褐飞虱对噻虫嗪和烯啶虫胺的抗性风险评估

采用稻茎浸渍法,测定了广州市本地褐飞虱种群对噻虫嗪和烯啶虫胺的室内毒力,评估褐飞虱对其的抗性风险。结果表明：广州本地褐飞虱种群对噻虫嗪和烯啶虫胺的LC50分别为02857mg/L和05022 mg/L,分别是敏感品系LC50的267倍和106倍,仍属敏感水平。室内抗性筛选结果表明：经过30代的连续筛选后,噻虫嗪的抗性上升82980倍,达到极高抗性水平,烯啶虫胺的抗性上升3170倍,达到中等抗性水平,表明褐飞虱对噻虫嗪和烯啶虫胺存在抗性风险的可能。根据试验结果,对褐飞虱噻虫嗪和烯啶虫胺抗性的预防治理提出了应用策略。     

褐飞虱和白背飞虱对几类杀虫剂的敏感性

为了科学用药和抗性治理提供理论基础, 采用稻茎浸渍法测定了2008年7月采自浙江省杭州市和宁波市褐飞虱 Nilaparvata lugens (Stål)种群对7种杀虫剂的抗药性及褐飞虱和白背飞虱Sogatella furcifera (Horváth)种群对16种杀虫剂的敏感性。褐飞虱抗药性测定结果表明, 与相对敏感品系相比, 杭州种群和宁波种群对吡虫啉的抗性倍数分别为479.0倍和366.1倍; 对氯噻啉的抗性倍数分别为81.1倍和50.9倍; 对噻虫嗪的抗性倍数分别为10.3倍和9.4倍; 对噻嗪酮和氟虫腈分别产生了5.0~8.6倍和15.8~17.0倍的抗药性; 对烯啶虫胺和啶虫脒的抗性倍数在3倍以下。两种稻飞虱对杀虫剂的敏感性测定结果表明: 噻虫嗪、噻嗪酮、烯啶虫胺和毒死蜱对褐飞虱和白背飞虱种群都具有较高的室内毒力。当田间褐飞虱和白背飞虱混合发生时, 可选用噻虫嗪、噻嗪酮、烯啶虫胺和毒死蜱进行防治, 不宜使用吡虫啉、氯噻啉和氟虫腈防治。     

广东稻区褐飞虱对烯啶虫胺和呋虫胺的敏感性测定

为了科学用药和抗性治理提供理论依据,在室内采用稻茎浸渍法测定了采自广东省广州、南雄、雷州、连州、海丰、怀集和大埔等7个地方田间褐飞虱种群对烯啶虫胺、呋虫胺的敏感性。试验结果表明:广东地区褐飞虱种群对烯啶虫胺的敏感性LC_(50)值为2.3187-7.1489mg/L,抗性倍数分别为4.93-15.21倍,南雄地区褐飞虱种群对烯啶虫胺仍处于敏感阶段;广州、海丰和雷州等3个地区褐飞虱对烯啶虫胺已产生低水平抗性,大埔、连州和怀集等3个地方褐飞虱已对烯啶虫胺产生中等水平抗性。广东地区褐飞虱种群对呋虫胺的敏感性LC_(50)值为3.6696-11.8093 mg/L,抗性倍数为26.21-84.35倍,表明广东省不同地区褐飞虱种群对呋虫胺均产生中等水平抗性。建议在防治褐飞虱时,对于低水平抗性的烯啶虫胺应轮用、混用,对中等水平抗性的呋虫胺应限制使用。     

褐飞虱抗药性研究现状

褐飞虱Nilaparvata lugens(Stal)对杀虫剂产生抗药性是其近年来暴发频繁的重要原因。文章综述国内外关于褐飞虱抗药性的研究成果,包括褐飞虱抗性测定方法、抗药性的发展、交互抗性、抗性遗传、抗性机理及抗性治理等。田间褐飞虱种群对新烟碱类药剂产生不同程度的抗药性,其中对吡虫啉产生高水平到极高水平抗性,对氯噻啉和噻虫嗪分别产生中等水平和低水平的抗药性,对呋虫胺和烯啶虫胺仍然处于敏感性阶段。此外,褐飞虱种群对噻嗪酮(昆虫生长调节剂)产生低水平到中等水平抗性。长期大面积使用化学药剂是褐飞虱产生抗药性的重要原因。因此,必须加强褐飞虱的抗性治理,以延缓其抗药性进一步发展。     

西花蓟马对烯啶虫胺、噻虫胺和噻虫嗪的抗性风险和抗性稳定性

为明确使用新烟碱类杀虫剂烯啶虫胺、噻虫胺和噻虫嗪防治入侵害虫西花蓟马的抗性风险及抗性稳定性,本研究采用芸豆浸药法对西花蓟马敏感种群初羽化雌成虫进行连续筛选获得抗性种群,根据抗性现实遗传力计算公式分析西花蓟马对上述3种杀虫剂的抗性风险,预测其抗性发展速度,并测定抗性稳定性。结果表明: 经过30代抗性筛选,西花蓟马对烯啶虫胺、噻虫胺和噻虫嗪均达到高水平抗性(44.7、45.5和32.7倍)。西花蓟马对噻虫胺、烯啶虫胺和噻虫嗪的抗性发展速度依次降低,抗性现实遗传力分别为0.1503、0.1336和0.1258。对抗性种群在无选择压力下继续饲养10代,西花蓟马对烯啶虫胺、噻虫胺和噻虫嗪的抗性水平均出现一定程度的下降,但均未能恢复到敏感性水平。抗性选育后,西花蓟马若虫与成虫对杀虫剂的敏感性差异显著缩小,西花蓟马敏感种群及抗性种群若虫对上述3种杀虫剂的敏感性显著高于成虫。西花蓟马对烯啶虫胺、噻虫胺和噻虫嗪均存在高抗风险,噻虫嗪的抗性上升速度较慢且抗性稳定性最低。因此,在西花蓟马若虫期使用噻虫嗪有利于西花蓟马防治。     

贵州稻区褐飞虱种群对六种杀虫剂的抗性动态

【目的】为明确贵州褐飞虱Nilaparvata lugens种群对常用杀虫剂的抗性水平。【方法】在室内采用浸渍法测定了2013-2015年采自贵州黄平、桐梓和开阳3地的褐飞虱种群对6种杀虫剂(吡虫啉、噻虫嗪、异丙威、噻虫胺、啶虫脒和醚菊酯)的抗性。【结果】贵州褐飞虱种群对不同的杀虫剂存在着抗性差异。与敏感品系相比,2013-2015年间3地田间褐飞虱种群对吡虫啉、噻虫嗪、异丙威、噻虫胺的抗性均达到中等水平抗性,抗性倍数(resistance ratio,RR)分别为21.88~95.38,10.91~69.36,13.00~57.23和23.11~39.54倍;而对啶虫脒和醚菊酯仍处于敏感阶段,RR分别为0.47~0.75和0.41~0.85倍。【结论】褐飞虱对吡虫啉和噻虫嗪的抗性较高,可能与近年来广泛地大量使用有关。本研究的抗性动态监测结果对贵州稻区褐飞虱的杀虫剂种类调整及施药策略等具有重要指导作用。     

湖北稻区褐飞虱田间种群对常用杀虫剂抗药性监测

【目的】明确目前褐飞虱Nilaparvata lugens田间种群对常用防治药剂的抗性现状,为制定褐飞虱的科学用药策略提供科学依据。【方法】于2009-2014年采用稻茎浸渍法监测了湖北褐飞虱武穴梅川、枣阳十里铺、孝感陈店、鄂州长港和武汉江夏稻田的褐飞虱田间种群对11种杀虫剂的敏感性。【结果】湖北稻区褐飞虱田间种群已对吡虫啉(抗性倍数RR=101.8~1 239.4)、噻嗪酮(RR=15.9~1 326.3)产生高水平抗性;对噻虫嗪(RR=24.9~146.5)产生中等水平至高水平抗性;对噻虫胺(RR=9.9~16.5)、呋虫胺(RR=13.5~15.9)、乙虫腈(RR=18.3~60.4)、毒死蜱(RR=17.4~29.8)、异丙威(RR=13.9~46.0)产生中等水平抗性;对啶虫脒(RR=5.1~9.9)产生低水平抗性;对噻虫啉(RR=3.9~7.1)处于敏感至低水平抗性水平;对醚菊酯(RR=1.3~4.9)处于敏感水平。此外,褐飞虱对噻虫嗪、噻嗪酮抗性上升明显,同时褐飞虱对吡虫啉抗性也有上升的趋势。【结论】仍需暂停吡虫啉、噻嗪酮在水稻上防治稻飞虱,严格限制吡蚜酮在水稻上的使用次数;醚菊酯可作为吡虫啉、噻嗪酮和吡蚜酮的替代药剂或轮换药剂。     

新烟碱类杀虫剂对新菠萝灰粉蚧的毒力

新菠萝灰粉蚧Dysmicoccus neobrevipes Beardsley是近年我国新发现的一种外来物种,是危害剑麻的主要害虫之一,本研究旨在筛选出防治新菠萝灰粉蚧的有效杀虫剂。采用喷雾法测定了啶虫脒、呋虫胺、噻虫胺、噻虫嗪和烯啶虫胺等5种新烟碱类杀虫剂对新菠萝灰粉蚧不同虫态的室内毒力。研究结果表明:5种新烟碱类杀虫剂对新菠萝灰粉蚧均有显著的触杀作用,对新菠萝灰粉蚧的毒力随着龄期的增长而减小。其中,烯啶虫胺对新菠萝灰粉蚧的毒力最高,对新菠萝灰粉蚧1龄、2龄、3龄若虫和雌成虫的LC_(50)分别为0.1406 mg/L、0.1550 mg/L、0.3870 mg/L和0.5060 mg/L。啶虫脒和噻虫嗪的毒力低于烯啶虫胺,呋虫胺和噻虫胺的毒力最低。不同龄期新菠萝灰粉蚧对同一药剂的敏感性表现为:1龄2龄3龄雌成虫。烯啶虫胺对新菠萝灰粉蚧的触杀毒力最好,可作为防治新菠萝灰粉蚧的备选药剂。     

不同药剂对Q型烟粉虱的防治效果评价

研究不同药剂对Q型烟粉虱Bemisia tabaci(Gennadius)的防治效果,为该虫的化学药剂防治提供理论依据。以烟粉虱成虫为试材,采用浸叶法,进行10种药剂对烟粉虱的室内毒力测定实验;采用喷雾法,在大棚黄瓜田进行10种单剂和9种混剂对烟粉虱的防治效果试验。其中阿维菌素对烟粉虱成虫的毒力最高,其LC50为2.8609mg/L,精高效氯氟氰菊酯对烟粉虱成虫的毒力最低,其LC50为389.1049mg/L,乙基多杀菌素对烟粉虱成虫无杀虫效果。9种药剂对烟粉虱成虫的毒力大小顺序为:阿维菌素啶虫脒高效氯氟氰菊酯高效氯氰菊酯氟啶虫胺腈氟啶虫酰胺螺虫乙酯噻虫嗪精高效氯氟氰菊酯。10种药剂在田间对烟粉虱的防效依次为:噻虫嗪阿维菌素氟啶虫胺腈氟啶虫酰胺精高效氯氟氰菊酯啶虫脒螺虫乙酯高效氯氟氰菊酯高效氯氰菊酯乙基多杀菌素。9种混剂的防效试验表明,有6种混剂对烟粉虱的防治效果比单剂防治效果好,其中效果最好的是阿维菌素与三种新烟碱类药剂的混用。     

三种杀虫剂对烟粉虱优势寄生蜂海氏桨角蚜小蜂的安全性评价

为评价噻虫嗪、阿维菌素和氟啶虫胺腈对烟粉虱优势寄生蜂海氏桨角蚜小蜂Eretmocerus hayati的安全性,采用琼脂保湿浸叶法分别测定了3种杀虫剂对烟粉虱成虫和海氏桨角蚜小蜂成蜂的室内毒力以及对海氏桨角蚜小蜂蛹羽化率的影响.结果表明,噻虫嗪、阿维菌素和氟啶虫胺腈对烟粉虱的LC50分别为453.76 mg/L、2.00 mg/L和29.47 mg/L,对海氏桨角蚜小蜂成蜂的LC50分别为0.23 mg/L、1.07 mg/L和0.64 mg/L.通过风险系数评估,表明阿维菌素对海氏桨角蚜小蜂成蜂安全,而噻虫嗪和氟啶虫胺腈对该蜂成蜂具有轻微到中度毒性.3种杀虫剂在烟粉虱和寄生蜂之间的选择性毒力指数表明噻虫嗪对海氏桨角蚜小蜂的负向选择性最强,其次是氟啶虫胺腈,阿维菌素最弱.3种杀虫剂均可显著降低海氏桨角蚜小蜂蛹的羽化率,对蛹的毒性为轻微有害,风险等级为2级.本研究结果将为烟粉虱综合治理中协调使用寄生蜂和化学药剂奠定理论基础.     

六种新烟碱类杀虫剂和三氟苯嘧啶对黄胸蓟马及南方小花蝽的选择毒性

【目的】评估6种新烟碱类杀虫剂和1种新型杀虫剂三氟苯嘧啶对黄胸蓟马Thrips hawaiiensis及其天敌南方小花蝽Orius strigicollis的选择毒性,为杀虫剂与南方小花蝽联合防控黄胸蓟马提供依据。【方法】采用药膜法测定吡虫啉、呋虫胺、氟吡呋喃酮、氯噻啉、烯啶虫胺和噻虫嗪6种新烟碱类杀虫剂及三氟苯嘧啶对黄胸蓟马成虫的毒力及对南方小花蝽5龄若虫的急性毒性,并评估其对南方小花蝽5龄若虫的暴露风险。【结果】供试的7种杀虫剂对黄胸蓟马成虫的半致死用量(median lethal rate, LR₅₀)均低于田间最大推荐用量。氯噻啉对黄胸蓟马成虫的LR₅₀值最低(0.183 g a.i/hm²),显著低于其他杀虫剂;氟吡呋喃酮和三氟苯嘧啶对黄胸蓟马成虫的LR₅₀值分别为3.066和3.949 g a.i/hm²,显著高于其他杀虫剂;两种烯啶虫胺制剂(20%烯啶虫胺可溶液剂和10%烯啶虫胺水剂)对黄胸蓟马成虫的LR₅₀分别为0.327和0.201 g a.i/hm²;两种噻虫嗪制剂(70%噻虫嗪水分散粒剂和25%噻虫嗪水分散粒剂)对黄胸蓟马成虫的LR₅₀值分别为0.970和0.685 g a.i/hm²;不同剂型和含量的烯啶虫胺和噻虫嗪对黄胸蓟马成虫的毒力差异显著。测试的6种新烟碱类杀虫剂对南方小花蝽5龄若虫的LR₅₀值均低于田间最大推荐用量,而三氟苯嘧啶对南方小花蝽5龄若虫的LR₅₀值高于田间最大推荐用量。三氟苯嘧啶对南方小花蝽5龄若虫的毒性最低(LR₅₀>65.736 g a.i/hm²),吡虫啉和呋虫胺次之(LR₅₀值分别为21.317和24.486 g a.i/hm²)。吡虫啉、呋虫胺、三氟苯嘧啶对黄胸蓟马成虫和南方小花蝽5龄若虫具有较高的选择毒性。三氟苯嘧啶和吡虫啉对农田内、农田外南方小花蝽的风险均可接受,氯噻啉和噻虫嗪均不可接受。【结论】黄胸蓟马成虫对6种新烟碱类杀虫剂和三氟苯嘧啶均具极高的敏感性,其中以吡虫啉和三氟苯嘧啶对南方小花蝽5龄若虫的风险较低;三氟苯嘧啶与南方小花蝽兼容性较高,二者在黄胸蓟马的联合防控中具备良好的潜力。     

新烟碱类和大环内酯类杀虫剂对四种赤眼蜂成蜂急性毒性和安全性评价

为了明确新烟碱类和大环内酯类杀虫剂对天敌赤眼蜂Trichogramma spp.的影响, 在室内采用药膜法测定了其对稻螟赤眼蜂Trichogramma japonicum Ashmead、 亚洲玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen、 拟澳洲赤眼蜂Trichogramma confusum Viggiani和广赤眼蜂Trichogramma evanescens Westwood成蜂的急性毒性, 并进行了安全性评价。急性毒性测定结果表明： 在测定的新烟碱类药剂中, 噻虫嗪对拟澳洲赤眼蜂和稻螟赤眼蜂表现出最高的急性毒性, 其LC₅₀分别为0.24 (0.21~0.27) 和0.40 (0.37~0.44) mg a.i./L; 其次为烯啶虫胺, 该药剂对上述两种赤眼蜂的LC₅₀分别为0.83 (0.74~0.96) 和0.72 (0.65~0.80) mg a.i./L; 而吡虫啉对亚洲玉米螟赤眼蜂和拟澳洲赤眼蜂的毒性最低, 其LC₅₀分别为502.13 (459.80~549.62)和752.62 (687.51~828.63) mg a.i./L。在测定的大环内酯类药剂中, 阿维菌素对稻螟赤眼蜂的急性毒性最高, 其LC₅₀为0.49 (0.46~0.65) mg a.i./L, 而甲氨基阿维菌素苯甲酸盐对拟澳洲赤眼蜂表现出最低的急性毒性, 其LC₅₀为21.76 (19.59~24.40) mg a.i./L。安全性评价结果表明, 吡虫啉、 啶虫脒、 氯噻啉和甲氨基阿维菌素苯甲酸盐对4种赤眼蜂为低风险~中等风险性, 安全性系数为0.57~23.54; 噻虫啉和依维菌素对4种赤眼蜂却为中等风险~高风险性, 安全性系数为0.16~3.45; 而烯啶虫胺、 噻虫嗪和阿维菌素对4种赤眼蜂为高风险~极高风险性, 安全性系数为0.01~0.15。本研究测定的大部分杀虫剂对赤眼蜂都有一定的急性毒性风险。因此, 在害虫综合治理中应谨慎使用新烟碱类和大环内酯类杀虫剂尤其是烯啶虫胺、 噻虫嗪和阿维菌素, 以免造成对赤眼蜂的大量杀伤。     

Assessment of toxicity risk of insecticides used in rice ecosystem on Trichogramma japonicum, an egg parasitoid of rice lepidopterans

Both chemical and biological methods are essential for control of insects, for example, lepidopterans, on rice. Thus, it is important to know the effect of chemicals on the biological control agents. In this study, we assessed the toxicity of commonly used insecticides on a biological control agent, Trichogramma japonicum Ahmead (an egg parasitoid of rice lepidopterans) by using a dry film residue method. Results showed that thirty insecticides from seven chemical classes exhibited various degree of toxicity to this parasitoid. Among the seven classes of chemicals tested, organophosphates (chlorpyrifos, fenitrothion, phoxim, profenofos, and triazophos) and carbamates (carbaryl, carbsulfan, isoprocarb, metolcarb, and promecarb) exhibited the highest intrinsic toxicity to T. japponicum, with an LC50 of 0.035 (0.029-0.044) to 0.49 (0.34-0.87) mg active ingredient (a.i.) L(-1), followed by antibiotics (abamectin, emamectin benzoate, and ivermectin), phenylpyrazoles (butane-fipronil, ethiprole, and fipronil), pyrethroids (cyhalthrin, cypermethrin, fenpropathrin, and lambda-cyhaothrin), and neonicotinoids (acetamiprid, imidacloprid, imidaclothiz, nitenpyram, thiacloprid, and thiamethoxam). Moreover, the insect growth regulator insecticides (chlorfluazuron, fufenozide, hexaflumuron and tebufenozide) exhibited the lowest toxicity to the wasps with an LC50 of 3,383 (2406-5499) to 30206 (23107-41008) mg ai. L(-1). Risk quotient analysis showed that phenylpyrazoles, pyrethroids, insect growth regulators, neonicotinoids (with the exception of thiamethoxam), and antibiotics (with the exception of abamectin) are classified as safe agents to the parasitoid, while organophosphates and carbamates are classified as slightly, moderately, or highly toxic agents to the parasitoid. The data presented in this paper provided useful information on the selection of compatible insecticides with T. japonicum.     

苯甲酰基脲类杀虫剂对绿盲蝽的生物活性及亚致死影响

本文系统地比较了有代表性的4种苯甲酰基脲类杀虫剂对绿盲蝽Apolygus lucorum(Meyer-Dür)的生物活性和亚致死剂量对绿盲蝽生长发育及繁殖的影响。结果表明,苯甲酰基脲类杀虫剂对绿盲蝽各龄若虫均有较高的毒力,供试苯甲酰基脲类杀虫剂中,氟啶脲对绿盲蝽2龄若虫的毒力最高,其LC50为51.63 mg/L;氟铃脲对其3龄若虫毒力最高,其LC50为66.87 mg/L;杀铃脲对绿盲蝽4龄若虫毒力最高,其LC50为93.04 mg/L,3种药剂毒力均高于马拉硫磷。以4种苯甲酰基脲类杀虫剂LC30～40剂量处理绿盲蝽若虫后,对其存活若虫的生长发育和繁殖产生明显的后续影响。氟铃脲对试虫的影响最大,处理2龄若虫,表现为其若虫发育历期延长、成虫产卵量略有降低、成虫寿命降低;处理4龄若虫,羽化率降低、成虫产卵量、成虫寿命均降低。     

Effects of Selected Chemical Pesticides on Agamermis unka (Nematoda: Mermithidae), a Parasite of the Brown Plant Hopper,Nilaparvata lugens

Selected commercial and technical grade pesticides were tested against the egg, preparasite and adult stages of Agamermis unka , a nematode parasite of the brown planthopper, Nilaparvata lugens . The commercial insecticide, diazinon (LC = 0.37 ppm), was most toxic to the 50 preparasites, followed by phenthoate (LC = 0.43 ppm), BPMC (LC = 0.44 ppm), IBP 50 50 (LC = 0.46 ppm), cartap hydrochloride (LC = 0.82 ppm) and buprofezin + isoprocarb 50 50 (LC = 1.11 ppm). The least toxic commercial pesticide tested was the fungicide, pencycuron 50 (LC = 2.19 ppm). Out of 12 technical grade insecticides tested, phenthoate, monocrotophos, 50 diazinon and carbofuran (LC = 0.37-0.46 ppm) were highly toxic to the preparasites, followed by 50 buprofezin, BPMC and fenitrothion (LC = 0.74-0.86 ppm). Fenthion, etofenprox, chlorpyrifos, 50 imidacloprid and MIPC (LC = 1.11-2.19 ppm) were the technical grade insecticides least toxic 50 to the preparasites. Most preparasites survived for up to 24 h at the low insecticide concentrations (0.63 and 0.31 ppm). Preparasites that were exposed to BPMC for 24 h at concentrations as high as 5.0 ppm and survived the treatments infected brown planthopper nymphs. Four selected insecticides-chlorpyrifos, BPMC, imidacloprid and carbofuran-had significant adverse effects on A. unka egg hatching. Eggs that were in the insecticide solution for 168 h fared poorly with imidacloprid having the best survival ( > 2% of the eggs hatching at 0.04 ppm). No eggs hatched from the other insecticide treatments. Three selected insecticides, BPMC, imidacloprid and chlorpyrifos, tested against adult A. unka showed that most adults survived the exposure to the insecticides between 0.31 and 2.5 ppm. At 5.0 ppm of BPMC or chlorpyrifos none of the adults survived, whereas with imidacloprid 70% of the adults survived. Egg deposition by the surviving adults was greatly reduced in those treated with the insecticides compared with those in the controls. Imidacloprid had some negative impact on the preparasites' ability to infect BPH nymphs, but it had the least detrimental effect of the insecticides tested on preparasite survival and on the eggs and adults of A. unka .     

三种杀虫剂对褐飞虱海藻糖含量和海藻糖酶活性的影响

为了解农药处理导致褐飞虱Nilaparvata lugens (Stål）飞行能力增强的生理机制, 本文采用蒽酮法和酶促反应终止法, 研究了吡虫啉、 三唑磷和溴氰菊酯3种杀虫剂亚致死剂量对褐飞虱3龄、 5龄若虫及长、 短翅型雌雄成虫体内海藻糖含量和海藻糖酶活性的影响。结果表明： 杀虫剂处理的褐飞虱3龄若虫海藻糖含量和海藻糖酶活性与对照相比没有显著差异（P>0.05）。40 mg/L三唑磷处理的褐飞虱5龄若虫体内海藻糖含量显著低于对照（P<0.05）, 比对照降低了24%; 而20和40 mg/L三唑磷处理的褐飞虱5龄若虫海藻糖酶活性显著高于对照（P<0.05）, 分别比对照高出了100%和129%。10 mg/L吡虫啉, 20 和40 mg/L三唑磷以及3和6 mg/L溴氰菊酯处理的褐飞虱短翅雌成虫和雄成虫体内海藻糖含量显著低于对照（P<0.05）, 雌成虫体内海藻糖含量比对照分别降低了36%, 53%, 67%, 58%和69%, 雄成虫体内海藻糖含量比对照分别降低了59%, 71%, 65%, 70%和77%; 而40 mg/L三唑磷以及3和6 mg/L溴氰菊酯处理的褐飞虱短翅型雌成虫和雄成虫体内海藻糖酶活性显著高于对照（P<0.05）, 雌成虫体内海藻糖酶活性比对照分别高出了124%, 100%和88%, 雄成虫体内海藻糖酶活性比对照分别高出了146%, 132%和118%。10 mg/L吡虫啉, 40 mg/L三唑磷和3 mg/L溴氰菊酯处理的褐飞虱长翅型雌成虫和雄成虫海藻糖含量显著低于对照（P<0.05）, 雌成虫海藻糖含量比对照分别降低了44%, 34%和37%, 雄成虫体内海藻糖含量比对照降低了48%, 54%和43%; 而5和10 mg/L吡虫啉处理的长翅型雌成虫和雄成虫海藻糖酶活性显著高于对照（P<0.05）, 雌成虫体内海藻糖酶活性比对照分别高出了317%和300%, 雄成虫体内海藻糖酶活性比对照分别高出了170%和97%。这些结果说明这3种杀虫剂亚致死剂量处理可以增强褐飞虱体内海藻糖酶活性, 并导致海藻糖含量下降。本研究结果对深入阐明农药诱导褐飞虱再猖獗及杀虫剂处理增强其飞行能力的生理机制具有一定的科学价值。     

Effects of alpha-mangostin from mangosteen pericarp extract and imidacloprid on Nilaparvata lugens (Stal.) and non-target organisms: toxicity and detoxification mechanism

The brown planthopper, Nilaparvato lugens Stat. (BPH) is the most devastating insect pest in rice fields. Outbreaks of BPH, which are resistant to many synthetic insecticides, can cause total rice crop loss. This research was done to evaluate the efficiency of extracts of mangosteen pericarp (Garcina mangostana L.) as an alternative control of BPH Thailand strain. Topical spraying was applied to various stages of nymphal and adult BPH to determine toxicity. An ethanol extract of mangosteen pericarp extract gave the best control of BPH, with LC50 of 4.5% w/v (r2 = 0.95) with 3rd instar BPH nymphs when compared with the other solvents, hexane, acetone and dichloromethane. The active compound, alpha-mangostin showed an LC50 of 5.44%w/v (r2 = 0.88). The toxicity of this extract was less than that of Imidacloprid which showed an LC50 of 0.0042% w/v (r2 = 0.99). The toxicity to non-target organisms was determined. This extract showed toxicity to guppies ((LC50 = 2.53 and 4.27 ppm for females and males, respectively; r2 = 0.97 and 0.97, respectively), bees (LC50 = 4.38% w/v, r2 = 0.95) and mice (no oral acute toxicity and no dermal inflammation but showed eye irritation in 1 day which became normal within 3 days). In vitro detoxification enzyme activities of carboxylesterase, acetylcholinesterase and glutathione-s-transferase from BPH after 24 hours exposure were also observed. Carboxylesterase showed stronger activity than other enzymes. Toxicity in terms of LC50 values of both the extract and imidacloprid treatments increased in each generation. The LC50 values for each generation were 4.22-6.67 after sequential spraying. After the ethanol extract was kept at 4 degrees C, room temperature and 55 degrees C for 3 months, the quantity of alpha-mangostin and the BPH control efficiency was lower at 55 degrees C than those for other temperatures. The results from this research indicate that mangosteen pericarp extract can be an alternative insecticide for the control of BPH, which may possess high efficiency, cause with fewer environmental problems and result in less resistance in the BPH.     

山东省不同地区灰飞虱对溴氰虫酰胺的敏感性及亚致死剂量溴氰虫酰胺对灰飞虱解毒酶活性的影响

为了探究山东不同地区灰飞虱种群对溴氰虫酰胺的敏感性水平差异,在室内采用稻苗浸渍法和点滴法分别测定了溴氰虫酰胺对泰安、莱芜、鱼台(分别采自小麦和水稻)、济南和济阳6个灰飞虱种群3龄若虫和成虫的毒力,同时测定了亚致死剂量(LD 10和LD 30)溴氰虫酰胺对灰飞虱成虫体内的酯酶(ESTs)、谷胱甘肽-S-转移酶(GSTs)和多功能氧化酶(MFO)活性的影响。稻苗浸渍法结果表明,溴氰虫酰胺对6个灰飞虱种群3龄若虫的LC 50值介于8.5193~11.0524 mg/L,对成虫的LC 50值介于10.4245~12.4904 mg/L。点滴法测定结果表明,溴氰虫酰胺对6个灰飞虱种群3龄若虫的LD 50值在0.9239×10-3~1.1318×10-3μg/头之间,对成虫的LD 50值在1.0933×10-3~1.2619×10-3μg/头之间。在溴氰虫酰胺亚致死剂量(LD 10和LD 30)处理下,灰飞虱体内3种解毒酶活性均被诱导上升,其中GSTs酶活力上升最显著。结果表明,山东不同地区田间灰飞虱种群对溴氰虫酰胺的敏感性差异不大,同一地区灰飞虱种群不同虫态对溴氰虫酰胺的敏感性也无明显差异。GSTs可能会在灰飞虱对溴氰虫酰胺后续抗性形成中起作用。