猎物—捕食者系统排队模型

在种群动态研究中,猎物——捕食者系统是种群自然控制的主要部分。鉴于数学模型较能方便而又准确地刻划猎物、捕食者数量变动的状况,因此,引入数学模型便成为研究该系统的有效途径。本文以 Holling 圆盘方程为背景,较为详尽地介绍了捕食者捕食过程与排队过程之间的相似特征,并导出用于分析猎物——捕食者系统的排队模型。     

饱食和功能反应的关系——一个新模型的建立和测验

1.通过对捕食者因饱食而导致其搜寻时间T_s减少的讨论,发展了捕食者对于猎物密度的功能反应模型。2、对于大个体猎物捕食者的饱食发生在每一次捕获到物借之后,T_s也因一系列的攻击循环中的攻击时间和消化暂停的时间而减少。对于小个体的猎物,捕食者在低猎物密度条件下会不停地觅食。其搜寻时间T_s只因突击时间而减少,如果猎物密度高,则捕食者的饱食发生在捕获到几个小个体的猎物之后,T_s因一系列觅食循环中的攻击时间和消化暂停而减少。3、通过把瓢虫成虫和幼虫的大食蚜虫量,同用实验估计的参数值预测的被猎物获量的极限值进行比较,验证了本文所描述的饱食模型。4、本文还根据处理时间(th)这一概念和一些瓢虫种类在生物防治申取得成功的几个例子讨论了捕食者因饱食而对猎物的捕食所受到的限制。     

不同稻区节肢动物群落中捕食者与猎物的种类与数量特征

根据在浙江富阳、江苏句容和河南郑州，对三种不同生态类型稻区节肢动物群落的系统调查，明确了捕食性天敌与其猎物在种类和数量上的相互作用以及季节动态方式。用经过原点的直线回归分析，捕食者的种类是猎物的１．５２５倍。从数量上看，猎物多于捕食者，二者平均比率约为１：４。捕食者与猎物之间具有跟随现象，但一般滞后７～１４天。优势种捕食者如黑肩绿盲蝽、狼蛛、微蛛及食虫沟瘤蛛对以白背飞虱、褐飞虱（富阳、句容）、黑尾叶蝉、灰飞虱（郑州）为主的害虫种群具有显著的控制效应，应注意保护利用。     

应用血清学技术研究捕食者与猎物关系的现状及问题

本文介绍近40年来国内外学者应用血清学技术,研究捕食者与猎物之间的关系;并评价了几种试验方法,认为酶联免疫吸附试验技术的灵敏度及特异性较高。     

一种估计捕食作用系数的新方法

关于天敌对猎物选择捕食作用的表述和测度,前人曾提出过不少方法或公式。例如Murdoch(1969)以如下形式定义了捕食者对猎物的选择:Na_1/Na_2=C_1N_1/N_2其中 C_1为选择参数,Na_1和 Na_2 为捕食者捕食两种不同猎物的数量,N_1和 N_2为两种不同猎物的数量。C_1>1说明捕食者选择的是 N_1;C_1<1说明选择的是 N_2;C_1=1说明对两种猎物的喜好程度一致。他还提出了 C_1的三种估计方法。此公式虽能表明捕食者对两种猎物的选择,但不能直接估计选择系数,尚需进一步变换和演算。     

星豹蛛猎物甜菜夜蛾电泳检测的初步研究

应用聚丙烯酰胺凝胶电泳技术,对星豹蛛(Pardosa astrigera)捕食猎物甜菜夜蛾(Laphygma exigua)前后酯酶同工酶的变化进行了电泳分析。结果表明:星豹蛛捕食猎物前后其酯酶同工酶在数目、迁移率及活性方面均有明显区别;应用电泳方法研究捕食者和猎物之间的关系,具有简便、直接且灵敏度高等优点。     

星豹蛛猎物甜菜夜蛾电泳检测的初步研究

应用聚丙烯酰胺凝胶电泳技术,对星豹蛛(Pardosa astrigera)捕食猎物甜菜夜蛾(Laphygma exigua)前后酯酶同工酶的变化进行了电泳分析。结果表明:星豹蛛捕食猎物前后其酯酶同工酶在数目、迁移率及活性方面均有明显区别;应用电泳方法研究捕食者和猎物之间的关系,具有简便、直接且灵敏度高等优点。     

中性昆虫在稻田节肢动物群落中作为捕食者营养桥梁作用的研究

在稻田节肢动物群落中，与水稻无直接营养关系的中性昆虫，如摇蚊、蚊、蝇、弹尾虫等，构成了捕食者猎物的重要组分。系统分析显示，中性昆虫在水稻生长前期为主要的猎物，其丰盛度的比例可高达９０％以上（富阳早稻）。相应地，结网类蜘蛛由于可以大量取食中性昆虫猎物，其个体数量占捕食性天敌的５０％以上，优势种有食虫沟瘤蛛（富阳和句容稻区）、锥腹肖蛸（郑州稻区）等。在一定条件下，结网类捕食者与中性昆虫相对丰盛度的季节动态呈正相关。从农田生态系统的整体性考虑，中性昆虫的生态学意义有必要进一步深入研究     

自然条件下拟环紋豹蛛对三化螟成虫捕食作用的评价

实验室条件下研究了不同空间容积大小和捕食者个体间的干扰作用对功能反应的影响,建立了参数方程和模拟模型。在此基础上,结合血清方法,提出了自然条件估算捕食者对猎物捕食数量的一种方法。该方法可用于评价自然条件下天敌对害虫的控制作用。     

不同蚜量密度对两种瓢虫幼虫的捕食量及其生长发育的影响

龟纹瓢虫Propylaea japonica (Thungberg)和异色瓢虫Harmonia_axyridies(Pallas)是棉田捕食棉蚜的优势天敌种类。在自然情况下,其种群密度较大,尤其是其幼虫扩散范围小,能较稳定地抑制蚜虫增长,对控制蚜害起着重要作用。为进一步明确它们与被捕食者之间的关系,更好地利用捕食潜能,我们于1983年至1984年对两种瓢虫幼虫在不同猎物密度下的捕食效应及猎物密度对其生长发育的影响作了初步研究。     

转Bt基因作物对植物—害虫—天敌食物链的影响

种植转Bt基因作物已经成为当前及未来农业的发展趋势。转Bt基因作物可以有效控制棉铃虫（〖WTBX〗Helicoverpa armigera〖WTBZ〗）、玉米螟（〖WTBX〗Ostrinia furnacalis〖WTBZ〗）等多种靶标害虫。但研究表明Bt作物的种植会改变害虫演化地位,并且Bt毒素可能沿着食物链传递,而对天敌构成潜在的威胁。基于Bt作物对植物—害虫—天敌食物链上各个营养级的影响研究,本文重点分析了Bt毒素对天敌种群结构及生物学的影响。     

Predator–prey Systems with Mites1)

Population models of fruit tree red spider mite and predatory mite are given, which are used to explain the regulation of spider mites by predatory mites and may be used to manage spider mite systems in apple orchards. The models are based on extensive experimental knowledge of the bionomics of prey and predator. A detailed analysis of the prey–predator relations on the individual level paved the way for the development of prey–predator models on the population level. These models, based on the state variable approach, simulate the population fluctuations: of prey and predator in dependence of the changing abiotic factors during the season using time steps of a quarter of an hour and trace all state variables, as the number of eggs, larvae, adult females and gut content of the adult female predator. Verification of the models at different levels of integration showed good agreement between model output and the results of independent experiments, and this enabled a sensitivity analysis with the model. This sensitivity analysis showed the relative importance of different factors, so that management strategies to achieve tolerable prey–predator levels throughout the year may be developed.     

Biology and predation rate of the sarcophagid fly,Agria mamillata a predator of European small ermine moths

Abstract

The biology of the univoltine, predatory sarcophagid fly Agria mamillata (Pandellé) was studied in a population of Yponomeuta evonymellus(L.) (Yponomeutidae) attacking Prunuspadus L. in the Valais, Switzerland. Clarification of the literature records suggests that A. mamillata is oligophagus, attacking five Yponomeuta species in the Palaearctic. The adult flies emerged in May. The presence of host odour was advantageous to elicit mating. After a preoviposition period of 19 days, the ovolarviparous females deposited eggs/first instar larvae on the cuticle of late fifth instar prey larvae, or on cocoons of prey pupae. The potential fecundity averaged 40 eggs per female. Reid data indicated that females of the predator laid more eggs in tents with higher prey density. Larval development lasted 11 days. Rain stimulates mature predator larvae to leave the tents of Y. evonymellus to pupate in the soil. Pupation was observed between early July and mid August. Predation rates ( = number of prey eaten per predator) were estimated from laboratory food consumption tests and from the number of predator larvae and predated cocoons in prey tents in the field. It was shown that a single predator consumed an average of five Y. evonymellus individuals. Field data indicated that predation rates cannot increase with higher numbers of prey available. It was shown that the number of prey eaten per predator decrease with higher predator densities per tent in the field.     

Overview of a Passive Tracking Index for Monitoring Wild Canids and Associated Species

Population density estimates for many animal species are often difficult or expensive to obtain, and they rely on assumptions that, if violated, result in unmeasurable estimation errors. Density estimates also may be unnecessary for research or management purposes, because an index that tracks changes in a population within appropriate time and geographic constraints could provide the information necessary to make management decisions or to evaluate the impact of a control program. We review research on a passive tracking index where observations are made on a series of tracking plots placed on lightly used dirt roads. The number of sets of tracks (individual intrusions) are recorded for each species of interest on each plot on consecutive days. The mean number of intrusions over the plots is calculated for each day for each species. The index is the mean of the daily means. These design and measurement methods present valuable advantages over most traditional tracking plot methods. Because no scents or baits are used as attractants, no conditioning of animals to the plots biases the results. This also permits multiple species, predator and prey alike, to be simultaneously monitored. Using the number of animal intrusions as observations produces results that are far more sensitive to change than tracking surveys where only presence or absence of spoor are recorded for each plot. Of particular importance, the statistical properties inherent to this data structure permit calculation of standard errors, confidence intervals and statistical tests, without subjectively subdividing the data.     

不同Bt杀虫蛋白通过食物链对大草蛉的影响

为了明确目前转基因抗虫植物中表达的Bt蛋白对农田重要捕食性天敌大草蛉的生态安全性,采用三级营养食物链评价体系,分别以对供试Bt蛋白Cry1Ac、Cry1F和Cry2Ab具有抗性的靶标害虫或不敏感的非靶标害虫作为大草蛉的猎物,研究了供试3种蛋白对大草蛉的影响。结果表明,当大草蛉以抗性棉铃虫（抗Cry1Ac或Cry2Ab）或抗性玉米螟（抗Cry1F）为猎物时,供试3种Bt蛋白通过食物链对大草蛉幼虫（4龄幼虫重量和幼虫发育至蛹历期）、蛹（化蛹率、蛹重和蛹发育历期）及成虫（羽化率、雌虫重量、雄虫重量和单雌产卵量）的生长发育及产卵量均无显著影响;同样地,当大草蛉以对3种Bt蛋白不敏感的非靶标昆虫——绿盲蝽作为猎物时,通过食物链传递的Bt蛋白对大草蛉生长发育及繁殖也无显著影响。因此,目前转基因棉花、玉米或水稻中广泛表达的Cry1Ac、Cry1F和Cry2Ab蛋白,通过三级营养食物链,对大草蛉生长发育及繁殖均无潜在毒性。     

Should I fight or should I flight? How studying insect aggression can help integrated pest management

Aggression plays a key role all across the animal kingdom, as it allows the acquisition and/or defence of limited resources (food, mates and territories) in a huge number of species. A large part of our knowledge on aggressive behaviour has been developed on insects of economic importance. How can this knowledge be exploited to enhance integrated pest management? Here, I highlight how knowledge on intraspecific aggression can help IPM both in terms of insect pests (with a focus on the enhancement of the sterile insect technique) and in terms of biological control agents (with a focus on mass‐rearing optimisation). Then, I examine what implications for IPM can be outlined from knowledge about interspecific aggressive behaviour. Besides predator–pest aggressive interactions predicted by classic biological control, I focus on what IPM can learn from (i) interspecific aggression among pest species (with special reference to competitive displacement), (ii) defensive behaviour exhibited by prey against predaceous insects and (iii) conflicts among predaceous arthropods sharing the same trophic niche (with special reference to learning/sensitisation practices and artificial manipulation of chemically mediated interactions). © 2015 Society of Chemical Industry     

DNA分子检测技术在节肢动物食物网结构解析中的应用

生态系统中节肢动物食物网结构错综复杂，通过观察和解剖等传统手段往往很难精准地获得物种种类及彼此之间食物关系的全面信息。近年来，DNA分子检测技术快速发展，显著促进了节肢动物食物网复杂结构的系统解析，有效实现了食物网结构分析由定性向定量的重要转变。该文介绍DNA分子检测的主要技术及其优缺点，列举其在节肢动物食物网结构分析中的应用实例，讨论DNA分子检测技术在应用中遇到的问题及挑战，旨在为节肢动物食物网结构分析提供科学依据和技术指导，有力推进农田等不同生态系统中节肢动物食物网结构及其生态功能的深入研究和挖掘利用。     

捕食者—猎物功能反应的统计模型研究

以往关于捕食者－猎者功能反应的数学模型大多是用微分方程和概率极限定理的方法来推导的。本文采用回归分析，系数显著性检验的方法，直接从实际统计数据出发，得出捕食者－猎物功能反应的统计模型，它是一种拟合得很好的不同以往的模型，为捕食者－猎物功能反应研究提供了一种新的方法。     

Plant food effects on prey consumption by the omnivorous predator Macrolophus pygmaeus

Omnivorous predatory Heteroptera are important biological control agents of pests in several crops. They can feed on plant food resources that may positively affect their biological characteristics. In the current paper, the influence of leaves and flowers on the predation rate of the omnivorous predator Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) was investigated. Its predation rates were recorded on prey offered on (a) a single leaf of tomato, pepper or black nightshade (Solanum nigrum), or (b) a leaf of pepper or S. nigrum plus flowers of pepper or S. nigrum, respectively. In all cases the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) was used as prey at densities of 4, 8, 12, 16, 20 and 24 nymphs of the second instar. The experiments were conducted in petri dishes at 25 ± 1°C and prey consumption was evaluated after 24 h. The predation rate of M. pygmaeus was significantly higher on leaves of S. nigrum than on those of pepper at the prey density of 20 prey items. Therefore, the hypothesis that increased predation rates should occur on plants of lower suitability for development or reproduction was not supported under our experimental conditions. The flower availability did not alter the prey consumption among the prey densities on S. nigrum. However, the presence of a pepper flower caused a significant decrease in the predation rates on pepper leaves, at prey densities higher than eight prey items. Thus, pepper flowers can provide the predator with nutrient sources that may partially substitute for prey consumption, with practical implications in biological control.     

Toxicity of thiamethoxam to Tetranychus urticae Koch and Phytoseiulus persimilis Athias-Henriot (Acari Tetranychidae, Phytoseiidae) through different routes of exposure

BACKGROUND: Knowledge of the impact of insecticides on Tetranychus urticae Koch and its predator Phytoseiulus persimilis Athias‐Henriot is crucial for IPM. This study evaluates the effect of thiamethoxam on T. urticae and its predator by considering different routes of exposure (topical, residual and contaminated food exposures) and their combinations. RESULTS: Thiamethoxam effects on T. urticae were higher when residual and contaminated food exposures were considered. The total effect was higher than 90% where contaminated food exposure was involved. On P. persimilis, the total effect was higher in residual and contaminated prey exposures compared with topical exposure, and all combinations of routes of exposure attained a total effect higher than 90%. CONCLUSION: Thiamethoxam was found to be toxic to T. urticae and P. persimilis; however, the impact of the insecticide depended on the routes of exposure and their combinations. Lethal and sublethal effects occurred in residual and contaminated food exposures, while only sublethal effects occurred in topical exposure of predators and prey. The toxicity of thiamethoxam on prey and predator increased with the number of exposure routes involved. By limiting exposure to thiamethoxam to ingestion of contaminated food only, the impact of the pesticide was more favourable to P. persimilis than to its prey. Copyright © 2010 Society of Chemical Industry