纽氏钝绥螨、尼氏钝绥螨及其猎物—桔全爪螨生态学特性的比较研究

本文从天敌与猎物的种群内禀增长力,天敌对猎物不同密度的功能反应及数值反应三个方面来评价和比较纽氏钝绥螨、尼氏钝绥螨时其猎物——枯全爪螨的控制作用。在五种温度下,两种捕食螨的种群内禀增长力都大于桔全爪螨。它们对猎物的功能反应属HollingⅡ型。尼氏钝绥螨的捕食量大于纽氏钝绥螨,在25℃时两种捕食螨捕食量最大,应用Rogers的模型能较好地对试验结果进行模拟。尼氏钝绥螨对桔全爪不同虫态的取食不存在选择效应,纽氏钝绥螨则嗜食若螨和幼螨。两种捕食螨对桔全爪螨的数值反应表明,仅供给桔全爪螨雌成螨作为食物,对两种捕食螨都不利,尤其对尼氏钝绥螨更为明显。综上所述,两种捕食螨能比较有效地控制桔全爪螨种群,当猎物密度较高时,尼氏钝绥螨控制效果优于纽氏钝绥螨,但纽氏钝绥螨控制效果优于纽氏钝绥螨,但纽氏钝绥螨田间种群数量比尼氏钝绥螨稳定。柑桔园中存在其它补充食物时对这两种捕食敌有利。     

定量评价天敌控害功能的生态能学方法

由于昆虫的能量完全来自于寄主,因此昆虫摄入的能量相当于食物的被取食消耗量。生态能量学方法的基本原理就是捕食性天敌完全依靠捕食猎物(害虫)而获取能量。显然,捕食性天敌摄入的能量就相当于为猎物(害虫)的被捕食消耗量,也即是捕食性天敌摄入量等于猎物(害虫)的被捕食消耗量。由此,可通过研究捕食性天敌和害虫种群的能量动态,定量分析捕食性天敌对害虫的控制作用。本文详细论述了生态能量学方法的基本原理、测算方法,并以棉田捕食性瓢虫类捕食作用为例,介绍了该方法的应用,为定量评价天敌的控害作用提供了一种新方法。     

武汉东西湖棉田蜘蛛资源调查

1985—1988年在武汉东西湖棉区,对棉田蜘蛛群落结构和数量动态进行了调查,现报告于下。1调查方法1985—1988年在武汉市东西湖棉区,分季节不定期地随机采集棉田内的蜘蛛种类、害虫种类及其它捕食性天敌;在调查棉区选择不同类型的棉田进行定期定点系统调查。每块田按大五点取样法。每隔五天调查一次。2结果与分析2.1棉田害虫和捕食性天敌群落的种类组成通过几年调查发现在当地为害棉花的节肢动物23种,分属8目13科;捕食性天敌45种,分属7目21科,其中昆虫13种,捕食螨2种,蜘蛛30种。表1棉田蜘蛛与其它捕食性天敌发生量(%)的比较(1985)五月六月七月…     

剑毛帕厉螨对韭蛆捕食功能反应的研究

【目的】韭菜是广受人们喜爱的蔬菜,韭菜迟眼蕈蚊Bradysia odoriphaga YangZhang是近年来危害韭菜的重要根部害虫,长期过量施用剧毒化学农药已严重影响了人们的健康和造成环境的污染,挖掘和筛选有效防控韭蛆的天敌迫在眉睫。剑毛帕厉螨Stratiolaelaps scimitus是一种与韭蛆栖境相同的捕食性天敌螨类。目前尚未有关于剑毛帕厉螨对韭蛆的捕食功能反应的研究。【方法】测定了剑毛帕厉螨对1龄韭蛆的捕食作用和种内干扰对其捕食能力的影响。【结果】该螨对1龄韭蛆的捕食功能反应符合HollingⅡ型;随着捕食螨密度的增加,该螨成虫间存在相互干扰作用;其搜寻效应随猎物密度的增加而下降,表明猎物对捕食作用的干扰较明显。【结论】剑毛帕厉螨是一种有效防治韭蛆的天敌,有较好的应用前景。     

圆果大赤螨对桑树害虫的捕食功能反应

在室内条件下研究了圆果大赤螨对桑树害虫朱砂叶螨、桑蓟马和桑粉虱的捕食作用。结果表明,圆果大赤螨对3种猎物的捕食功能反应均符合HollingⅡ功能反应模型,经χ2检验,理论值与观测值差异不显著。捕食功能反应参数表明圆果大赤螨对桑蓟马、朱砂叶螨和桑粉虱捕食量差异显著,其最大日捕食量理论值分别为:416.67、222.22、97.09头。圆果大赤螨对猎物的搜寻效应均随猎物密度的增加而呈线性下降,且取食桑蓟马的搜寻效应明显高于朱砂叶螨和桑粉虱。HollingⅢ型功能反应新模型拟合得出,1头圆果大赤螨对桑蓟马、朱砂叶螨、桑粉虱的最佳寻找密度分别为77.54头、70.49头和27.27头。研究表明,圆果大赤螨对桑树害虫捕食能力依次为桑蓟马朱砂叶螨桑粉虱,且对3种害虫均具有较强捕食能力,是桑园害虫的重要天敌资源。     

不同环境温度下大草蛉对黄精主要害虫二斑叶螨的控害潜能评估

以重要中草药黄精Polygonattum sibiricium的主要害虫二斑叶螨Tetranychus urticae为研究对象,在5个温度(15℃、20℃、25℃、30℃及35℃)条件下,测定了大草蛉Chrysopa pallens雌成虫对二斑叶螨的捕食功能反应及搜索效应。试验结果表明,在温度处理设置范围内,各温度下大草蛉对二斑叶螨的捕食功能反应均拟合HollingII功能反应模型。大草蛉对二斑叶螨的捕食,受温度及猎物密度影响显著。而在各温度处理间,以25℃下的瞬间攻击率最大为0.664,而猎物处理时间最短为0.025d。瞬间攻击率在高温及低温条件下均低于25℃。但猎物处理时间则呈显出相反的趋势。基于捕食功能反应结果计算的搜索效应表明,大草蛉对二斑叶螨的搜索效应在各温度处理内随猎物密度增加而线性上升,其中以25℃下的捕食效应最高,而在15℃下的最低。本研究结果表明,大草蛉雌成虫作为一种捕食性天敌,对黄精上的二斑叶螨具有一定的控害潜能,并且其取食能力受环境温度影响显著。     

应用DNA条形码构建天敌-猎物食物网的方法

定量构建天敌-猎物食物网是有效开展害虫管理的基础.常用的食物网构建方法有单克隆抗体法、肠道内容物的PCR检测法、实时荧光定量PCR法等.这些方法灵敏度高、特异性强,但只能定性或定量检测天敌对已知猎物物种,即已明确捕食或寄生关系的物种的捕食情况,并不能检测未明确捕食或寄生关系的猎物种类和捕食量.而DNA条形码是一段具有物...     

稻田穗期主要捕食性天敌对两种盲蝽集团内捕食的初步研究

【目的】集团内捕食是影响农业系统广食性天敌对靶标害虫控制作用的重要因素,全面揭示稻田广食性天敌对稻飞虱重要天敌黑肩绿盲蝽Cyrtorhinus lividipennis Reuter和中华淡翅盲蝽Tytthus chinensis(St?l)(半翅目:盲蝽科)的集团内捕食作用有助于更好地保护利用天敌。【方法】建立以两种盲蝽为猎物对象的种特异性二重定量PCR系统,检测比较不同抗性品种穗期田间主要捕食者对两种盲蝽的集团内捕食作用。【结果】(1)本研究建立的二重定量PCR具有的物种专化性,两种检测靶标灵敏度高且相似,可用于田间捕食者猎物分析;(2)感虫水稻品种上捕食者对盲蝽的捕食强度高于抗性水稻品种;不同种类捕食者对盲蝽的集团内捕食强度有显著差异;捕食者对黑肩绿盲蝽集团内捕食强度显著高于中华淡翅盲蝽。【结论】捕食性盲蝽在稻田生态系统遭遇集团内捕食,其集团内捕食强度与水稻品种抗性、捕食者种类和猎物丰富度有关。     

拟环纹狼蛛对褐飞虱的捕食作用及其模拟模型的研究Ⅲ.选择捕食作用

本文研究了拟环纹狼蛛雌成蛛对褐飞虱、稻纵卷叶螟的选择捕食作用。在不同猎物类型共存和不同总猎物密度下,测定了捕食者对猎物的喜好性和转换行为,分析了捕食者对猎物的功能反应形式,喜好性和转换行为与共存猎物种类、数量之间的关系;建立了在多种猎物类型共存时,雌成蛛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。室内验证实验表明:所建立的捕食作用方程具有一定的描述能力。     

捕食性天敌昆虫控害作用定量评价方法

天敌昆虫田间捕食作用与能力的研究,通常采用田间种群数量调查与分析的方法或笼罩试验来评价其控制作用,但往往与实际情况不符,尤其是对可捕食多种猎物的非专食性天敌,很难说明其在田间对某一特定猎物的控制作用究竟有多大,而分子生物学技术为捕食者-猎物关系评价研究提供了新途径。本文系统介绍了基于种特异性SS-PCR标记技术和TaqMan-MGB实时荧光定量PCR技术的捕食性天敌控害作用定量评价方法及其优缺点,旨在为害虫天敌的种类筛选及其保护利用提供技术指导。     

具有脉冲投放捕食者阶段结构时滞的捕食-食饵模型

讨论了具有阶段结构脉冲时滞的HollinglI功能反应的捕食模型,其中天敌（益虫）进行人工脉冲周期投放,害虫具有阶段结构及成熟期的时滞现象,并进行了系统的数学及生物方面的研究．利用脉冲及时滞微分方程的基本知识证明了该害虫根除周期解的唯一性和全局吸引性．进一步证明了当天敌的投放量或者投放周期在一定的范围内,能够控制害虫在作物的经济危害水平（EIL）运行的情况下使天敌与害虫可以共存．得出的结论为害虫治理提供了策略基础．     

大豆田节肢动物群落优势种群时间生态位及营养关系分析

【目的】阐明大豆田节肢动物群落时间生态位及营养关系,为大豆害虫生态调控手段的实施提供坚实的理论依据。【方法】以大豆田节肢动物群落为研究对象,通过两年的田间系统调查分析。【结果】统计得到种类220余种,物种可分为天敌、害虫和中性昆虫3个类群,以天敌物种丰富度最高;害虫中以烟蓟马Thrips tabaci(0.36902)和大豆蚜Aphis glycines(0.13122)优势度最高,且有着较高的生态位重叠指数(0.8163),蚜小蜂Aphytis sp.和大草蛉Chrysopa septempunctata对害虫的时间生态位重叠指数很高,其他天敌如异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、黑带食蚜蝇Zyistrophe balteata和黑食蚜盲蝽Deraeocoris punctulatus等对害虫的重叠指数居中;大豆田中各类群构成错综复杂的食物网结构。【结论】综合考虑天敌的种群数量,确定捕食性天敌是控制害虫种群数量的有效天敌。研究可知不能单纯从时间生态位的重叠指数的高低来判断天敌的控制能力。     

In search of artificial domatia for predatory mites

Banker plants can enhance biological pest control by providing both floral resources and appropriate oviposition sites, e.g. through acarodomatia, to predator species. The use of materials mimicking domatia i.e. artificial domatia may be an economically favourable alternative to the use of banker plants bearing domatia. The aim of the present study was to identify materials that are able to host eggs of the Neoseiulus californicus predatory mite but not those of the Tetranychus urticae pest mite. In a laboratory experiment, the oviposition of predatory and phytophagous mites were compared in Petri dishes containing leaves. The different modalities compared were (i) natural domatia of Viburnum tinus or (ii) one of twelve potential artificial domatia materials. The overall oviposition response of predatory mites to all artificial domatia was similar to that of the natural domatia. The oviposition of the Tetranychus urticae pest mite did not increase in response to the artificial domatia. Five artificial domatia hosted as many eggs of the predatory mite as observed in the natural domatia. The effect of the physical properties of artificial domatia was also tested and N. californicus was found to favour the artificial domatia that had high heat retention capacities for oviposition. Three of these artificial domatia were tested on rose plants in a greenhouse experiment; none of which enhanced the biological control on the plants under these conditions. The present study highlights the difficulty in identifying and using suitable artificial domatia as substitutes to banker plants in biological pest control efforts.     

Reciprocal effects of host plant and natural enemy diversity on herbivore suppression: an empirical study of a model tritrophic system

Many theoretical and empirical studies have shown that species diversity in a trophic level can impact the capture of limited resources in ways that cascade up or down a food web. Only recently, however, have ecologists begun to consider how diversity at multiple trophic levels might act in concert to have opposing or reinforcing effects on resource use. Here, we report the results of an empirical study of a model, tritrophic food web in which we manipulated the diversity of host plant species ( Medicago sativa , Trifolium pratense and Vicia faba ) and natural enemy species ( Harmonia axyridis , Coleomegilla maculata and Nabis sp.) of a widespread herbivorous pest (the pea aphid, Acyrthosiphon pisum ) in laboratory microcosms. We found that increasing natural enemy richness from one to three species increased the proportion of aphids consumed by 0.14. This effect of enemy diversity was due to facilitative interactions and/or a reduction in intraspecific competition in the more diverse assemblages. We also found an independent and additive main effect of host plant richness, with the proportion of aphids consumed by natural enemies decreasing by 0.14 in plant polycultures. A reduction in predator efficiency on a single host plant, Vicia faba , appeared to be responsible for this plant diversity effect. Aphid population sizes were, therefore, simultaneously determined by a top-down effect of natural enemy diversity, and an opposing bottom-up effect of host plant diversity that modified enemy–prey interactions. These results suggest that population sizes in nature, and biotic controls over insect pests, are influenced by species diversity at multiple trophic levels.     

Functional benefits of predator species diversity depend on prey identity

Abstract.  1. Determining the functional significance of species diversity in natural enemy assemblages is a key step towards prediction of the likely impact of biodiversity loss on natural pest control processes. While the biological control literature contains examples in which increased natural enemy diversity hinders pest control, other studies have highlighted mechanisms where pest suppression is promoted by increased enemy diversity.
2. This study aimed to test whether increased predator species diversity results in higher rates of predation on two key, but contrasting, insect pest species commonly found in the rice ecosystems of south-east Asia.
3. Glasshouse experiments were undertaken in which four life stages of a planthopper ( Nilaparvata lugens ) and a moth ( Marasmia patnalis ) were caged with single or three-species combinations of generalist predators.
4. Generally, predation rates of the three-species assemblages exceeded expectation when attacking M. patnalis , but not when attacking N. lugens. In addition, a positive effect of increased predator species richness on overall predation rate was found with M. patnalis but not with N. lugens .
5. The results are consistent with theoretical predictions that morphological and behavioural differentiation among prey life stages promotes functional complementarity among predator species. This indicates that emergent species diversity effects in natural enemy assemblages are context dependent; they depend not only on the characteristics of the predators species, but on the identity of the species on which they prey.     

More pests but less pesticide applications: Ambivalent effect of landscape complexity on conservation biological control

In agricultural landscapes, the amount and organization of crops and semi-natural habitats (SNH) have the potential to promote a bundle of ecosystem services due to their influence on ecological community at multiple spatio-temporal scales. SNH are relatively undisturbed and are often source of complementary resources and refuges, therefore supporting more diverse and abundant natural pest enemies. However, the nexus of SNH proportion and organization with pest suppression is not trivial. It is thus crucial to understand how the behavior of pest and natural enemy species, the underlying landscape structure, and their interaction, may influence conservation biological control (CBC). Here, we develop a generative stochastic landscape model to simulate realistic agricultural landscape compositions and configurations of fields and linear elements. Generated landscapes are used as spatial support over which we simulate a spatially explicit predator-prey dynamic model. We find that increased SNH presence boosts predator populations by sustaining high predator density that regulates and keeps pest density below the pesticide application threshold. However, predator presence over all the landscape helps to stabilize the pest population by keeping it under this threshold, which tends to increase pest density at the landscape scale. In addition, the joint effect of SNH presence and predator dispersal ability among hedge and field interface results in a stronger pest regulation, which also limits pest growth. Considering properties of both fields and linear elements, such as local structure and geometric features, provides deeper insights for pest regulation; for example, hedge presence at crop field boundaries clearly strengthens CBC. Our results highlight that the integration of species behaviors and traits with landscape structure at multiple scales is necessary to provide useful insights for CBC.     

六盘山翠金小蜂生物学特性的研究

六盘山翠金小蜂Tritneptis sp.是华北落叶松人工林主要食叶害虫落叶松红腹叶蜂Pristiphora erichsonii Hartig茧期的体外复寄生性天敌。对该蜂的生物学特性研究表明,该蜂在宁夏六盘山1年2代,以幼虫在寄主茧内越冬,翌年4月中旬开始活动取食,5月中旬开始化蛹,成蜂从6月中旬开始羽化,每头虫茧平均出蜂6.14头,雌雄比1.79∶1,雌蜂6月下旬开始产卵,一只雌蜂一生可在12.2头寄主虫茧上产卵,第1代寄生蜂幼虫7月上旬开始孵化并吸食寄主营养发育,7月下旬开始化蛹,8月上旬开始羽化并交尾、产卵寄生。该蜂体型较大,对寄主跟随性强,无重寄生天敌,自然寄生率7.3%～33.6%,是一种优良天敌寄生蜂。     

Stigmaeid-phytoseiid interactions and the impact of natural enemy complexes on plant-inhabiting mites

Interactions within the natural enemy complex of plant-inhabiting mites are of practical interest. There are frequently several predatory mite species present or available for introduction and it is difficult to tell whether a single species or combination of species should provide the most effective means of biological control. We used a simulation model to examine the interactions between predatory mites of two families, the Stigmaeidae and Phytoseiidae, representatives of which feed on phytophagous apple mites. To identify key differences in predatory behavior and life history, various stigmaeid parameters were substituted with those of phytoseiids, and changes in the efficacy of either stigmaeids alone or in combination with phytoseiids were evaluated graphically. At low prey densities stigmaeids held an advantage over phytoseiids in terms of efficacy because of their higher preference for prey eggs, higher oviposition relative to prey consumption and the ability to consume their own eggs, while at high prey densities the higher maximum predation rate of phytoseiids gave them a higher efficacy. Thus the weaker predator (the stigmaeid) is the more effective competitor at low prey densities. The model did not account for dispersal, but since stigmaeids are the weaker dispersers, the possibility of developing stability in this system is much greater than if phytoseiids were the better competitors. A combination of stigmaeids and phytoseiids was shown to have greater efficacy than either predator alone over a wide range of prey densities.     

一类具有脉冲效应和Ⅲ类功能反应的捕食系统分析

本文讨论了一类具有HollingⅢ类功能性反应的捕食系统,通过对捕食者(天敌)实行周期投放,对食饵(害虫)实行周期喷洒农药的策略来控制害虫,结果证明,当投放和喷洒周期T<1/aln1/(1-p)时,是一种控制害虫的非常有效的方法.