拟长毛钝绥螨对朱砂叶螨的捕食作用研究

研究了拟长毛钝绥螨(Amblyseus pseudolongispinosus)对朱砂叶螨(Tetranychus cinnabarinus)的捕食作用.结果表明,拟长毛钝绥螨若螨和雌成螨对朱砂叶螨各螨态的捕食功能反应,即捕食量与猎物密度之间呈逆密度制约关系,功能反应曲线属HollingⅡ型;对猎物卵和幼若螨的控制能力最强;猎物的螨态、生境大小等因素均可起拟长毛钝绥螨功能反应参数的变化;拟长毛钝绥螨的自身密度对功能反应存在密度制约作用;拟长毛钝绥螨对朱砂叶螨卵和幼若螨是嗜食的,对成螨是非嗜食的.     

虚伪钝绥螨的食性研究

在26℃恒温、相对湿度75％的条件下,虚伪钝绥螨取食朱砂叶螨、山楂叶螨和苹果叶螨的发育历期分别为6.08、6.68、6.54天,一生产卵总量分别为47.52、48.75、48.12粒。上述食料对虚伪钝绥螨的发育和生殖无明显差别。通过对22种植物花粉的筛选,证明其中18种花粉可使虚伪钝绥螨完成发育,12种可以使其产卵,而以苹果、桃的花粉最能满足虚伪钝绥螨的生育要求,如进一步明确这两种花粉对虚伪钝绥螨的后代生育能力无不良影响,就有可能用花粉来取代叶螨,在室内大量繁殖。     

应用尼氏纯妥螨防治大棚草莓上zhu砂叶螨的研究初报

尼氏钝绥螨能捕食ｚｈｕ砂叶螨各螨态，对卵的捕食量显著地高于其他螨态，其雌成螨对ｚｈｕ砂叶螨若螨的功能反应为ＨｏｌｌｉｎｇⅡ反应，在草莓大棚内释放尼氏钝绥螨能较好地防治ｚｈｕ砂螨叶螨若螨的功能反应为ＨｏｌｌｉｎｇⅡ反应，在草莓大棚内释放尼氏钝绥螨能较好地防治ｚｈｕ砂螨叶。     

巴氏钝绥螨对二斑叶螨的捕食功能反应

为明确巴氏钝绥螨Amblyseius barkeri(Hughes)对二斑叶螨Tetranychus urticae(Koch)的潜在控制能力,采用功能反应方法,在温度为16、20、24、28、32℃,相对湿度(85±5)%条件下对巴氏钝绥螨捕食二斑叶螨的效应进行了研究。结果表明:巴氏钝绥螨对二斑叶螨的卵和若螨表现为嗜食性,对雌成螨表现为非嗜食性。巴氏钝绥螨对二斑叶螨雌成螨、若螨和卵均有较强的捕食作用,捕食功能反应均拟合HollingⅡ型方程,在相同温度下对各螨态的捕食量大小为:卵若螨雌成螨。在16~28℃,巴氏钝绥螨对各螨态的瞬间攻击系数(a)、捕食能力(a/Th)、最大日捕食量(1/Th)均随温度的升高而增加,处理时间则缩短,当温度高于32℃时捕食量开始减小。当二斑叶螨密度固定时,巴氏钝绥螨的日平均捕食量则随其自身密度的增加而逐渐降低,说明巴氏钝绥螨存在明显的竞争和自我干扰作用。     

应用尼氏钝绥螨防治大棚草莓上硃砂叶螨的研究初报

尼氏钝绥螨(Amblyseius nicholsi Ehare＆Lee)能捕食硃砂叶螨(Tetranychuscinnabarinus Boisduval)各螨态,对卵的捕食量显著地高于其他螨态,其雌成螨对硃砂叶螨若螨的功能反应为HollingⅡ反应,在草莓大棚内释放尼氏钝绥螨能较好地防治硃砂螨叶     

真桑钝绥螨捕食朱砂叶螨的实验种群生命表及捕食作用

为评价真桑钝绥螨Amblyseius makuwa Ehara防治害螨的可能性,本试验在(25±1)℃、RH 80%±5%、光周期16L:8D的条件下,组建了真桑钝绥螨以朱砂叶螨Tetranychus cinnabarinus Boisduv为食的实验种群生命表,研究了真桑钝绥螨雌成螨对朱砂叶螨卵、若螨和雌成螨的捕食作用。结果表明,真桑钝绥螨以朱砂叶螨为食,未成熟期发育历期分别为卵期1.90 d,幼螨期0.62 d,前若螨期0.82 d,后若螨期1.26 d。试验条件下真桑钝绥螨净增殖率为11.80,内禀增长率为0.175,世代平均周期为14.12 d,周限增长率为1.191,种群倍增时间为3.96 d,雌成螨日均产卵量为1.22粒,平均总产卵量为22.12粒。真桑钝绥螨对朱砂叶螨3个螨态的捕食功能反应均属于HollingⅡ型圆盘方程,拟合圆盘方程显示真桑钝绥螨对朱砂叶螨卵的捕食数量最大,其次为若螨和雌成螨,a/Th值分别为12.5162、5.8730和4.4009。综上研究结果,真桑钝绥螨具备优良天敌的基本特性,是朱砂叶螨的潜在天敌之一。     

斯氏钝绥螨对朱砂叶螨若螨的捕食作用

在5个恒温条件下研究了斯氏钝绥螨Amblyseius swirskii(Athias-Henriot)不同螨态对朱砂叶螨Tetranychus cinnabarinus(Boisduval)若螨的功能反应.结果表明,在供试温度下,斯氏钝绥螨不同螨态对朱砂叶螨若螨的功能反应均属于Holling Ⅱ型.在相同猎物密度条件下,斯氏钝绥螨的捕食量随着自身密度的增加而下降,在16～28℃之间,随着温度升高斯氏钝绥螨对朱砂叶螨的捕食量增加、搜寻效应增强.斯氏钝绥螨的捕食作用存在较强的种内干扰反应,随着捕食者密度的增大,平均捕食量逐渐减少,捕食作用率也相应降低,捕食作用率与其自身密度的关系为E=0.330P-0.572.     

伪钝绥螨对二斑叶螨的捕食作用

室内条件下研究了伪钝绥螨对二斑叶螨的捕食作用。结果表明：伪钝绥螨雌成螨对二斑叶螨卵、幼螨、若螨和雌成螨的功能反应均符合HollingⅡ型方程,搜寻效率a′与处理时间Th值分别为0.5902、1.0025、0.9697、0.3146和0.0150、0.0240、0.0520、0.1681。伪钝绥螨的雌成螨喜食二斑叶螨的卵、幼螨和若螨,而对二斑叶螨雌成螨的捕食能力较弱。伪钝绥螨捕食率随着自身密度的增加而下降。捕食者密度低时,捕食率下降较快;随着捕食者密度进一步增加,捕食率下降缓慢,干扰反应方程拟合为E=0.3101P~（-0.412）。     

伪钝绥螨对叶螨与花粉的选择性

用朱砂叶螨和苹果或桃花粉同时喂饲伪钝绥螨,其若螨和雌成螨对朱砂叶螨有较强的选择性。叶螨的丝和粪的引诱作用增强了这种选择性。幼螨活动性差,取食量极小,对2类食物的选择性不明显。     

加州新小绥螨对朱砂叶螨不同螨态的捕食选择性及与拟长毛钝绥螨功能反应比较

加州新小绥螨是世界商品化品种,近年在国内首次发现。本文在25℃,RH(80±5)%,光周期16L:8D的条件下研究了加州新小绥螨雌成螨对朱砂叶螨3种螨态(卵、幼螨及若螨)的捕食喜好性,并与拟长毛钝绥螨对朱砂叶螨的功能反应进行了比较。结果表明,相对于朱砂叶螨卵(Ci为-0.09)与幼螨(Ci为-0.07),加州新小绥螨更喜食若螨(Ci为0.06)。当朱砂叶螨卵密度高于20粒时或若螨密度高于15头时,加州新小绥螨的捕食量显著高于拟长毛钝绥螨。两种捕食螨对朱砂叶螨3种螨态的功能反应均为HollingⅡ型,加州新小绥螨对朱砂叶螨3种螨态控制能力(a'/Th值)均强于拟长毛钝绥螨。加州新小绥螨对朱砂叶螨卵、若螨的理论最大捕食量分别比拟长毛钝绥螨的高出35.0%、37.1%;对幼螨的理论最大捕食量仅比拟长毛钝绥螨低8.0%。     

提高花粉饲养伪钝绥螨繁殖力的试验

单独用苹果花粉喂养伪钝绥螨,其后代生活力降低。本文报道在苹果花粉中分别添加30％王浆水、30％蜂蜜水饲养伪钝绥螨,或用苹果花粉和朱砂叶螨交替喂食。结果表明,其后代成螨性比较单独用苹果花粉喂食者均有提高,雌成螨自食其卵现象基本消除。其中以苹果花粉和朱砂叶螨交替供食者效果最好,后代成活率明显提高。以苹果花粉为主食料,定期添加朱砂叶螨,5周后伪钝绥螨的增殖倍数与完全取食朱砂叶螨者相近。     

Impact of intraguild predation and lambda-cyhalothrin on predation efficacy of three acarophagous predators

This laboratory study reports the interaction of three predators found in commercial apple orchards in Quebec, Hyaliodes vitripennis (Say) (Hemiptera: Miridae), Harmonia axyridis Pallas (Coleoptera: Coccinellidae) and Amblyseius fallacis (Garman) (Acarina: Phytoseiidae). First, intraguild predation between H vitripennis and the two other predators was characterized in the absence and presence of their extraguild prey, Tetranychus urticae Koch. The results showed an asymmetrical interaction in favour of the larger predator and the levels of intraguild predation were weak for the two predatory combinations. Presence of the phytophagous mite reduced the intensity of intraguild predation in the predatory combination of H axyridis and H vitripennis. Second, the effects of intraguild predation and the application of lambda-cyhalothrin on predation efficacy of the predators were evaluated. The application of the insecticide reduced prey consumption of H vitripennis and H axyridis but did not affect that of A fallacis. Combination of predators and an insecticide application resulted in two different situations depending on the species involved: a reduced predation efficacy for the combination of H vitripennis and H axyridis due to a knockdown effect caused by the insecticide, and no effect on T urticae consumption for H vitripennis and A fallacis. It is suggested that an integrated pest management program based on H vitripennis, A fallacis and lambda-cyhalothrin may be evaluated to repress phytophagous mites in Quebec orchards.     

The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae)

A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S-kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias-Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow-acting insecticide, so toxicity data were recorded 7 days post-treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6x the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S-kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes.     

食物链网络DNA跟踪技术研究进展

近年来,DNA分子跟踪食物链技术发展迅速并逐渐成为脊椎动物与无脊椎动物食物链研究的新型模式。该技术通过对捕食者肠道或粪便中DNA的鉴定,判别所取食的猎物种类,其主要流程包括PCR引物设计、交叉特异性验证、室内测试、田间样本采集与保存、野外标本测试与结果分析等。该文介绍了食物链DNA跟踪技术的发展历程,对捕食者猎物结构、被捕食者天敌种类与猎物可检测时间等三个主要问题进行综述,并提出该技术的局限性与未来发展的方向。     

伪钝绥螨的花粉饲养研究

在饲养伪钝绥螨的10种植物花粉中,核桃、洋槐、贴梗海棠、仙人球、迎春和卷心菜等可使其取食并完成发育,前4种还可使其产卵。花粉粒的外部形态结构,是影响该螨能否取食的重要因素之一。用桃、苹果花粉饲养伪钝绥螨,对其F_1代生活力有明显的不良影响。取食桃花粉的F_1代,幼螨间相互残杀,并取食未孵化的卵,使成活率降低。取食苹果花粉的F_1代可正常完成发育,但成螨性比降低,产卵时自食其卵。试验表明,单纯喂食桃或苹果花粉难以进行伪钝绥螨的累代饲养。     

The use of ecotoxicological risk assessment in deriving maximum acceptable half-lives of pesticides

Approaches in ecological risk assessment are usually based on estimating the probability that organisms will be exposed to environmental concentrations of chemicals greater than some toxicological criterion (LC₅₀, NOEC). Following this approach, quality standards for persistent chemicals in soil can be derived. For readily degradable chemicals emitted at intervals, the ecological risk can be related to the time taken for the chemical concentration to fall to a level causing no effect on most, e.g. 95%, of the species. A formula is derived for the maximum acceptable half-life, assuming a log–logistic distribution of species susceptibilities and a simple exponential decay of the chemical. It is also assumed that the pesticide is distributed homogeneously through the top 20 cm of the soil. A numerical example is elaborated for carbofuran, demonstrating that for a recommended dose applied to soil, the maximum half-life should be 47 days, if the ecotoxicological protection level is to be reached within one year after a single application. This estimate may vary between 35 and 61 days, depending on the margins of uncertainty attached to ecotoxicological data. Complete recovery not only includes the disappearance of the chemical but also the recolonization of treated soils. The half-life condition derived in this paper should therefore be considered as a minimum requirement.     

茶毒蛾步甲研究初报

茶毒蛾步甲的成、幼虫是茶毒蛾的主要捕食性天敌。一年两代,世代重叠,以成虫越冬,雌成虫寿命246—540天。一头幼虫一生能捕食3—6龄的茶毒幼虫33.2头,一头成虫在茶毒蛾一个世代中可捕食959头茶毒蛾幼虫。成虫在活动期能忍受饥饿55天,幼虫有相互残食习性。     

蠋蝽猎物—黏虫的室内种群复壮

猎物的质量直接决定了天敌的质量和饲养规模。蠋蝽是一种重要的捕食性天敌,其若虫和成虫对鳞翅目害虫幼虫均有较强的捕食能力。目前蠋蝽主要依靠黏虫来饲养。但在长期室内饲养过程中黏虫种群出现衰退现象,进而制约了蠋蝽规模化繁育。本文旨在研究黏虫种群复壮措施,为蠋蝽的规模化繁育提供技术支撑。为此,采用回接自然寄主和室内与室外种群杂交的方式评价了黏虫的种群复壮效果。结果表明,回接自然寄主玉米叶后黏虫的幼虫发育历期(18.03 d)较人工饲料饲养组(21.26 d)显著缩短,蛹重(369.00 mg)和成虫产卵量(770.88粒/雌)显著高于人工饲料饲养组(323.56 mg, 532.73粒/雌),但二者的蛹历期和成虫寿命无显著差异。杂交试验结果表明,4种交配方式产生的F₁代产卵前期、雌雄成虫寿命及其子代幼虫和蛹的发育历期无显著差异,但产卵期、产卵量及蛹重存在差异。其中以田间雌性×田间雄性(YF×YM)组合的产卵期最长(8.07 d)和产卵量最高(938.77粒/雌),而以田间雌性×室内雄性(YF×EM)组合的蛹最重(354.59 mg)。这些结果显示,通过回接自然寄主和室内与室...     

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.