小黑瓢虫对高氏瘤粉虱捕食作用的研究

在高氏瘤粉虱不同虫态共存的条件下,小黑标虫对高氏瘤粉虱各虫态的选择次序为卵＞1龄若虫＞2龄若虫＞3龄若虫＞4龄若虫和拟蛹,对卵的捕食率均最高,有明显的嗜好选择;小黑瓢虫幼虫捕食粉虱卵的数量,随着龄期的增长而递增,其中4龄幼虫的捕食量最大,4龄期捕食量平均为1565．42粒,占全幼虫期总食卵量的45．42％,整个幼虫期可捕食高氏瘤粉虱的卵数平均为3446．5粒。小黑瓢虫3龄幼虫对粉虱卵的捕食作用率在所给的猎物密度（1500粒／皿）条件下,随着自身密度的增加而降低。     

小黑瓢虫形态特征及生物学特性观察

小黑瓢虫(Delphastus catalirtae(Horn))是粉虱害虫的重要捕食性天敌。本对小黑瓢虫从英国引种后的形态特征和生物学特性进行观察,用福州地区新的猎物寄主高氏瘤粉虱(Aleurotubercutatus takahashii David＆Subramaniam)进行饲养繁殖,已成功地在室内定殖和繁衍。小黑瓢虫成虫寿命长达90—130天．可捕食粉虱卵、若虫、成虫各虫态,且捕食量大,活动能力强,是高氏瘤粉虱的有效天敌,具有很好的保护利用价值。     

小黑瓢虫对甘薯粉虱的捕食选择性和种内干扰反应

‘小黑瓢虫Delphastus cataline(Hom)是我国1996年引进的粉虱重要捕食性天敌.引进后我们对其进行保种定殖,并研究了其对甘薯粉虱Bemisia tabaci的捕食选择性和种内干扰反应.     

国外害虫天敌产品的商品化及小黑瓢虫的引种利用

长期以来由于大量使用化学农药对环境造成严重污染,并对人、畜健康造成危害,已引起世界各国的普遍关注,本文介绍英国作物生物保护有限公司（Biological Crop Protection Limited,BCP公再)开发害虫天敌产品,开拓天敌产品市场,发展害虫生物防治技术的经验,并报道粉虱害虫的重要天敌小黑飘虫Delphastus pusillus(LeConte)的引种与利用。     

小黑瓢虫与两种猎物作用系统研究:选择捕食作用

研究了小黑瓢虫与烟粉虱及红蜘蛛两种猎物作用系统中 ,小黑瓢虫雌成虫对两种猎物卵的选择捕食作用。结果表明 :当两种猎物共存时 ,小黑瓢虫雌成虫对烟粉虱卵在低密度下不表现喜好性 ,而在中等密度和高密度下表现正喜好性 ,对红蜘蛛卵在各密度下均不表现喜好性。对烟粉虱卵的转换效应会由于总猎物密度的不同而呈现不同的效应 ,即在低密度 (15 0粒 )时无转换行为 ,在中等密度 (30 0粒 )时有负转换行为 ,在高密度 (6 0 0粒 )时有正转换行为。而对红蜘蛛卵则在各总猎物密度下均呈现负转换效应。同时组建了两种猎物共存时 ,小黑瓢虫雌成虫对猎物的总捕食作用方程及对每一种猎物类型的捕食作用方程 ,分析了两种猎物共存时 ,小黑瓢虫雌成虫对各猎物寻找效应的变化情况。     

小黑瓢虫新猎物--高氏瘤粉虱发育速率模型的研究

高氏瘤粉虱Aleurotuberculatus takahashi David et Subramaniam是小黑瓢虫Delphastus catalinae的新猎物寄主,本测定了不同温度下高氏瘤粉虱的发育速率,得出高氏瘤粉虱各虫态的发育起点温度为：卵期8.30℃、一龄若虫6.46℃、二龄若虫7.71℃、三龄若虫7.12℃、四龄若虫一拟蛹7.68℃、产卵前期7.90℃、世代7.64℃。另外还得出发育速率与温度关系的线性日度模型、Logistic模型。     

昆虫群落中天敌间的致死干扰竞争作用

致死干扰竞争作用(lethal interference competition)是近些年来才被人们认识到的更为复杂的种间竞争关系, 是昆虫天敌间竞争的一种极端形式, 广泛存在于寄生性天敌昆虫之间。本文从其定义、 作用机制、 方式及其与害虫生物防治的相互关系几个方面介绍了天敌群落中的这一典型的种间相互关系。根据作用机制的不同, 可将致死干扰竞争作用分为外竞争和内竞争; 其通常的作用方式包括多寄生(超寄生)、 复寄生、 杀卵作用、 寄主取食、 物理攻击和生理抑制等。深入全面地研究这一种间关系对于有效生防作用物的筛选和引入, 以及整个生防系统群落的稳定性具有重要意义。     

束管食螨瓢虫研究及利用概述

束管食螨瓢虫StethoruschengiSasaji隶属于鞘翅目、瓢虫科、小毛瓢虫亚科、食螨瓢虫属Stethorini,是多种作物叶螨的重要天敌。1968年Sasajif[1]在我国台湾采集到该天敌,并对其分类特征进行了描述,1975年庞雄飞等[2]首次报道了我国大陆的分布情况,发现其对豆类作物上的红叶螨有一定控制作用。西南农业大学植保系于80年代中期,着手调查了束管食螨瓢虫在四川的分布、生活习性以及田间消长规律,并考察其捕食行为、农药影响等,现将有关该天敌的研究情况总结如下。1分布迄今的文献表明,束管食螨瓢虫仅见分布在我国的陕西、湖北、江苏、…     

龟纹瓢虫成虫对麦蚜捕食作用的研究

通过田间调查与室内观察表明,龟纹瓢虫对麦蚜的追随关系紧密,其对麦蚜的功能反应属Holling的Ⅱ型反应。捕食若蚜的圆盘方程为Na=0.9929N/1+0.0127N,捕食成蚜的圆盘方程为Na=1.2243N/1+0.0571N,一昼夜对若蚜和成蚜的捕食量上限分别为78头和22头。     

昆虫种间表观竞争研究进展

表观竞争是资源竞争以外的一种新型的种间关系,是指由共同享有的自然天敌中介的、物种之间在种群数量上表现出明显负效应的现象。物种之间的表观竞争被认为和资源竞争具有同等的重要性,尤其是对植食性昆虫来说更为重要。近十年来关于昆虫表观竞争的理论和实验研究进展迅速,已成为昆虫生态学研究中的一个新的生长点。本文从表观竞争的定义、实验研究实例、理论模型、作用机制及共存机制等方面,对近些年来关于昆虫表观竞争研究的进展进行了概括和总结,并对表观竞争理论在害虫防治中的应用前景进行了展望。     

湿度对小黑瓢虫生长发育及存活的影响

本研究了不同湿度条件下小黑瓢虫各虫态的发育历期及存活率,结果表明：（1）小黑瓢虫各虫态及世代历期均表现出低湿长于高湿,世代历期在85％RH下最短,但与75％RH相差不大;（2）卵期的存活率除在95％RH下较低（0．850）外,其余各湿度下均高于0．950,各虫态历期中,低湿与高湿均不利于其存活,在一定的范围内,随着相对湿度的升高,存活率逐渐增大,在85％RH下存活率了大值,而后呈下降趋势;（3）组建了小黑瓢虫各虫态发育历期与湿度及存活率与湿度的二次三项回归方程,经卡方检验,均达显水平,说明各方程式成立。     

替代猎物红蜘蛛Tetranychus nr. fijiensis对小黑瓢虫实验种群的影响

本文在实验室条件下,以自然猎物烟粉虱Bemisia tabaci为对照,研究了替代猎物红蜘蛛Tetrany-chus nr．fijiensis对小黑瓢虫的发育、存活、繁殖及实验种群增长的综合影响,结果表明：小黑瓢虫以红蜘蛛为猎物时,成虫可产卵并可完成整个世代。与自然猎物烟粉虱相比,小黑瓢虫取食替代猎物红蜘蛛时,各虫态及世代历期延长,世代死亡率提高,产卵前期延长,总产卵量及平均每雌日产卵量减少,而两者之间的性比、产卵率、产卵期及雌虫寿命无显著差异。2种猎物条件下的种群增长指数和内禀增长率分别为8．85、0．0658(红蜘蛛)和55．38、0．1905(烟粉虱)。     

Effects of toxins from two strains of Verticillium lecanii (Hyphomycetes) on bioattributes of a predatory ladybeetle, Delphastus catalinae (Col., Coccinellidae)

Abstract:  The aim of this study was to test the hypothesis that the whitefly ( Bemisia tabaci ; Hom., Aleyrodidae) predator ladybird beetles, Delphastus catalinae (Col., Coccinellidae), are not adversely affected in the field by the crude insecticidal toxins extracted from two strains of the fungus Verticillium lecanii , V3450 and Vp28. We developed a method to evaluate sublethal toxicity and its effects on consumption and functional response of D. catalinae . The crude toxins have low toxicity against beetle larva with LC₅₀ values of 1942 (1393–2710) and 2471 (1291–4731) p.p.m., respectively (approximately 10- and 12-fold of field rate of application 200 p.p.m.). The adult beetles had less sensitivity to crude toxins with LC₅₀ values of 4260 (3376–5375) and 4426 (1734–11298) p.p.m., respectively (approximately 20- and 22-fold of field rate 200 p.p.m.). The consumption and foraging capacity were significantly impaired especially in the second-instar larval beetles which took longer time (more than twice of the control beetles) to consume whitefly eggs after exposure to toxins, although D. catalinae suffered no significant effect on fecundity and longevity, when exposed to a toxin dilution of field rate. The data suggest that spraying of V. lecanii or its toxins should be avoided in the field having immature stages of D. catalinae .     

Effects of plant and prey characteristics on the predatory behavior of Delphastus catalinae

Nymphal setosity of the whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) has been reported to be induced by mechanical stimuli such as leaf tomentosity, and related to the predatory performance of the coccinellid Delphastus catalinae (Horn) (Coleoptera: Coccinellidae). In this study, a possible adaptive value of this phenomenon for the whitefly is shown through the combined effects of leaf and prey characteristics on the walking and predatory behaviors of the beetle. Leaf tomentosity significantly affected the walking patterns of the beetle and therefore its searching abilities, thus indirectly increasing the influence of prey distribution upon predator's efficiency. Moreover, while searching on tomentose leaves, the beetles showed preference for the smooth prey phenotype. This behavior was found dependent on the experience of the beetle in previous encounters. These results are pertinent to intraspecific competition between the different nymphal phenotypes and to the predatory efficiency of this beetle, which is utilized in biological control of whiteflies.     

Geographic Origin and Taxonomic History of Delphastus spp. (Coleoptera: Coccinellidae) in Commercial Culture

Most of the published studies of Delphastus pusillus biology and behavior on Bemisia spp. actually refer to D. catalinae. Similarly, Delphastus species in commercial insectary cultures are probably D. catalinae and not D. pusillus. We discuss the historical reasons for the clouded identity of these native coccinellid beetles.     

Plant interspecies competition for sunlight: a mathematical model of canopy partitioning

We examine the influence of canopy partitioning on the outcome of competition between two plant species that interact only by mutually shading each other. This analysis is based on a Kolmogorov-type canopy partitioning model for plant species with clonal growth form and fixed vertical leaf profiles (Vance and Nevai in J. Theor. Biol., 2007, to appear). We show that canopy partitioning is necessary for the stable coexistence of the two competing plant species. We also use implicit methods to show that, under certain conditions, the species’ nullclines can intersect at most once. We use nullcline endpoint analysis to show that when the nullclines do intersect, and in such a way that they cross, then the resulting equilibrium point is always stable. We also construct surfaces that divide parameter space into regions within which the various outcomes of competition occur, and then study parameter dependence in the locations of these surfaces. The analysis presented here and in a companion paper (Nevai and Vance, The role of leaf height in plant competition for sunlight: analysis of a canopy partitioning model, in review) together shows that canopy partitioning is both necessary and, under appropriate parameter values, sufficient for the stable coexistence of two hypothetical plant species whose structure and growth are described by our model. A. L. Nevai was supported in part by the National Institutes of Health, National Research Service Award (T32-GM008185) from the National Institute of General Medical Sciences (NIGMS).     

日本刀角瓢虫对不同番茄品种的产卵选择性及其影响因素

【目的】明确日本刀角瓢虫Serangium japonicum对叶毛密度和类型不同的番茄Lycopersiconesculentum品种的产卵选择性。【方法】以4个番茄品种(砧木101、闽粉樱1号、砧木301和以色列超级金刚)作为日本刀角瓢虫的寄主植物,观察番茄叶片背面超微结构,统计叶片背面叶毛类型及密度;用叶蝶法和植株法测定日本刀角瓢虫雌成虫在带烟粉虱Bemisia tabaci卵的4个番茄品种上的产卵量占比;并测定日本刀角瓢虫在这4个番茄品种叶片上的子代及成虫表现(生长发育、繁殖和捕食能力)以及对叶片的附着力,雌成虫对4个番茄品种健康叶片和受烟粉虱为害叶片的气味选择以及4个番茄品种叶碟和植株上日本刀角瓢虫卵被同类捕食的风险。【结果】4个番茄品种叶片背面叶毛类型均具有非腺毛和腺毛,其中,非腺毛有Ⅱ, Ⅲ和Ⅴ型,腺毛有Ⅰ, Ⅳ Ⅵ和Ⅶ型,且均以Ⅴ型非腺毛密度最高。以色列超级金刚叶片背面的叶毛密度显著低于其他3个供试番茄品种。日本刀角瓢虫偏好在以色列超级金刚上产卵,在以色列超级金刚、砧木101和闽粉樱1号上的繁殖力(165~223.92粒/雌)显著高于在砧木301上的(2809粒/雌)。日本刀角瓢虫子代由卵发育至成虫的历期在闽粉樱1号上最短(15.73 d),在砧木101上最长(23.00 d)。日本刀角瓢虫在4个番茄品种上的产卵选择性与子代表现及亲代表现无显著相关性,而与日本刀角瓢虫卵的被捕食风险存在显著正相关关系。日本刀角瓢虫在4个番茄品种上的产卵选择性与日本刀角瓢虫对番茄叶片的附着力及番茄叶片上各类型叶毛密度均无显著相关性。番茄的7种叶毛类型其叶毛密度在4个番茄品种上都存在显著差异,除番茄Ⅰ型腺毛密度与日本刀角瓢虫的繁殖力(30 d内单雌产卵量)存在显著负相关关系外,其他6种类型的叶毛密度与日本刀角瓢虫子代表现及亲代表现均无显著相关性。日本刀角瓢虫雌成虫对4个番茄品种的气味无明显偏好。日本刀角瓢虫卵在4个番茄品种叶蝶和植株上的被捕食比例差异显著。【结论】日本刀角瓢虫雌成虫偏好在叶毛密度低的番茄品种叶片上产卵,番茄腺毛对日本刀角瓢虫成虫生命活动影响显著。