二斑叶螨的检疫重要性

二斑叶螨的检疫重要性程立生（华南热带作物学院植保系）１二斑叶螨（ＴｅｔｒａｎｙｃｈｕｓｕｒｔｉｃａｅＫｏｃｈ）是一种世界性的大害螨，但在我国仅局部分布于台湾岛、北京市和天水市郊。据报道，二斑叶螨在国外主要分布于美国北部、英国、土耳其、地中海沿岸、南非...     

二斑叶螨与朱砂叶螨种间竞争的研究

１９９７年４～６月对二斑叶螨与朱砂叶螨的种间竞争进行了研究。结果表明,无论单种种群还是混合种群,二斑叶螨的活动虫态和雌成虫的ｒｍ均高于朱砂叶螨。二斑叶螨具有更强的种间竞争能力,在该螨发生地极有可能取代朱砂叶螨而成为农田中的优势种。     

智利小植绥螨防治大棚草莓二斑叶螨试验初报

二斑叶螨是上海地区温室大棚草莓上的重要害虫之一。研究了释放智利小植绥螨防治大棚草莓上二斑叶螨的效果。结果表明,释放智利小植绥螨对草莓二斑叶螨有显著抑制作用,防治效果十分明显。以300头/m2的释放量释放智利小植绥螨14 d后,防效可达99.66%,比5%噻螨酮EC 2 000倍液处理高33.45百分点,释放量为100头/m214 d后的防效也达到了60.24%。且智利小植绥螨具有较大的探索能力,在释放区将害螨捕食完毕后,能迅速扩散到邻近的有害螨的区域继续捕食。     

花生二斑叶螨的发生与防治

二斑叶螨又称白蜘蛛,主要危害苹果、梨及豆科植物。l999年之前在河南省信阳市花生上只是零星地块发生,2001年7～8月间田间调查,该螨已经在该市花生产区15个乡、镇普遍发生,受害严重。危害盛期螨蔸率达90％～100％,单叶有螨15～28头,对花生产量影响很大。     

阿维菌素生物农药防治二斑叶螨药效试验

７０５１杀虫素、集琦虫螨克均属阿维菌素系列生物农药,其主要特点是杀虫、杀螨、广谱、高效、低毒、安全、不易使害虫产生抗性。针对二斑叶螨寄主范围广、食性杂、繁殖速度快、抗药性强的特点,我们特选用以上两种生物农药进行试验、示范,现将结果整理如下。１材料和方...     

利用长毛钝绥螨控制冬瓜上二斑叶螨研究

冬瓜是南方主要蔬菜品种之一，遭受二斑叶螨Ｔｅｔｒａｎｙｃｎｕｓ ｕｒｔｉｃａｅ（Ｋｏｃｈ）严重危害。作者在冬瓜生长五叶期每株释放长毛钝绥螨Ａｍｂｌｙｓｅｉｕｓ ｌｏｎｇｉｓｐｉｎｏｓｕｓ３０只，１周后二斑叶螨下降９１．５％。并能控制叶螨的增殖直至收获期。室内对长毛钝绥螨与二斑叶螨间的相互关系进行探讨。     

阿维菌素与植物精油复配对朱砂叶螨杀螨的增效作用研究

为了得到对朱砂叶螨(Tetranychus cinnabarinus)具有较好杀螨活性的植物精油与阿维菌素复配配方,并为杀螨剂开发应用提供指导,本研究采用喷雾法测定了柠檬草、广藿香、山鸡椒、亚洲薄荷植物精油及阿维菌素对朱砂叶螨的毒力,分别采用共毒因子法和共毒系数法评价了山鸡椒和亚洲薄荷精油对阿维菌素的增效作用和复配最佳...     

联合应用智利小植绥螨与丁氟螨酯防治草莓二斑叶螨

本文研究了新型杀螨剂丁氟螨酯对叶螨天敌智利小植绥螨的毒性、对智利小植绥螨繁殖的影响以及两者联合应用对草莓二斑叶螨的防治效果。结果表明,丁氟螨酯对智利小植绥螨的毒性很低,即使在400 mg/L的高浓度下,智利小植绥螨的死亡率仍然低于35%,对雌、雄成螨的LC₅₀分别为669.4 mg/L和456.4 mg/L。施用丁氟螨酯后,丁氟螨酯对智利小植绥螨成螨存活率影响无显著差异。田间试验表明单独使用智利小植绥螨和联合使用智利小植绥螨与丁氟螨酯,两周内对草莓二斑叶螨的防治效果都在90%以上,明显好于单独使用丁氟螨酯。相比于单独使用智利小植绥螨的生物防治区,联合防治区的防治效果更好,28 d时仍高于95%。因此,智利小植绥螨与丁氟螨酯联合应用防治草莓叶螨效果更佳。     

二斑叶螨对常用杀螨剂的抗药性测定

采用玻片浸渍法 ,测定了二斑叶螨Tetranychus urticae Koch山东寿光种群 (R1)和山东烟台种群 (R2 )对常用杀螨杀虫剂的抗性 ,与山东泰安相对敏感种群 (S)相比 ,对哒螨灵、高效氯氟氰菊酯和甲氰菊酯 3种药剂的抗性 ,R1分别达 6.67、6.33和 10.36倍 ,R2分别达 26.56、15.4 5和 31.30倍 ,R1和 R2对上述 3种药剂均产生了较高水平的抗药性。另外,R1、R2种群对其它药剂也均表现出了不同程度的抗性现象。     

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）。     

巴氏新小绥螨对二斑叶螨混合抗性品系和敏感品系的捕食功能

为明确巴氏新小绥螨对二斑叶螨混合抗性品系（R）和敏感品系（S）捕食功能的差异,在RH（75±5）%、光周期16L：8D条件下,设置16、20、24、28和32 ℃5个温度梯度,研究了巴氏新小绥螨对两个品系二斑叶螨各螨态的捕食效能。结果表明,巴氏新小绥螨对两个品系二斑叶螨各螨态的捕食功能反应均属于HollingⅡ型。16～28 ℃范围内,对二者的攻击系数、捕食能力、最大日捕食量均随温度升高而增加,处理时间则缩短。28 ℃时对雌成螨、若螨和卵捕食量最高,R品系为7.5700头、14.4928头和16.0256粒,S品系为7.9114头、18.3150头和20.1207粒;处理时间最短,R品系为0.1321、0.0690和0.0624 d,S品系为0.1264、0.0546和0.0497 d,温度达到32 ℃时,捕食量下降。在同一温度下,对S品系的捕食能力显著大于R品系（P<0.05）。说明巴氏新小绥螨对二斑叶螨混合抗性品系有一定的拒食作用,这与二斑叶螨R品系在长期药剂选择压力下体壁硬化有关。因此,田间防治二斑叶螨时要交替轮换使用化学农药,保护天敌实现生物防治和化学防治相协调的同时,避免或延缓其产生抗药性,从而更好地实现二斑叶螨的综合防控。     

增效剂与常规药剂混用对抗性二点叶螨增效作用的研究

供试二点叶螨为抗氧乐果、甲氰菊酯、螨死净和抗螨嗪菊酯混剂种群 ,用 4种增效剂分别与氧乐果、甲氰菊酯、螨死净、螨嗪菊酯混用研究其增效作用。结果表明 :增效磷 (SV₁)对甲氰菊酯、氧乐果、螨死净、螨嗪菊酯的增效作用最明显 ,增效倍数分别为23.33、17.26、7.09、9.42 ;其次是八氯二丙醚 (S₂)和增效醚 (Pb) ,全能增效剂 (ARS)对4种药剂增效作用最差。田间药效试验结果表明 :增效剂SV₁和S₂ 与氧乐果、甲氰菊酯、螨死净混用 ,对苹果和豇豆上的二点螨均有增效作用。     

二斑叶螨实验种群生命表的组建与分析

组建并分析了辣椒上二斑叶螨实验种群生命表。在 23℃恒温条件下 ,种群的内禀增长力r_m 为0.1510,周限增长率λ为1.1630/d ,净增殖率R_o为29.1497代 ,平均世代周期T为 22.3291d ,种群增长一倍需要的时间t为4.59d。在稳定种群年龄分布中 ,未成熟期占总量的88.9444% ,成熟期占11.0506%。     

15种常用杀虫剂对二斑叶螨的室内药效对比试验

本文采用FAO推荐的玻片浸渍法,选用15种常用杀虫剂的最大登记剂量对二斑叶螨敏感型种群和抗性种群进行了药效对比试验研究。结果表明:施药后观察,哒螨·矿物油、阿维·哒螨灵、阿维菌素、阿维·灭幼脲、阿维·毒死蜱、啶虫脒对敏感型二斑叶螨的速效性防效较好;而炔螨特、桉油精和苦参碱对抗性二斑叶螨的防效较强。     

Biochemical analysis of a chlorfenapyr-selected resistant strain of Tetranychus urticae Koch

Tetranychus urticae Koch has recently developed resistance to chlorfenapyr in Australia and Japan, but no attempt has yet been made to describe the biochemical mechanisms involved in chlorfenapyr resistance. In this study a laboratory-selected chlorfenapyr-resistant strain was investigated. Resistance to chlorfenapyr was associated with a strong increase in esterase activity and P450 mono-oxygenase (MO) activity but a decrease in 3,3',5,5'-tetramethylbenzidine (TMBZ) peroxidation activity. Differences in esterase activities between susceptible and resistant strains increased with increasing carbon number of the aliphatic side-chain of the nitrophenol substrate. A 4.4-fold increase in the O-deethylation of 7-ethoxy-4-trifluoromethyl coumarin (7-EFC) mediated by P450 MOs was detected. Remarkably, the resistant strain showed only half of the total TMBZ peroxidation activity found in the susceptible strain. The activity of these enzymes was further determined on different crosses and back-crosses of both strains. Results indicated that activities correlated with chlorfenapyr susceptibility and could be considered as biochemical markers. Esterase isozymes of both strains and their crosses were separated with isoelectric focusing (IEF) and visualised after activity staining. It was clear that two distinct zones of enhanced esterase activity were present in the chlorfenapyr-resistant strain (EST 11, pI = 4.88 and EST 16, pI = 4.71). EST 11 was identified with inhibitors as a carboxylesterase. The relative presence and intensity of these esterase zones changed in the different crosses and could be seen as a marker for chlorfenapyr resistance. Glutathione-S-transferase and glucose-6-phosphate dehydrogenase activities were not significantly different between strains. A twofold decrease in TMBZ peroxidase activity in the resistant strain could reflect decreased activation of chlorfenapyr. On the basis of these results the involvement of P450 MOs and esterases in the activation and detoxification of chlorfenapyr in T. urticae is challenged and discussed.     

新型杀螨剂-乙唑螨腈对草莓二斑叶螨防效及安全性研究

以二斑叶螨为Tetranychus urticae Koch试虫,采用田间药效试验的方法,研究了乙唑螨腈等6种杀螨剂对二斑叶螨的田间防效及对草莓的安全性。以期为草莓二斑叶螨防控提供高效、安全的杀螨剂。结果表明:30%乙唑螨腈悬浮剂速效性与持效性最好,药后1d的防效为91.80%,14d防效为95.56%;20%丁氟螨酯悬浮剂和100g/L联苯菊酯乳油2种药剂的速效性较好,持效性较差,药后Id防效在83%-89%,药后14d的防效在27%~46%;43%联苯肼酯悬浮剂在药后3d的防效最高,达到87.87%;1.8%阿维菌素乳油在药后1~14d防效在36%-72%之间。73%炔螨特乳油在365mg/L浓度下对草莓叶片产生药害,其它药剂对草莓安全。     

Acaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two-spotted spider mite (Tetranychus urticae)

BACKGROUND: Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in the world. RESULTS: The chemical composition of the two oils was characterised by GC‐MS. The most abundant component in the Santolina africana (Jord. & Fourr) oil was terpinen‐4‐ol (54.96%), while thymol (61%) was prevalent in the Hertia cheirifolia (L.) oil. Mortality and fecundity were measured upon treatment with oil concentrations ranging from 0.07 to 6.75 mg L^?1 with a Potter spray tower. Mite mortality increased with oil concentration, with LC₅₀ values of 2.35 mg L^?1 for S. africana and 3.43 mg L^?1 for H. cheirifolia respectively. For both oils, a reduction in fecundity was observed at concentrations of 0.07, 0.09 and 0.29 mg L^?1. Artificial blends of constituents of oils were also prepared and tested with individual constituents missing from the mixture. The results showed that the presence of all constituents was necessary to equal the toxicity of the two natural oils. CONCLUSION: S. africana and H. cheirifolia oils can provide valuable acaricide activity with significantly lower LC₅₀ values. Thus, these oils cause important mortality and reduce the number of eggs laid by females. Copyright © 2012 Society of Chemical Industry     

Comparative toxicity of Rosmarinus officinalis L. essential oil and blends of its major constituents against Tetranychus urticae Koch (Acari: Tetranychidae) on two different host plants

Bioassays of Rosmarinus officinalis L. essential oil and blends of its major constituents were conducted using host-specific strains of the two-spotted spider mite, Tetranychus urticae Koch, on bean and tomato plants. Two constituents tested individually against a bean host strain and five constituents tested individually against a tomato host strain accounted for most of the toxicity of the natural oil. Other constituents were relatively inactive when tested individually. Toxicity of blends of selected constituents indicated a synergistic effect among the active and inactive constituents, with the presence of all constituents necessary to equal the toxicity of the natural oil.