存在过寄生行为,无论雌蜂有无产卵寄生经历,均能在被自身寄生过和同种不同个体寄生过的寄主内产卵。寄生蜂茧量随着被产卵次数的增加而增加,被产卵3~5次的寄主体内死亡的寄生蜂幼虫数随着增大。寄主在育出蜂前的死亡率随着被产卵寄生次数的增加而增加,被产卵5次时,寄主育出蜂前死亡率达50%。过寄生使螟蛉盘绒茧蜂子代蜂卵-蛹的历期延长,羽化率和雌雄性比下降,雌蜂体型随寄生次数的增加显著变小。过寄生率随着接蜂密度及接蜂时间的增加而增加。【结论】在寄主上产卵2次对螟蛉盘绒茧蜂子代发育是最适合的,产卵3次及以上为过寄生。过寄生使蜂子代发育适合度降低,不利于子代生长发育。在室内大量繁殖螟蛉盘绒茧蜂时,应减少接蜂密度和接蜂时间,从而减少过寄生的发生。     

扬州地区水稻二化螟寄生蜂种类及主要寄生蜂发生动态

本文报道了江苏扬州地区水稻二化螟Chilo suppressalis(Walker)寄生蜂主要有10种,即中华钝唇姬蜂Eriborus sinicus(Holmgren)、二化螟盘绒茧蜂Cotesia chilonis(Munakata)、稻螟小腹茧蜂Microgaster russata Haliday、螟甲腹茧蜂Chelonus munakatae Munakata、中华茧蜂Amyosoma chinensis(Szepligeti)、螟黄足盘绒茧蜂Cotesia flavipes(Cameron)、夹色姬蜂Auberteterus alternecoloratus(Cushman)、桑蟥聚瘤姬蜂Iseropus(Gregopimpla)kuwanae(Viereck)、螟蛉瘤姬蜂Itoplectis naranyae(Ashmead)以及二化螟盘绒茧蜂的重寄生蜂绒茧灿金小蜂Trichomalopsis apanteloctena(Crawford)。田间系统调查表明:扬州地区7-9月水稻二化螟寄生蜂的主要种类为二化螟盘绒茧蜂、中华钝唇姬蜂、螟甲腹茧蜂、稻螟小腹茧蜂、螟蛉瘤姬蜂、桑蟥聚瘤姬蜂,但这些寄生蜂对一代水稻二化螟幼虫的寄生率较低,对二代水稻二化螟幼虫的寄生率高。水稻二化螟越冬期的系统调查表明:扬州地区二化螟越冬幼虫的寄生蜂主要有3种,即二化螟盘绒茧蜂、中华钝唇姬蜂和稻螟小腹茧蜂,其中二化螟盘绒茧蜂和中华钝唇姬蜂是寄生水稻二化螟越冬幼虫的优势种。水稻二化螟越冬幼虫的寄生率调查表明,扬州地区水稻二化螟越冬幼虫的寄生率在不同年份间有一定的波动,但一般都在15%以上,有的甚至高达89.88%,因此寄生蜂对二化螟越冬幼虫具有很好的控制作用,能有效压低来年水稻二化螟的田间越冬基数。此外,3种寄生蜂出茧时间在1月和2月之间达到最长,分别达到19.79 d、17.26 d和27.00 d,该结果表明,在扬州地区这3种寄生蜂可能都存在滞育现象。     

水稻大螟越冬幼虫寄生蜂种类调查与主要寄生蜂越冬动态分析

大螟Sesamia inferens（Walker）是水稻上一种重要的钻蛀性害虫,其寄主范围广,近年来为害加重。由于长期以来对大螟的防治采取兼治策略,大螟已经对多种农药产生了抗性。因此,掌握水稻大螟生物防治资源有重要的应用意义。本研究报道了江苏扬州地区水稻大螟越冬幼虫体内仅有两种寄生蜂,分别是中华茧蜂Amyosoma chinensis和螟黄足盘绒茧蜂Cotesia flavipes,其中螟黄足盘绒茧蜂是优势种群。通过近三年的系统调查发现：在自然界中螟黄足盘绒茧蜂在大螟越冬幼虫体内的寄生率呈现动态变化,最高寄生率达33.33%,并且不同年份之间有差异。螟黄足盘绒茧蜂最短出茧时间仅为5.0 d,最长不超过14.0 d。除了12月份至次年1月份采集的螟黄足盘绒茧蜂外,其它时间点采集到的螟黄足盘绒茧蜂的羽化率高达75%以上。该研究结果为利用螟黄足盘绒茧蜂防治大螟提供了研究基础。     

稻螟蛉性引诱剂土法提取及应用初报

近几年来,由于农药的大量使用,害虫天敌被抑制,所以稻螟蛉危害有上升的趋势。如1973年、1975年对三熟田中早稻和早插双晚的危害加剧。鉴于稻螟蛉是几种绒茧蜂的良好寄主,为了抑制其危害又保护天敌,1975年7月,我们作了稻螟蛉性引诱剂的土法提取及应用试验,现将方法及效果整理如下:     

化学农药与二化螟盘绒茧蜂对控制二化螟的不相容

【目的】近年来,多个地区二化螟Chilo suppressalis(Walker)发生危害加重,对水稻生产造成新的重大威胁。由于水稻二化螟对常规防治药剂产生了抗药性,二化螟盘绒茧蜂Cotesia chilonis(Munakata)作为田间二化螟幼虫的优势寄生蜂,正逐渐引起大家关注。本论文通过研究室内繁殖的二化螟盘绒茧蜂对田间二化螟的防治效果,以探明室内繁殖的二化螟盘绒茧蜂的防控能力;同时研究多种环境友好型农药对田间二化螟的防治效果,并分析比较药剂防治对二化螟盘绒茧蜂寄生控制的影响。【方法】设置2个放蜂密度和7种不同药剂处理,通过全查法系统调查不同处理小区的枯心数、白穗数、枯孕穗数、残留活虫数等变化以分析比较防效。【结果】2个放蜂密度(125头蜂茧和250头蜂茧)处理下都可有效减少二化螟对水稻的为害;但2个放蜂密度之间无显著性差异。同时,放蜂密度高,寄生率就高。药剂实验结果发现溴氰虫酰胺悬浮剂防效最佳,氯虫苯甲酰胺悬浮剂和苏云金杆菌悬浮剂次之,杀虫双的防效最差。不同剂量的溴氰虫酰胺悬浮剂防治效果也有较大差异。此外,放蜂处理的小区二化螟盘绒茧蜂具有最高的寄生率,但无论那种农药处理都显著降低了二化螟被二化螟盘绒茧蜂寄生的寄生率。【结论】二化螟盘绒茧蜂在田间对水稻二化螟具有一定的防控能力,但放蜂密度和技术仍然需要进一步研究。同时,所试验的7种杀虫剂均显著降低了二化螟绒茧蜂的控害效能,与释放二化螟绒茧蜂不兼容。在水稻二化螟药剂防治时不仅要考虑防治效果和使用剂量,还应考虑对天敌以及生态环境的影响。因此,本实验的结果为后续建立以二化螟盘绒茧蜂为中心的二化螟绿色防控体系提供了理论和实践基础。     

水稻害虫寄生天敌初探

为了更好地保护和利用害虫的天敌,从1972年开始,我们对水稻三化螟、稻纵卷叶螟和稻苞虫的寄生性天敌进行了调查。三年来在大田共发现寄生性天敌昆虫共12种(寄生蜂10种,寄生蝇2种)。已知学名的五种:①寄生于三化螟幼虫的爪哇沟姬蜂Isotimajavensis;②寄生于三化螟幼虫的三化螟茧蜂Tropo-bracon schoenobii;③寄生于三化螟卵的等腹黑卵蜂Telenomus dignus;④寄生于稻纵卷叶螟幼虫的螟蛉绒茧蜂Apanteles ruficrus;⑤寄生于稻纵卷叶螟幼虫和蛹的广大腿蜂 Brachymeria obscurata。     

菜蛾盘绒茧蜂卵携带的免疫抑制因子

抑制寄主昆虫的免疫反应是内寄生蜂存活的关键。菜蛾盘绒茧蜂Cotesia vestalis（Haliday）寄生小菜蛾Plutella xylostella （L.）幼虫后,蜂卵如何逃避和抑制寄主的免疫攻击,尚未得到全面揭示。本文采用电镜技术系统观察了菜蛾盘绒茧蜂卵表面的超微结构。结果显示：蜂卵表面覆盖有纤维层和絮状的类病毒样纤丝（VLFs）,同时携带了含多分DNA病毒粒子（PDV）的萼液。在寄生初期,包裹在蜂卵表面的纤维层和VLFs首先起到保护蜂卵不被小菜蛾血细胞包囊的被动防御作用。随后,PDV发挥主动的免疫抑制作用。通过假寄生手段,证明了菜蛾盘绒茧蜂PDV (CvBV) 具有较持久的克服寄主免疫攻击的能力,是主要的免疫抑制因子。在假寄生后连续8 d的观察时间内,菜蛾盘绒茧蜂的蜂卵均未被包囊。结果提示,在菜蛾盘绒茧蜂-小菜蛾寄生体系中,菜蛾盘绒茧蜂采取被动防御和主动攻击两种方式应对寄主小菜蛾的免疫攻击。     

亚致死剂量阿维菌素和氟虫睛处理小菜蛾对寄生蜂菜蛾绒茧蜂生长发育的影响

分别在小菜蛾体内的菜蛾绒茧蜂处于卵期、早期幼虫和中期幼虫时,饲喂小菜蛾2龄幼虫亚致死剂量（＝LC₁₀）的阿维菌素和氟虫睛,研究上述杀虫剂处理对寄主体内菜蛾绒茧蜂结茧率和羽化率的影响。结果表明： 在菜蛾绒茧蜂处于卵期、早期幼虫和中期幼虫时,饲喂小菜蛾LC₁₀剂量阿维菌素处理的菜叶后,菜蛾绒茧蜂的结茧率分别下降26.6%,22.8%和5.8%,饲喂小菜蛾LC₁₀剂量氟虫睛处理的菜叶后,菜蛾绒茧蜂的结茧率分别下降76.9%,42.5%和18.5%。上述阿维菌素处理对菜蛾绒茧蜂成虫羽化率影响不显著,但上述氟虫睛处理可显著抑制菜蛾绒茧蜂成虫羽化率,在菜蛾绒茧蜂处于卵期、早期幼虫和中期幼虫时,饲喂小菜蛾LC₁₀ 剂量氟虫睛处理的菜叶可导致菜蛾绒茧蜂成虫羽化率分别下降53.1%,36.1%和47.8%。结果显示,即便是对寄主小菜蛾幼虫很低的剂量（LC₁₀剂量）也会显著危害小菜蛾幼虫体内的菜蛾绒茧蜂的生长发育。此外,饲喂小菜蛾幼虫亚致死剂量杀虫剂对菜蛾绒茧蜂生长发育的影响与杀虫剂种类及蛾绒茧蜂发育阶段有关。     

秋末苏南茶园昆虫的群落组成及其趋色性

苏南地区名茶荟萃,而虫害历来较为严重。秋末选丹阳市一片无公害茶园,使用纯白、桃红、墨绿、果绿、湖蓝、天蓝、素馨黄、芽绿、土黄、桔黄、大红和紫色12种粘性色板诱虫。结果表明:① 4日内捕获7目42科85种30455头昆虫,其中优势类群是同翅目、膜翅目和双翅目,三者个体数分别占总个体数的86.5%、8.8%和2.5%。②主要害虫是假眼小绿叶蝉和茶蚜,分别占总个体数的15%和71.5%。③ 捕获的中华蜜蜂占总个体数8.2%。④捕获天敌昆虫1034头,其中,瓢虫类32头,占3.1%,主要种类是异色瓢虫和黄斑盘瓢虫;草蛉类582头,占56.3%,包括中华草蛉、大草蛉和丽草蛉;伞裙追寄蝇和蚕饰腹寄蝇等5种寄生蝇类111头,占10.7%;门氏食蚜蝇和黑带食蚜蝇等7种食蚜蝇类110头,占10.6%;螟蛉瘤姬蜂和花胸姬蜂等5种姬蜂类、茶尺蠖绒茧蜂和单白绵绒茧蜂等7种茧蜂类个体数分别占3.9%和9.4%。⑤ 芽绿、素馨黄和桔黄色板显著地引诱假眼小绿叶蝉和茶蚜;芽绿、素馨黄色板显著地引诱姬蜂和茧蜂;芽绿、土黄和果绿色板明显地引诱草蛉类;果绿、天蓝和紫色色板引诱较多的蝇类和蚊类等双翅目昆虫;素馨黄引诱的各类昆虫种数最多;纯白板上各类昆虫的多样性指数最大,表明其对许多昆虫都有引诱效应。秋末时节查明即将越冬的害虫和天敌昆虫种类、数量和益害比、以及优势种害虫和优势种天敌数量,探明多种色彩引诱益、害虫的差异,对于有效实施无公害封园防治,以压低越冬基数有重要意义。     

Molecular differentiation of the microgastrine species commonly found in paddy fields from Southeast Asia,with additional data on their phylogeny （Hymenoptera：Braconidae）

Partial DNA sequences of three genes, that is, mitochondrial large ribosomal subunit (16S), nuclear large ribosomal subunit (28S D2) and mitochondrial NADH1 dehydrogenase (NADH1) gene, were sequenced from different microgas trine species(Braconidae: Microgastrinae) collected fresh from paddy fields. The DNA sequences were used to determine the extent of sequence variation among species in order to evaluate the specific status of each species. Cladistic analysis was also used to infer a phylogenetic relationship among these species. The results showed that sequence divergence among species of the same genus Cotesia was much lower than those among different genera, such as Cotesia, Exoryza and Apanteles; the sequence similarity of 16S rDNA and NADH 1 genes between Cotesia sp. and C. chilonis was higher than that between C. sp. and C. ruficrus.Phylogenetic analyses suggested that four species of Cotesia were always grouped in the same clade regardless of using different analysis methods; Cotesia sp. and C. chilonis are more closely related to each other than to C. ruficrus, different from previous morphological results. Additionally, sequence analyses indicated that NADH1 gene has more parsimony informative characters than 28S rDNA D2 and 16S rDNA at the species-level analysis,indicating that NADH1 gene might be a useful marker for species-level analysis.     

生态恢复状态下天敌对小菜蛾的自然控制作用

通过组建不同防治措施下的小菜蛾自然种群生命表,结果表明,化学防治区小菜蛾自然种群趋势指数为52.52;在生态恢复区,天敌因子对目标害虫的自然控制作用得到恢复和增强,连续4个世代的小菜蛾种群趋势指数分别为16.9、7.16、3.71和4.02,其种群数量的发展得到有效地抑制.影响小菜蛾春季第一、第二、第三及第四代种群数量的重要因子分别为绒茧蜂寄生、4龄幼虫的捕食及其它、赤眼蜂寄生和绒茧蜂寄生,其相应的排除作用控制指数分别为1.39、1.56、1.74和1.54.从天敌与小菜蛾种群相互作用的过程来看,前者对后者的控制作用表现出明显的时滞效应,其种群数量的发展需要一个累积过程.能否采取积极的田间保护、增强措施,将是充分发挥天敌控害潜能的关键因素之一.     

Effects of crop species richness on pest-natural enemy systems based on an experimental model system using a microlandscape

The relationship between crop richness and predator-prey interactions as they relate to pest-natural enemy systems is a very important topic in ecology and greatly affects biological control services. The effects of crop arrangement on predator-prey interactions have received much attention as the basis for pest population management. To explore the internal mechanisms and factors driving the relationship between crop richness and pest population management, we designed an experimental model system of a microlandscape that included 50 plots and five treatments. Each treatment had 10 repetitions in each year from 2007 to 2010. The results showed that the biomass of pests and their natural enemies increased with increasing crop biomass and decreased with decreasing crop biomass; however, the effects of plant biomass on the pest and natural enemy biomass were not significant. The relationship between adjacent trophic levels was significant (such as pests and their natural enemies or crops and pests), whereas non-adjacent trophic levels (crops and natural enemies) did not significantly interact with each other. The ratio of natural enemy/pest biomass was the highest in the areas of four crop species that had the best biological control service. Having either low or high crop species richness did not enhance the pest population management service and lead to loss of biological control. Although the resource concentration hypothesis was not well supported by our results, high crop species richness could suppress the pest population, indicating that crop species richness could enhance biological control services. These results could be applied in habitat management aimed at biological control, provide the theoretical basis for agricultural landscape design, and also suggest new methods for integrated pest management.     

Synergizing biological control: Scope for sterile insect technique,induced plant defences and cultural techniques to enhance natural enemy impact

When used alone, only a minority of biological control programs succeed in bringing the target pest population under sufficient control. Biological control is, therefore, usually employed with chemical, cultural, genetic or other methods in an integrated pest management (IPM) strategy. The interactions between different pest management methods, especially conventional pesticides and host plant resistance, is an area of growing research interest but relatively little consideration is given to novel combinations. This paper reviews the interactions between biological control and other forms of pest management, especially induced plant defences and the novel, non-toxic plant protection compounds that may boost these defences; and sterile insect technique. We also cover the cultural methods that offer scope to support synergies between the aforementioned methodological combinations. We conclude that despite the sometimes negative consequences of other pest management techniques for biological control efficacy, there is great scope for new strategies to be developed that exploit synergies between biological control and various other techniques. Ultimately, however, we propose that future use of biological control will involve integration at a greater conceptual scale such that this important form of pest management is promoted as one of a suite of ecosystem services that can be engineered into farming systems and wider landscapes.     

A review of sugarcane stem borers and their natural enemies in Asia and Indian Ocean Islands: an Australian perspective

This paper provides a review on lepidopteran stem borer pests of graminaceous crops in Asia and Indian Ocean Islands which have the potential to invade Australia. Information on the geographical distribution, host plants and potential of invading Australia is provided for 36 stem borer species. A literature review of all natural enemies of 18 key pest species is provided. A knowledge of possible biological control options is essential to determine which natural enemies are to be considered for introduction following an incursion. The Braconid, Cotesia flavipes Cameron (Hymenoptera: Braconidae), stands out as a promising candidate for introduction into Australia following a borer incursion. Studies are currently being conducted on a native Cotesia species in Australia, which may be able to parasitize larvae of exotic borers, therefore minimizing the need for other parasitoids introductions.     

Multiple Parasitism by Cotesia sesamiae and Cotesia flavipes (Hymenoptera: Braconidae) on Busseola fusca (Lepidoptera: Noctuidae)

Busseola fusca (Fuller) is one of the most important pest of cereals in sub-Saharan Africa. Cotesia sesamiae (Cameron) is the predominant parasitoid attacking B. fusca larvae in many parts of Africa. An exotic parasitoid, Cotesia flavipes Cameron, was introduced into Kenya in 1993 for the control of Chilo partellus (Swinhoe). Laboratory studies indicated that although C. flavipes would search for, and attack B. fusca , it was not able to complete its development in this host. The aim of the present study was to investigate the outcome of multiple parasitism of B. fusca by the two Cotesia species. The study showed that when both parasitoid species stung a B. fusca larva at the same time, both parasitoids emerged from more than half of the host larvae, C. flavipes alone emerged from 17%, and C. sesamiae alone emerged from 9%. When the larvae were parasitized by C. sesamiae first, and then 2 h later by C. flavipes , and vice versa, most of the progeny were C. flavipes . However, when B. fusca larvae were stung by C. sesamiae three days before oviposition by C. flavipes , significantly more C. sesamiae emerged from the larvae. When C. flavipes oviposited first, no larvae produced C. flavipes only. The interaction of parasitoids and the host immune system, and the implications of these results for the biological control of stem borers in East Africa are discussed.     

Invasion theory and biological control

Recent advances in the mathematical theory of invasion dynamics have much to offer to biological control. Here we synthesize several results concerning the spatiotemporal dynamics that occur when a biocontrol agent spreads into a population of an invading pest species. We outline conditions under which specialist and generalist predators can influence the density and rate of spatial spread of the pest, including the rather stringent conditions under which a specialist predator can successfully reverse a pest invasion. We next discuss the connections between long distance dispersal and invasive spread, emphasizing the different consequences of fast spreading pests and predators. Recent theory has considered the effects of population stage-structure on invasion dynamics, and we discuss how population demography affects the biological control of invading pests. Because low population densities generally characterize early stages of an invasion, we discuss the lessons invasion theory teaches concerning the detectability of invasions. Stochasticity and density-dependent dynamics are common features of many real invasions, influencing both the spatial character (e.g. patchiness) of pest invasions and the success of biocontrol agents. We conclude by outlining theoretical results delineating how stochastic effects and complex dynamics generated by density dependence can facilitate or impede biological pest control.     

A simple criterion for successful biological control on annual crops

Population dynamics of pest insect-natural enemy systems on annual crops is quite different from those seen in classic biological control programes. On an annual crop, for example, the persistence of populations of pest insects is forced to terminate when crops are harvested. Pest control on annual crops aims to suppress the maximum density of the pest below a certain level, and a low level equilibrium is not always the aim. It is important to determine the initial impact just after release of a natural enemy in order to determine the success of a biological control program. Therefore, effectiveness of natural enemies should be evaluated by prediction of such short-term population dynamics. This paper presents a new and simple analytical model for successful biological control on annual crops. A criterion of successful biological control is given as the ratio of the pest and natural enemy populations just when the pest begins to decrease. This ratio is derived from the intrinsic rates of natural increase of both populations and the daily total predation by natural enemies. Using this model, criteria on appropriate number and time of release of natural enemies are obtained. The practical applications of this model are discussed with respect to evaluating the success or failure of natural enemy releases in future biological control programs.