红圆蚧三种寄生蜂的相互竞争研究

本文研究了红圆蚧（Ａｏｎｉｄｉｅｌｌａａｕｒａｎｔｉｉ）三种寄生蜂：盾蚧长缨蚜小峰（Ｅｎｃａｒｓｉａｃｉｔｒｉｎａ,ＥＣ）、岭南蚜小蜂（Ａｐｈｙｔｉｓｌｉｎｇｎａｎｅｓｉｓ,ＡＬ）和印巴黄蚜小蜂（Ａｐｈｙｔｉｓｍｅｌｉｎｕｉｓ,ＡＭ）的相互竞争。结果表明,ＥＣ蜂寄生过的寄主对ＡＭ蜂和ＡＬ蜂没影响,ＡＭ蜂能辩认被ＡＬ蜂寄生过的寄主,反之亦然,幼虫竞争能力ＡＬ蜂最强,其次ＡＭ蜂,最差为ＥＣ蜂。不同的寄主龄期产生不同的竞争结果：当ＡＭ蜂和ＡＬ蜂竞争时,若只供给３龄寄主则ＡＬ蜂获胜,若供给只有２龄寄主则ＡＭ蜂获胜;而ＡＭ或ＡＬ蜂与ＥＣ竞争时。若大多数寄主为２龄则ＥＣ蜂获胜,若大多数寄主为３龄则ＡＭ或ＡＬ蜂获胜。     

红圆蚧的空间分布及其自然种群生命表

调查了红圆蚧在不同定居地（果、叶、枝条和树干）的密度分布。结果表明,红圆蚧密度在果和树干上较高,在枝条和叶片上较低。红圆蚧的生命表研究说明,红圆蚧以各种虫态越冬,但低温对其存活影响很大。越冬成蚧存活率仅有１８．３％,各世代累积存活率在０．５４％￣３．８％之间变化。     

三种寄生物与一种寄主的系统模型研究

建立了红圆蚧与３种寄生蜂,盾蚧长缨蚜小蜂、岭地蚜小蜂和印黄蚜小蜂相互作用的系统模型,按红圆 的面积大小分成３种,ｓ（０．５５ｍｍ＾２以上）,ｔ（０３９－０．５５ｍｍ＾２）、ｕ（０．３９ｍｍ＾２以下）,分析三维系统（２种寄生物与１种寄主）和四维系统３种寄生物与１种寄主）在不同红圆蚧大小分布（ｓ,ｔ,ｕ）条件下系统的动态变化,确定了寄生物相互排扩和边界条件,为红介的生物防治决防治决策提供理论指导。     

芦苇收割对宫苍仁蚧密度及其五种寄生蜂共寄生关系的影响

【目的】本文旨在揭示芦苇Phragmites australis(Cav.)Trin.ex Steudel收割对宫苍仁蚧Nipponaclerda biwakoensis Kuwana密度及其5种寄生蜂寄生率和共寄生关系的影响及作用机制。【方法】在上海九段沙湿地上沙的芦苇未收割区和收割区分别设置16个和20个样方,于2011年7月和9月进行重复采样,对未收割区和收割区的蚧虫密度、寄生蜂寄生率、共寄生关系和雌性比率分别进行比较分析。【结果】芦苇收割能够显著降低蚧虫密度(P<0.001);从7月到9月,寄生蜂总寄生率呈增高趋势,但7月芦苇未收割区和收割区间寄生蜂总寄生率差异不显著(P>0.05),而9月芦苇收割区寄生蜂总寄生率则显著高于未收割区(P<0.001);而寄生蜂总寄生率与蚧虫密度相关性并不显著。不同寄生蜂对芦苇收割的响应不同,且存在时间差异性。7月,Aprotocetus sp.的寄生率最高,且在收割区的寄生率显著高于未收割区(P<0.05),而其他寄生蜂寄生率均较低。9月,Aprotocetus sp.的寄生率呈下降趋势,而其余寄生蜂寄生率则呈升高趋势;而且除Encyrtidae sp.外,其他寄生蜂寄生率在未收割区和收割区间存在显著差异(P<0.001)。此外,芦苇收割还显著增加Boucekiella depressa与Astymachus japonicus的共寄生率(P<0.001),并显著减少B.depressa与Aprotocetus sp.的共寄生率(P<0.001)。除Aprotocetus sp.(P<0.05)外,芦苇收割对寄生蜂的雌性比率无显著影响。【结论】不同寄生蜂对芦苇收割的响应,不仅依赖于蚧虫密度,而且还与寄生蜂的扩散能力和竞争能力等生物学特性有关。因此,芦苇收割能通过多种途径影响寄生天敌和宫苍仁蚧的高营养级互作关系,需引起足够的重视。     

圆斑弯叶毛瓢虫对湿地松粉蚧捕食作用研究

在室内试验条件下,研究了圆斑弯叶毛瓢虫Nephus ryuguus(Kamiya)对湿地松粉蚧Oracella acuta(Lobdell)的捕食功能反应和干扰反应,结果表明瓢虫的捕食功能反应符合Holling-Ⅱ型模型,捕食量随猎物密度的增加而增大;1～4龄幼虫和成虫理论最大捕食量分别为13.63头/d、21.57头/d、55.07头/d、66.39头/d和93.40头/d;对猎物的寻找效应随自身密度的增大而下降.在猎物密度不变的情况下,捕食率随自身密度的增加而减少,成虫个体之间的干扰反应经检验,符合Hassell-Varley干扰反应模型.     

扶桑绵粉蚧寄生蜂优势种Aenasiusbam bawalei Hayat记述

记述扶桑绵粉蚧Phenacoccus solenopsis Tinsley寄生蜂1中国新记录种:Aenasius bambawalei Hayat,2009,分布于广东、海南省;提供了种的形态特征描述和特征图.     

辽宁蚧虫寄生蜂二新种（膜翅目：跳小蜂科）

报道采自辽宁阜新的蚧虫寄生蜂2新种：微小玛丽跳小蜂Mayridia parva,Wu et Xu,sp.n和短棒多丽跳小蜂Doliphoceras brachyclavae Wu et Xu,sp.n.。本文也是玛丽跳小蜂属Mayridia Mecet和多丽跳小蜂属Doliphoceras Mercet在我国分布的首次记录,标本夏放于激光大学农业与生物技术学院应用昆虫研究所。     

松突圆蚧(Hemiberlesia Pitysophila Takagi)寄生蜂Aphytis sp的寄生与摄食研究

本文观察了Aphytis sp.在25种密度组合下的寄生与摄食,表明Aphytis sp.的功能反应适合Ⅱ型曲线,摄食作用随寄生蜂密度的增加而加强,随寄主密度的增加而减弱。并建立了新的二元寄生模型,模拟效果较好。     

The involvement of acetylcholinesterase in resistance of the California red scale shape Aonidiella aurantii to organophosphorus pesticides

Laboratory toxicity bioassays using chlorpyrifos (Dursban) confirmed the notion that development of resistance is responsible for widespread failures to control the California red scale, Aonidiella aurantii (Mask.) by applying organophosphorus (OP) compounds in citrus groves in Israel. Higher Vmax values of acetylcholinesterase (AChE) activity (9–13 fold) were measured in resistant strains collected from the field as compared to a susceptible line. No differences were found with respect to Km values using acetylthiocholine iodide as a substrate, or degree of inhibition (expressed by IC₅₀ values) by the OP compounds chlorpyrifos-oxon and paraoxon and the carbamate pirimicarb. We suggest that resistance of the California red scale is caused by excess of AChE molecules able to bind and thus scavenge inhibitory OP compounds. This scavenging mechanism related to AChE may be similar in other insect species where elevated levels of detoxifying esterases were implicated in conferring OP resistance.     

Activity patterns and oviposition rates of Aphytis lingnanensis females,a parasitoid of California red scale Aonidiella aurantii: implications for successful biological control

1. Activity patterns of Aphytis lingnanensis Compere (Hymenoptera: Aphelinidae) females were determined. Females have a preovipositional period of 2–6.5 h and oviposit daily until they die. The average lifetime fecundity was 191 eggs (n = 10 females), with a maximum of 13 eggs per day, but usually far fewer. Females do not lay eggs at night as low light levels reduce the propensity to oviposit. 2. Aphytis lingnanensis females showed a repeatable pattern of activity during the course of the day, ovipositing actively during the first 1.5 h of their 7 h exposure to hosts. Thereafter, activity levels decreased sharply and females spent relatively long intervals resting. Activity occurred in fairly discrete bouts, with long periods of inactivity, ranging from 12 to 231 min between bouts. 3. Each day, females laid most eggs during their first bout of oviposition, with availability of mature eggs in the ovaries dictating the duration and intensity of ovipositional bouts. Once females completed a bout of oviposition in the laboratory, they moved away from the hosts even though many suitable hosts remained. They stood immobile, sheltering, until they matured more eggs. 4. These results suggest how general biological control models and dynamic state variable models of behaviour can be made more realistic. In particular, the behaviour of females does not remain constant over extended periods, particularly because of egg depletion, which suggests that the interaction between the ovipositional history of the individual and its physiological capabilities dictates the response of females to particular circumstances, and thus contributes to patterns of parasitism in the field. 5. It is predicted that A. lingnanensis females in the field are inactive at night and begin ovipositing when it becomes light enough in the morning. Egg depletion is likely if enough hosts are available, but should occur later in the day than was recorded in the laboratory. Egg-depleted females are likely to shelter while they mature more eggs, but may undertake interpatch movement.     

草间小黑蛛对茶蚜的捕食功能反应

在实验室条件下研究了草间小黑蛛(Erigonidium graminicolum)对茶蚜(Toxoptera aurantii)的捕食作用。草间小黑蛛对茶蚜的捕食功能反应属于HollingⅡ型。草间小黑蛛有较强的种内干扰反应,随着捕食者密度的增大,草间小黑蛛的捕食率相应降低。猎物密度和天敌密度相互干扰会降低草间小黑蛛的寻找效应,但对捕食量没有影响。     

Effect of three diaspididae prey species on development and fecundity of the ladybeetle Chilocorus bipustulatus in the laboratory

The purpose of this investigation was to determine the most suitable prey for the development and fecundity of the predatory coccinellid, Chilocorus bipustulatus (L.) on three different diaspidid species: Aspidiotus nerii Bouché, Aonidiella aurantii (Maskell), and Pseudaulacaspis pentagona (Targioni-Tozzetti). Life tables were constructed at constant 25°C and the developmental time, longevity, fecundity, and the sex ratio were determined. Individuals fed with A. nerii displayed the shortest larval and pupal developmental time (26.0 days), lowest immature mortality rate (16.6%), highest net reproduction rate (264.7 females/ female), shortest generation time (72.9 days), and the highest intrinsic rate of increase (0.077 females/female/day). The results showed that under laboratory conditions C. bipustulatus developed best on A. nerii.     

Molecular relationships between populations of South African citrus thrips (Scirtothrips aurantii Faure) in South Africa and Queensland, Australia

Abstract   In response to the recent establishment of a population of South African citrus thrips ( Scirtothrips aurantii Faure) in Australia, we used DNA sequence data to examine whether this population is distinct from populations in South Africa. Mitochondrial and internal transcribed spacer (ITS2) DNA from populations from different host plants in Australia and South Africa showed no clear separation between populations that was entirely congruent with host plant or country of origin. Analysis of the ITS2 data was confounded by the presence of multiple different copies of the spacer in some populations. Neither the presence or absence, nor the sequence of these copies was clearly diagnostic for any one population. These preliminary data suggest that the Australian population is not a distinct species or subspecies from the populations of S. aurantii on either citrus or Bryophyllum in South Africa.     

Parasitism capacity and searching efficiency of Diaeretiella rapae parasitizing Brevicoryne brassicae on susceptible and resistant canola cultivars

Different cultivars of aplant species can affect the foraging and efficiency of natural enemies, both directly through physical and biochemical properties or indirectly through the herbivore's diet. In this study, the parasitism capacity and functional response of Diaeretiella rapae McIntosh were determined on the cabbage aphid, Brevicoryne brassicae (L.) reared on susceptible (Opera) and resistant (Okapi) canola cultivars under laboratory conditions at 25?±?1?°C, 60?±?5% RH and a16:8?h L:D photoperiod. The parasitoid exhibited Type II and Type III functional responses on the resistant and susceptible cultivars, respectively. The estimated value of searching efficiency (a) was 0.1637?±?0.1095?h^?1 on the resistant cultivar whereas its value was dependent on host density on the susceptible cultivar. The handling times (T_h) on the susceptible and resistant canola cultivars were 0.108?±?0.040 and 0.320?±?0.048?h, respectively. The net parasitism rate (C₀) of the parasitoid wasp varied from 128.09 hosts per parasitoid lifetime on the susceptible to 71.01hosts on the resistant canola cultivar. The transformation rate from host population to parasitoid offspring (Qp) was equal to 1 on both cultivars (C₀?=?R₀). The finite parasitism rate (ω) on the susceptible cultivar (0.819 hosts per parasitoid per day) was significantly higher than that on the resistant one (0.578 hosts per parasitoid per day). In conclusion, canola cultivars affected the performance of D. rapae in controlled small-scale laboratory experiments and compared with the susceptible cultivar, the resistant one had anadverseeffect on the efficiency of the parasitoid.     

Some interactions of two hymenopterous parasites of the chaff scale

The development of single, as well as mixed, populations of Aphytis hispanicus and Prospaltella inquirenda, the two important parasites of the chaff scale, Parlatoria pergandii was studied in laboratory. After 24 months of rearing, neither parasite displaced the other, though P.inquirenda, after an initial lag, began to overtake A.hispanicus. The practical applications of these findings are discussed.     

Aggregation of parasitoids and density-independence of parasitism in field populations of the wasp Aphytis melinus and its host, the red scale Aonidiella aurantii

ABSTRACT.

• 1 Repeated counts were made of the number of adult Aphytis melinus (DeBach) wasps per fruit on Valencia oranges in an orchard over two successive periods. Resulting rates of parasitism per fruit were measured at the end of each period.
• 2 For both periods, corresponding to high and low mean numbers of adult parasites, there was a significant positive regresssion of adult wasps per fruit on the number of available hosts per fruit. However, there was a high level of variability about the regression, and the overall aggregative response appears to be weak.
• 3 For both periods, rates of parasitism per fruit were independent of host density per fruit and they showed a high level of variability at all densities. Similar patterns were found in another, commercial, orchard over a wide range of mean host densities.
• 4 There was no evidence for aggregation of parasites or density dependence of parasitism at a patch size corresponding to the whole tree.
• 5 Suggestions based on some host-parasitoid models, that aggregations of parasite attack in areas of high host density are necessary for effective biological control, are rejected. However, the model of Hassell (1982), incorporating aggregation of parasites and limitations on the effectiveness of the parasite, seems to fit the data quite well.