Daily consumption and predation rate of different<Emphasis Type="Italic">Stethorus punctillum</Emphasis> instars feeding on<Emphasis Type="Italic">Tetranychus urticae</Emphasis>

Laboratory experiments were conducted to evaluate the prey stage preference and the daily consumption of each stage of the coccinellid predatorStethorus punctillum Weise (Coleoptera: Coccinellidae) feeding on the two-spotted spider miteTetranychus urticae (Koch) (Acari: Tetranychidae). Groups of different life stages of the prey were offered (eggs, larvae, nymphs and adults). The prey preference varied with the stage ofS. punctillum. First larval instars had no significant preference among theT. urticae stages offered. Second larval instars consumed significantly more spider mite larvae in comparison with nymphs. In contrast, third larval instars indicated a strong preference for mite eggs. Significantly fewerT. urticae larvae were consumed by the fourth larval instars ofS. punctillum, in comparison with the three other mite stages. Finally, adult predators consumed significantly more mite eggs than the other stages offered. This preferential trend was similar for all adults tested, whether during the pre-oviposition or the oviposition period. http://www.phytoparasitica.org posting Feb. 17, 2004.     

Insecticide resistance management and integrated mite management in orchards: can they coexist?

At the core of an integrated pest management program for Pennsylvanian apple orchards is an integrated mite management program that is based on a natural enemy, the coccinellid Stethorus punctum punctum (LeConte). The program relies upon the principles of ecological selectivity (e.g. chemical selection, timing, dose and method of application) for the organophosphate and carbamate insecticides. During the last 20 years the tufted apple bud moth (TABM), Platynota idaeusalis (Walker), a direct pest of apple, has developed resistance to these two chemical classes. In an effort to address this growing resistance problem, an intensive research program was initiated in 1986 on how to manage insecticide resistance in TABM while preserving the integrity of the integrated mite management program. One aspect of this research program is the investigation of biochemical and genetic approaches to resistance, including an analysis of detoxification mechanisms, effects of host plant allelochemistry on resistance and detoxification enzyme activities, reversion, gene flow and the isolation and characterization of a gene for glutathione transferase from TABM. Management approaches that have been developed and successfully implemented include pheromone mating disruption, parasitoids, ground-cover management including insecticides, Bacillus thuringiensis Berl. products and insect growth regulators. Resistance management options for TABM are presented. ©1997 SCI     

龟纹瓢虫对玉米蚜的捕食作用研究

在实验室条件下,测定了不同龄期龟纹瓢虫幼虫及雌雄成虫对玉米蚜的捕食作用.结果表明,龟纹瓢虫对玉米蚜的捕食作用在一定的空间范围内受其自身密度及猎物密度制约,相互间存在干扰.模拟后的各干扰反应方程经x2检验,其理论值与观察值差异不显著.说明龟纹瓢虫对玉米蚜具有很好的捕食控制作用,应注意保护玉米田间龟纹瓢虫.     

双尾新小绥螨对烟粉虱和土耳其斯坦叶螨的捕食选择性

为了明确双尾新小绥螨Neoseiulus bicaudus Wainstein对不同密度下烟粉虱Bemisia tabaci（Gennadius）和土耳其斯坦叶螨Tetranychus turkestani（Ugarov&Nikolskii）的捕食选择性,在实验室条件下,测定24 h内双尾新小绥螨对不同比例下猎物的捕食情况（烟粉虱和土耳其斯坦叶螨数量比为20：10、15：10、10：10、10：15、10：20和10：40）。结果表明双尾新小绥螨雌成螨对猎物的捕食量随猎物数量的升高而增加,其中对土耳其斯坦叶螨幼螨的捕食量最高。双尾新小绥螨除对烟粉虱1龄若虫和叶螨卵在10：10的相同密度下选择指数无差异外,其他各密度下,双尾新小绥螨对土耳其斯坦叶螨的选择性均显著高于烟粉虱。当烟粉虱和土耳其斯坦叶螨同时发生时,双尾新小绥螨对土耳其斯坦叶螨的选择性高于烟粉虱,对土耳其斯坦叶螨控制效果更好。     

解除生殖滞育的巴氏新小绥螨捕食能力

巴氏新小绥螨Neoseiulus barkeri是极具应用潜力的捕食螨,在农业生产中,广泛应用于防治多种害螨和小型吸汁性害虫。由于活体天敌的特殊性,如何保障储运期间巴氏新小绥螨的存活率和捕食能力的稳定性,是目前捕食螨产品高效安全应用的难题之一,进行诱导生殖滞育,是延长捕食螨货架期的有效途径。本文采用选择系数和Holling圆盘方程测试方法,研究了解除生殖滞育（以下简称滞育）的巴氏新小绥螨的选择取食作用和捕食功能,结果如下：（1）普通品系、滞育解除品系、滞育品系的巴氏新小绥螨对腐食酪螨不同螨态的捕食选择性和被食比例呈现出基本一致的趋势,表现出强烈的选择性;三个品系的巴氏新小绥螨均对猎物幼螨表现出嗜食性,其选择系数从高到低为幼螨,卵,若螨,成螨;但也表现出一定的差异性,普通品系与滞育解除品系对猎物的卵和幼螨均表现为嗜食性,滞育品系的巴氏新小绥螨仅对猎物的幼螨表现为嗜食性。（2）三个品系的捕食功能曲线均符合HollingⅡ型圆盘方程;滞育解除后巴氏新小绥螨能快速恢复生长发育和捕食能力,普通品系、滞育品系、滞育解除品系的巴氏新小绥螨对猎物腐食酪螨的攻击系数a分别为0.6761、0.2731、0...     

稻虱缨小蜂的功能反应和干扰反应

稻虱缨小蜂Anagrus nilaparvatae对寄主白背飞虱Sogatella furcifera卵密度的功能反应为负加速曲线,其方程为:N_a=N{1-exp[-0.2121/(1+0.02935)]},其中N为寄主密度,N_a为日每雌蜂寄生寄主数。瞬时攻击率a为1.2121/天,处理时间Th为0.0242天,理论上每雌蜂日最高寄生卵数为41.3粒。第1天产出卵率(y)随寄主密度(N)变化方程为y=0.0342N~(0.7223)。搜寻效应a与寄生蜂自身密度P的关系方程为a=1.0913P(-1.1717),寄生蜂个体间存在明显的相互干扰效应。     

Prey consumption rates and compatibility with pesticides of four predatory mites from the family Phytoseiidae attacking Thrips palmi Karny (Thysanoptera: Thripidae)

BACKGROUND: Predatory mites (Amblyseius swirskii Athias‐Henriot, Typhlodromips montdorensis Schicha, Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans Berlese) were investigated for their potential to act as control agents for Thrips palmi Karny. Prey consumption rates and compatibility with pesticides were assessed. RESULTS: Second‐instar larvae were the preferred life stage. Typhlodromips montdorensis consumed the most larvae (2.8) and also an average of 1.2 adult T. palmi per 5 day period. Both 24 and 48 h assessments following application of abamectin, spinosad and imazalil demonstrated mortality of predatory mites (across all species), which was significantly higher than with the other treatments (P < 0.001). Spraying with pymetrozine did not provide any increased mortality when compared with the water control. Application of thiacloprid proved detrimental only to I. degenerans. Following indirect exposure of predatory mites to pymetrozine and imazalil, no significant differences in mite mortality were obtained. Indirect exposure to spinosad was identified as the most detrimental treatment (P < 0.001) to all mites. Abamectin also proved detrimental, with only T. montdorensis showing any potential tolerance. CONCLUSION: All predatory mites investigated offer potential for controlling T. palmi. Compatibility with chemicals varied between the mites. The potential of incorporating the mites into eradication strategies for T. palmi is discussed. Copyright © 2012 Society of Chemical Industry     

七星瓢虫对草地贪夜蛾低龄幼虫的捕食能力评价

为了评估七星瓢虫Coccinella septempunctata对重大入侵害虫草地贪夜蛾Spodoptera frugiperda（J.E.Smith）的防控效果,本试验在室内条件下开展了七星瓢虫对草地贪夜蛾1龄、2龄幼虫的捕食功能反应和种内干扰研究。结果表明：七星瓢虫对草地贪夜蛾幼虫的捕食功能反应均符合HollingⅡ模型,七星瓢虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为233.100头、1.204和0.103 h;对草地贪夜蛾2龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为41.220头、1.075和0.582 h。七星瓢虫的搜寻效应随猎物密度的增加而逐渐降低。七星瓢虫对草地贪夜蛾的捕食作用受到较强的种内干扰。试验证明七星瓢虫对草地贪夜蛾具有较好的控害效果,可用于对草地贪夜蛾的防控实践。     

东亚小花蝽对草地贪夜蛾幼虫的捕食效应

为探明东亚小花蝽Orius sauteri对草地贪夜蛾Spodoptera frugiperda幼虫的控制潜力,开展了不同温度下东亚小花蝽对不同龄期和密度的草地贪夜蛾幼虫的捕食功能反应与干扰作用研究。结果表明:当东亚小花蝽捕食1龄或2龄草地贪夜蛾幼虫时,其捕食功能反应与HollingⅡ模型拟合度较好。东亚小花蝽对草地贪夜蛾1龄幼虫在20℃、25℃和28℃下的瞬时攻击率分别为0.772 4、1.090 0、0.673 6,处理单头幼虫的时间为0.174 9、0.173 7、0.295 5 d,对2龄幼虫,在20℃、25℃和28℃下的瞬时攻击率分别为0.794 5、1.153 8、0.392 2,处理单头幼虫的时间为0.218 9、0.805 6、0.696 0 d;东亚小花蝽对草地贪夜蛾幼虫的捕食量表现出随着猎物密度增加而上升,随自身密度的增加而下降的趋势;同一温度下,东亚小花蝽对1龄幼虫的日均捕食量和寻找效应均高于2龄幼虫,寻找效应与猎物密度成反比;东亚小花蝽对3龄和4龄草地贪夜蛾幼虫的日均捕食量为0;田间自然状态下东亚小花蝽对草地贪夜蛾幼虫的控制率为34.62%。     

异色瓢虫对草地贪夜蛾和禾谷缢管蚜的捕食功能反应及捕食选择性研究

为探究入侵害虫草地贪夜蛾Spodoptera frugiperda与本地害虫禾谷缢管蚜Rhopalosiphum padi同时存在时,异色瓢虫Harmonia axyridis对入侵害虫草地贪夜蛾的防控效果,本研究开展了异色瓢虫成虫及4龄幼虫对草地贪夜蛾2龄幼虫、禾谷缢管蚜2龄若虫的捕食功能反应、搜寻效应、捕食选择性试验。结果表明,异色瓢虫对草地贪夜蛾、禾谷缢管蚜的捕食功能反应均符合HollingⅡ模型方程,其日捕食量随物密度的增加而增加,搜寻效应均随猎物密度的增加而逐渐降低;异色瓢虫成虫对草地贪夜蛾2龄幼虫、禾谷缢管蚜2龄若虫的控害效能分别为221.88头和343.01头,其4龄幼虫对草地贪夜蛾2龄幼虫、禾谷缢管蚜2龄若虫的控害效能分别为140.88头和210.93头。异色瓢虫对草地贪夜蛾和禾谷缢管蚜具有较好的控害能力,其成虫对两种害虫的防控效果优于其4龄幼虫,且异色瓢虫对禾谷缢管蚜的捕食选择性强于草地贪夜蛾。     

不同灌溉方式对苹果园土壤水分动态、耗水量和产量的影响

为探讨不同灌溉方式对苹果园土壤含水率、生育期耗水量、产量及水分利用效率的影响,于2005年4～11月在密云水库上游地区新城子蔡家甸有机苹果基地布设了3种灌溉方式(管灌、滴灌和微喷灌)及对照(不灌溉)共4个处理、3个重复的对比试验.分别在苹果树开花期、枝条速长期、成熟期和封冻前灌水,依据不同灌溉方式的灌溉效率以及田间土壤实际含水率等因素确定灌水量.结果表明:(1)在3种灌溉方式处理中,微喷灌、滴灌处理的0～60 cm土层土壤含水率较高,入渗深度在80 cm以内,未产生水分深层渗漏.管灌向下入渗深度大于微喷灌和滴灌,达到120 cm.(2)在整个生育期内,微喷灌和滴灌处理比管灌节约灌水量分别是31.99%和49.83%;微喷灌和滴灌条件下果园耗水量较管灌分别减少11.52%和12.49%.(3)从产量来看,微喷灌、滴灌、管灌产量分别比对照高25.74%、9.99%和0.78%;微喷灌产量达到51 000 kg/hm2;其水分利用效率最高且达到9.288 kg/m3.总体看来,微喷灌是相对较好的节水增效灌溉方式,值得在果园灌溉中应用.     

不同刻芽处理对苹果枝条内源激素和发芽成枝的影响

为揭示苹果枝条内源激素动态特征与发芽成枝对不同刻芽处理的差异性反应,探明不同刻芽处理条件下苹果内源激素调控枝条芽眼萌发的机制,以3 a生‘中秋王’苹果的1 a生枝条为材料,设全刻芽(T1)、基部刻芽(T2)、中部刻芽(T3)、上部刻芽(T4)4个处理,以不做刻芽处理的枝条为对照(CK),研究其内源激素含量与枝条萌发成枝的关系。结果表明,刻芽处理可显著提高中秋王苹果枝条刻芽部位的萌芽率、成枝力(P<0.05),萌芽率和成枝率整体分别较CK提高了9.3%和171.7%。枝条萌芽率与成枝力呈极显著正相关(P<0.01),相关系数为0.643,与长枝率、短枝率呈显著正相关和负相关(P<0.05),相关系数分别为0.594和-0.613。刻芽后,枝条被刻部分芽中IAA和GA₃含量最高,分别较CK提高26.5%和40.3%,而ABA含量较CK降低了66.1%。刻芽后7 d枝条芽中ZT/IAA比值和刻芽后14 d ZR/GA₃比值与萌芽率负相关性最好,相关系数分别为-0.731和-0.719,说明这两个指标对枝条萌芽的调控作用最大。     

绿盲蝽对花期葎草的产卵选择性

前期研究发现,葎草进入盛花期后对绿盲蝽Apolygus lucorum成虫吸引力明显增强,植株上绿盲蝽成虫种群密度快速上升。2011年和2016年,研究了绿盲蝽成虫对初花期与盛花期葎草的产卵选择性。结果发现:盛花期葎草植株上的绿盲蝽成虫密度和卵密度显著高于初花期。绿盲蝽卵主要集中产在花上,而幼芽、嫩茎和叶柄上落卵量较低。同时,在盛花期葎草上,绿盲蝽若虫种群密度以及高龄若虫比例显著偏高。本研究进一步证实了绿盲蝽成虫对盛花期葎草的产卵偏好习性。     

不同种源沙柳(Salix psammophila)苗木蒸腾耗水特性的研究

于2004年生长季节利用BP3400精密天平等仪器,在人工模拟干旱的条件下,对5个种源沙柳苗木的连日耗水量和耗水速率日变化规律进行观测。结果表明:5个种源沙柳的连日耗水量呈现一致的波动递减趋势;耗水速率日变化均呈明显的"单峰型"曲线,峰值出现在12:00-14:00,随干旱胁迫的加剧,民勤和榆林种源提前到10:00-14:00。白天平均耗水速率和最大耗水速率均是适宜水分>中度干旱>严重干旱。民勤种源在整个干旱胁迫过程中总耗水量最小为1876.9g,其次是达拉特种源(1972.8g)和盐池种源(2001.8g),耗水量最大是乌审旗(2200.6g)和榆林种源(2112.9g)。沙柳各种源最大耗水速率与白天平均耗水速率的比值非常接近,平均为1.56,根据这一比例关系,在对沙柳的最大耗水速率进行测定后,可以推算出其白天的平均耗水速率,并进一步推算白天(或整天)的耗水量。     

阶段性组合猎物饲养南方小花蝽的效果评价

为探讨阶段性组合猎物在饲养南方小花蝽过程中的适合性,本研究用蚕豆蚜、阶段性组合猎物(1豆蚜和二斑叶螨)分别饲喂南方小花蝽。研究发现,饲喂蚕豆蚜的成虫获得率最低为34.2%;连续2代饲喂阶段性组合猎物与混合猎物的成虫获得率均在80%左右。用阶段性组合猎物饲养的南方小花蝽第1代和第2代的未成熟期(15.30和15.28 d)都略长于混合猎物的14.71 d,但明显短于蚕豆蚜饲养的21.48 d。阶段性组合猎物饲养南方小花蝽连续两代的净生殖率(27.85、40.13)、内禀增长率(0.16、0.18)与取食混合猎物时的净生殖率(31.38)、内禀增长率(0.16)相差不大,均明显高于饲喂蚕豆蚜时的净生殖率(4.27)、内禀增长率(0.06),能够很好地满足南方小花蝽种群增长的营养需求。     

稻虱缨小蜂对褐稻虱寄生作用函数的研究

稻虱缨小蜂 Anagrus nilaparvatae 是褐稻虱 Nilaparvata lugens 卵期的重要天敌。褐虱缨小蜂与褐稻虱之间的相互作用,构成褐稻虱种群生命系统中的一个亚系统,在研究其数量控制中有必要分别进行研究。Lotka(1925),Volterra(1926),Thompson(1924)等首先提出了寄生者——寄主(或捕食者一猎物)模型。Nicholson(1933)和 Nicholson and Bailey(1935)进一步提出了寄生(捕食)作用函数的模式,为研究寄生者——寄主(或捕食者——猎物)的相互作用提供了一个基础。作为寄生者作用后的存活率,此函数可看成昆虫种群生     

8种杀螨剂对马铃薯朱砂叶螨的防治效果

为了筛选在西北旱作区针对马铃薯朱砂叶螨的最佳防治药剂, 选择了8种杀螨剂进行两年的田间药效试验。结果表明, 24%螺螨酯悬浮剂(SC)处理下的马铃薯单株块茎数最高, 螨株率最低, 并且叶片SPAD值及光合参数值最高, 8种药剂中, 24%螺螨酯SC、43%联苯肼酯SC、2%阿维菌素SC、11%乙螨唑SC和73%炔螨特乳油(EC)对马铃薯朱砂叶螨防效高于80%, 可作为防治马铃薯朱砂叶螨的药剂。     

海岛小花蝽对茶黄蓟马捕食作用及选择偏好

为评价海岛小花蝽Orius maxidentex Ghauri对茶黄蓟马Scirtothrips dorsalisHood的控害潜能,在室内测定了海岛小花蝽对茶黄蓟马的捕食能力和捕食选择性。结果表明：海岛小花蝽1龄若虫不取食茶黄蓟马,2龄若虫可取食少量的茶黄蓟马1龄和2龄若虫,3龄若虫至成虫均可取食茶黄蓟马各龄若虫及成虫;海岛小花蝽3龄若虫至成虫对茶黄蓟马2龄若虫和成虫的捕食量由大到小均依次为5龄若虫,成虫,4龄若虫,3龄若虫,其中5龄若虫最大,取食量分别为茶黄蓟马2龄若虫31.60头/d、成虫30.80头/d;海岛小花蝽3龄若虫至成虫对茶黄蓟马的捕食作用均符合Holling Ⅱ功能反应模型,捕食量均随着猎物密度的增加而升高,搜寻效应均随着猎物密度增加而下降;海岛小花蝽对茶黄蓟马干扰反应符合Hasse Ⅱ模型方程,当茶黄蓟马密度不变时,随着海岛小花蝽自身密度的增加,单头捕食量逐渐降低;海岛小花蝽3龄若虫至成虫均对茶黄蓟马1龄若虫的喜好指数Ci＞0,对茶黄蓟马成虫喜好指数Ci＜0,表明其对茶黄蓟马低龄若虫有较高的捕食偏好。本研究结果表明海岛小花蝽对茶黄蓟马具有较好的防控潜能。     

半闭弯尾姬蜂的寄主选择性及寄生对寄主发育和取食的影响

在24℃下研究了半闭弯尾姬蜂寄生对寄主幼虫龄期的选择性及对寄主生长发育、取食量的影响。结果表明，该蜂能寄生小菜蛾2-4龄的幼虫，但当2-4龄幼虫同时存在时，偏爱寄生2、3龄幼虫，对2、3、4龄幼虫的选择系数分别为0．37、0．44、0．19。该蜂对4龄幼虫的寄生能力随寄主日龄增大而下降。2-4龄小菜蛾幼虫被寄生后，总发育历期与预蛹期都比未被寄生的显著延长。当小菜蛾幼虫在2龄初被寄生后，总取食量比未被寄生的显著减少；但当幼虫在3、4龄初被寄生后，各龄的取食量与未被寄生的差异不显著。     

Fitness costs associated with milbemectin resistance in the two-spotted spider mite Tetranychus urticae

The two-spotted spider mite Tetranychus urticae Koch is one of the most important pests of a wide range of crops worldwide. Its control is still largely based on the use of acaricides. However, due to its short life-cycle, high fecundity and arrhenotokous reproduction, it is able to develop resistance to these compounds very rapidly. Preliminary studies for milbemectin resistance in T. urticae showed that, under laboratory conditions, such resistance was unstable in the absence of a selection pressure. The aim of this study was to evaluate the possible fitness costs associated with milbemectin resistance in T. urticae. Comparison of biological traits between resistant and susceptible strains indicated the occurrence of fitness costs associated with milbemectin resistance. The resistant strain showed a longer juvenile development period for females, lower fecundity and a higher proportion of males among the progeny. The figures for net reproductive rate (R ₀), intrinsic rate of natural increase (r _m) and finite rate of increase (λ) were higher in the susceptible strain. The instability of milbemectin resistance can be exploited in resistance management programmes.