转Bt基因棉种植前后3个棉铃虫种群对4种杀虫剂的抗性变化

分别于1990年、1992年、2001年和2005年从山东泰安、山东夏津和湖北天门采集3个棉铃虫H elicoverpa arm igera种群,采用点滴法测定了4种杀虫剂对其的毒力,以监测各种群的抗药性变化趋势。结果表明:19901992年3个种群棉铃虫对氰戊菊酯的抗性增长迅速(13.256.1倍);19922001年抗性增长速度有所减缓(3.111.0倍);20012005年抗性水平降低。3个种群棉铃虫对灭多威和辛硫磷的抗性变化趋势与氰戊菊酯的基本相似,但抗性水平较低;对硫丹则均一直处于敏感水平。引起抗药性变化的原因主要与各类药剂的使用频率和转B t基因抗虫棉的大面积推广有关。     

杀虫剂对中华草蛉幼虫的毒力及其选择性研究

用点滴法测定了 13种杀虫剂对中华草蛉 (Chrysopa sinia (Jieder) )幼虫的毒力 ,按敏感性由高至低依次为 :久效磷、氯氟氰菊酯、灭多威、丙溴磷、辛硫磷 >氧乐果、甲基对硫磷、甲基毒死蜱 >硫丙磷 >抑太保 >氰戊菊酯 >阿维菌素及硫丹。同时测定了多种药剂对棉铃虫 (H elicoverp a armigera Hübner)、棉蚜 (Aphis gossyp ii Glover)的毒力 ,证明多数有机磷杀虫剂及灭多威为非选择性药剂 ;具有选择性的药剂中 ,硫丹选择性最高 ,其次为氰戊菊酯。氯氟氰菊酯对中华草蛉与棉铃虫表现出一定程度的选择性 ,但对中华草蛉与棉蚜则表现为非选择性 ;随棉蚜抗药性提高 ,各药剂选择性降低。     

棉铃虫对溴氰菊酯、三氟氯氰菊酯及其复配剂的抗性趋势与交互抗性

在70％的高选择压下,分别用溴氰菊酯、三氟氯氰菊酯和凯明2号(50％辛硫磷·甲基对硫磷·三氟氯氰乳油,即含三氟氯氰菊酯的复配药剂)对室内饲养了12代未经农药处理的棉铃虫Helicoverpa armigera(H(?)bner)敏感品系进行了抗性筛选。结果,经连续筛选至第12代的LD_(50)值与筛选前第1代的LD_(50)值比较,抗溴氰菊酯种群对溴氰菊酯的抗性为136.7倍,属高抗水平;抗三氟氯氰菊酯种群对三氟氯氰菊酯的抗性为9.5倍,抗凯明2号种群对凯明2号的抗性为3.4倍,均属低抗水平。用8种常用杀虫剂分别对这3个种群在停止上述杀虫剂筛选2代后进行了交互抗性分析。结果表明,3个种群平均对8种杀虫剂的抗性倍数中,对溴氰菊酯、氰戊菊酯、灭多威的抗性极显著高于其余5种杀虫剂;3个种群的平均抗性倍数之间差异极显著,顺序依次为抗溴氰菊酯种群>抗三氟氯氰菊酯种群>抗凯明2号种群;以平均抗性倍数表示的抗性种群与杀虫剂的交互作用有以下几个结果:①高抗溴氰菊酯的种群对氰戊菊酯和灭多威有极显著的交互抗性,但对三氟氯氰菊酯和凯明2号仍反应敏感。②抗三氟氯氰菊酯和抗凯明2号的2个种群对溴氰菊酯有极显著的交互抗性;抗三氟氯氰菊酯种群对灭多威和氰戊菊酯有一定抗性,抗凯明2号种群对硫丹有一定抗性。     

十三种杀虫剂对七星瓢虫的毒力研究

本文分别采用微量点滴法和玻璃药膜法测定了6种杀虫单剂及7种杀虫混剂对七星瓢虫4龄幼虫及其成虫的室内毒力。结果表明：6种单剂对七星瓢虫成、幼虫的毒力顺序完全一致，即高效氯氟氰菊酯＞辛硫磷＞灭多威＞甲基对硫磷＞甲胺磷＞硫丹；7种混剂对以上2种虫态的毒力顺序有所差别，但其中均以甲胺磷 硫丹表现最为安全；联合毒力以甲基对硫磷 辛硫磷、高效氯氟氰菊酯 辛硫磷一致表现为拮抗，灭多威 硫丹、甲胺磷 硫丹一致表现为增毒，高效氯氟氰菊酯 灭多威一致表现为相加作用，而灭多威 甲基对硫磷、高效氯氟氰菊酯 硫丹对2种虫态的联合毒力表现不一。     

十一种杀虫剂的亚致死剂量对中华草蛉幼虫结茧和羽化的影响

11种杀虫剂在引起中华草蛉(Chrysopa sinia (Jieder))幼虫死亡率30%左右的选择压下,对其结茧和羽化都有不同程度的影响.硫丹在明显高于田间常用浓度的143倍时,引起草蛉幼虫死亡率23.3%,对该虫结茧率和羽化率影响不大,分别为86.0%和83.0%;氰戊菊酯、甲丙硫磷、氧乐果、甲基对硫磷、辛硫磷、丙溴磷对幼虫结茧和羽化的影响相对较低,草蛉校正结茧率和羽化率为77.5%～93.7%和61.0%～74.8%;甲基毒死稗、氯氟氰菊酯、灭多威对草蛉幼虫生命力的影响很大,尤其使成虫羽化率明显降低,且以灭多威的影响最甚,50mg/kg处理后幼虫结茧率仅34.9%,成虫羽化率为12.4%;抑太保虽然对草蛉幼虫的杀伤力小,对草蛉幼虫的结茧影响不大,但对成虫羽化影响很大,处理浓度为500 mg/kg时,幼虫结茧率为84.8%,成虫羽化率仅13.5%.     

4种棉蚜抗药性种群的生命力及繁殖力

用4种杀虫剂以浸渍法分别累代处理敏感棉蚜,以选育抗药性。每选育4代进行1次毒力测定及生命力和繁殖力的观察。选育至12代,棉蚜对溴氰菊酯的抗性倍数达4031.4倍,对久效磷、灭多威及硫丹的抗性倍数分别仅为6.3、6.1及4.0倍。棉蚜对溴氰菊酯抗性水平较低时,其生命力及繁殖力略低于敏感品系,随着抗性水平的提高,其生命力和繁殖力也随之增强,RF_(8)接近敏感品系的水平,RF_(12)及RF_(16)则明显超过。灭多威及硫丹抗性种群随抗性水平的提高,其生命力及繁殖力表现不同程度的降低。久效磷抗性种群,各抗性水平下其生命力和繁殖力与敏感品系相比无显著差异。     

不同种群螟黄赤眼蜂和松毛虫赤眼蜂的抗药性测定

分别测定了螟黄赤眼蜂和松毛虫赤眼蜂各5个不同地理种群对灭多威、溴氰菊酯、辛硫磷的室内抗性水平。结果表明,不同地区或不同生态条件下的赤眼蜂种群具有抗药性差异。螟黄赤眼蜂的敏感种群为采自吉林省长春市的农场种群,与之比较,其他4个种群对灭多威的LC50的变化范围为其1.93～6.72倍,对溴氰菊酯的LC50为其5.35～39.08倍,对辛硫磷的LC50为其3.49～29.76倍;松毛虫赤眼蜂的敏感种群为采自黑龙江省尚志市的亚布力南种群,与之比较,其他各个种群对灭多威的LC50的变化范围为其9.52～70.66倍,对溴氰菊酯的LC50为其73.12～288.16倍,对辛硫磷的LC50的变化范围为11.84～50.38倍。     

我国西南烟区桃蚜Myzus persicae (Sulzer)的抗药性水平

采用毛细管点滴法测定了我国西南烟区云南和贵州省的10个桃蚜Myzus persicae（Sulzer）种群对氰戊菊酯、氧化乐果、灭多威和吡虫啉的抗性。结果表明，云南楚雄种群对氰戊菊酯的抗性高达26．87倍，对氧化乐果、灭多威、吡虫啉的抗性分别为敏感种群的10．02、6．00和5．83倍。云南大理、丽江、石林和曲靖4个种群对氰戊菊酯的抗性分别达24．98、14．94、11．11和10．33倍，抗性水平也较高，但对氧乐果、灭多威和吡虫啉仍较为敏感，应尽早实施抗性治理措施。贵州省的5个种群仍然处在敏感阶段。     

十一种杀虫剂的亚致死剂量对中华草蛉幼虫结茧的羽化和影响

11种杀虫剂在引起中华草蛉（Chrysopa sinia (Jieder)幼虫死亡率30％左右的选择压下，对其结茧和羽化都有不同程度的影响。硫丹在明显高于田间常用浓度的143倍时，引起草蛉幼虫死亡率23.3％，对该虫结茧率和羽化率影响不大，分别为86.0％和83.0％；氰戊菊酯、甲丙硫磷、氧乐果、甲基对硫磷、辛硫磷、丙溴磷对幼虫结茧和羽化的影响相对较低，草蛉校正结茧率和羽化率为77.5％-93.7％和61.0％-74.8％；甲基毒死稗、氯氟氰菊酯、灭多威对草蛉幼虫生命力的影响很大，尤其使成虫羽化率明显降低，且以灭多威的影响最甚，50mg/kg处理后幼虫结茧率仅34.9％，成虫羽化率为12.4％；抑太保虽然对草蛉幼虫的杀伤力小，对草蛉幼虫的结茧影响不大，但对成虫羽化影响很大，处理浓度为500mg/kg时，幼虫结茧率为84.8％，成虫羽化率仅13.5％。     

不同寄主植物棉蚜酯酶对杀虫剂不敏感性的频率分布

通过生物测定和生化分析研究了花椒棉蚜(HA)和棉花棉蚜(MA)种群对杀虫剂的抗性及其α-乙酸萘酯(α-NA)酯酶和乙酰胆碱酯酶(AChE)对杀虫剂的不敏感性。结果表明,MA种群对甲基对硫磷、辛硫磷和灭多威的耐药性均高于HA种群;MA种群中具有高α-NA酯酶活力的个体比HA种群多,甲基对硫磷对HA和MA种群α-NA酯酶的抑制率达30％时的个体累计频率分别为37％和65％;抑制率大于50％时的累计频率分别为18％和1％;灭多威对HA种群棉蚜AChE的抑制作用高于MA种群。说明MA种群对有机磷的抗性可能与α-NA酯酶活力的增高和对杀虫剂的不敏感性有关,对灭多威的抗性与AChE敏感度的降低有关。滤纸酯酶反应法和微量滴度酶标板法均能快速、有效地测定棉蚜个体酯酶的频率分布,准确地反映两种群棉蚜酯酶活力的差异。     

新疆棉铃虫自然敏感种群对常用杀虫剂浸叶法的毒力基线

选用阿拉尔棉铃虫自然敏感种群(AL-S),在详细观察2龄中期幼虫的形态、行为特征及比较其生理学特性对药剂敏感性影响的基础上,用生理特性一致的2龄中期幼虫,测定了10种常用杀虫剂浸叶法的毒力基线。结果表明:①2龄中期幼虫的形态和行为特征为头宽≤体宽,体色不透明肉色,体节明显且行动较敏捷。此时2龄幼虫的时龄约为10～22h,体重1.33±0.27mg;②试虫生理特性差异影响对药剂的敏感性。2龄幼虫不同发育历期的敏感性,以前期最敏感,中、后期较接近;雌蛾不同蛾龄的卵发育的2龄幼虫敏感性,以4日龄蛾卵的幼虫敏感性最低,7日龄蛾卵最敏感,5、6日龄蛾的敏感性相近,且介于上述二者之间。故在测定毒力基线时,为保持试虫生理同质性,宜选用5、6日龄雌蛾卵的2龄中期幼虫为佳。③用2龄中期幼虫,获得10种药剂浸叶法的毒力基线,杀虫剂致死中浓度(LC_(50))按以下次序增大:功夫菊酯、溴氰菊酯、氰戊菊酯、硫丹、甲基E605、辛硫磷、毒死蜱、丙溴磷、久效磷、灭多威。     

Studies of insecticide assays and spray deposit recovery in relation to the false codling moth,Cryptophlebia leucotreta Meyrick (Lepidoptera: Tortricidae; subfamily olethreutinae)

Insecticide assays using larvae of Cryptophlebia leucotreta Meyrick (Lepidoptera: Tortricidae; subfamily Olethreutinae) showed that parathion-methyl and monocrotophos were more toxic than fenitrothion and endosulfan. The LD90 were 3.44 mg/kg and 11.0 mg/kg for parathion-methyl and monocrotophos, respectively. The order of relative efficiency of the insecticides was as follows: parathion-methyl, monocrotophos, fenitrothion and lastly endosulfan. When different spray machines were tested for spray deposition on well grown cotton plants, the motorised airblast sprayer effected a more satisfactory deposit recovery on the lower parts of the cotton plants where early and heavy infestation of C. leucotreta to the mature cotton bolls occurs.     

Cross-resistance ofAphis gossypii to selected insecticides on cotton and cucumber

Cross-resistance of a fenvalerate-resistant (R-fenvalerate) strain and an imidacloprid-resistant (R-imidacloprid) strain of the cotton aphidAphis gossypii Glover to methomyl, endosulfan and omethoate was determined on cotton and cucumber in the laboratory. The R-fenvalerate strain had been selected for 16 consecutive generations on cotton, and the R-imidacloprid strain for 12. Compared with the susceptible (S) strains, the resistance in the 17th generation of the R-fenvalerate strain to fenvalerate was 29,035-fold on cotton and 700-fold on cucumber, whereas the resistance in the 13th generation of the R-imidacioprid strain to imidacloprid was 4.7-fold on cotton and 3.6-fold on cucumber. The R-fenvalerate strain did not show any cross-resistance to imidacloprid, methomyl or omethoate on cotton and cucumber, but became slightly cross-resistant to endosulfan (RR [resistance ratio] = 5.8 and 7.4 on cotton and cucumber, respectively). On cotton the R-imidacloprid strain became highly cross-resistant to fenvalerate (RR = 108.9) and slightly cross-resistant to methomyl, endosulfan and omethoate (RR = 6.3, 3.0 and 8.5, respectively). In contrast, on cucumber the R-imidacloprid strain became highly cross-resistant to fenvalerate (RR = 33.5) and slightly cross-resistant to methomyl and omethoate (RR = 7.0 and 3.3, respectively), but did not show any cross-resistance to endosulfan. It appears thatA. gossypii of both resistant strains was more resistant to the tested insecticides on cotton than on cucumber, except for imidacloprid —where the resistance on cotton was not significantly different from that on cucumber.     

不同药剂对甜菜夜蛾幼虫毒力和田间应用效果研究

利用浸渍法分别测定虫螨腈等不同药剂对甜菜夜蛾3龄及5龄幼虫的毒力，结果表明：不同药剂对甜菜夜蛾幼虫的毒力存在明显差异，一些特异杀虫剂对甜菜夜蛾幼虫的毒力普遍高于试验用常规化学杀虫剂的毒力；同一药剂对不同龄期幼虫毒力的差异程度也不同，如虫螨腈、氟啶脲、氟铃脲、甲胺基阿维菌素、阿维菌素、虫酰肼等药剂对甜菜夜蛾3龄及5龄幼虫毒力的差异程度明显低于顺式氯氰菊酯、丙溴磷、灭多威等化学药剂。同时，作者还对12种药剂分别稀释1000倍对甜菜夜蛾5龄幼虫不同时间的毒力进行了观察，除常规化学农药出现中毒现象较快外，虫螨腈、甲胺基阿维菌素也表现较快中毒症状，田间药效试验进一步验证防治甜菜夜蛾宜选用虫螨腈、氟啶脲、氟铃脲、甲胺基阿维菌素、阿维菌素、虫酰肼等药剂。     

新疆喀什棉铃虫敏感性基因保护研究

从新疆喀什采集棉铃虫（Helicoverpa armigera Huebner)在室内建立实验种群,以点滴法测定了该种群对31种杀虫剂的敏感性毒力数据,对所测得的毒力基线进行了排队分析。结果表明,新疆喀什棉区棉铃虫对拟除虫菊酯类杀虫剂、部分有机磷酸酯类杀虫剂如久效磷、丙溴磷、辛硫磷、甲胺磷、蔬果磷和甲基对硫磷等表现敏感;对氨基甲酸酯类的灭多威敏感度接近敏感毒力基线。而对有机磷酸酯类的另一些品种如亚胺硫磷、氧乐果、倍硫磷、敌百虫及其他品种如硫双灭多威、异丙威和硫丹等却表现高度耐性。最后,就新疆棉区棉铃虫对杀虫剂敏感性基因保护进行了讨论。     

美洲斑潜蝇幼虫对杀虫剂的敏感性研究

利用浸叶法测定了美洲斑潜蝇幼虫对１１种不同类型杀虫剂的敏感性。实验结果表明,齐墩螨素对美洲斑潜蝇具有较高的毒力,其ＬＣ_５０仅为０.０８１８ｍｇ／Ｌ,其次是菊酯类杀虫剂溴氰菊酯和高效氯氰菊酯。美洲斑潜蝇对有机磷杀虫剂马拉硫磷、敌敌畏、乙酰甲胺磷、氨基甲酸酯类杀虫剂灭多威和丁硫克百威具有较强的耐药性。     

Comparative activity of Choristoneura fumiferana nucleopolyhedrovirus propagated in different hosts

The biological activity of the Ireland strain of Choristoneura fumiferana (Clem) nucleopolyhedrovirus (CfMNPV) propagated in different hosts was determined to provide the basis upon which genetically modified CfMNPV, or other naturally occurring isolates, should be compared. Occlusion bodies (OB) derived from CF-203 cells were significantly larger and more pathogenic than those propagated in vivo when tested against the fifth larval instar of C fumiferana (Clem) and C occidentalis Freeman. The dose-responses (LD50 and LD95, expressed as occlusion bodies per larva) of C fumiferana larvae to in vitro-propagated OBs were 274 and 5785, respectively. The values of LD50 and LD95 to C occidentalis larvae were 19 and 118, respectively. There were no significant differences in pathogenicity or size when OBs propagated in C fumiferana larvae were tested against either insect species, nor were there significant differences for OBs propagated in C occidentalis larvae. The LD50 and LD95 of in vivo-produced OBs to C fumiferana were 925 and 61988, respectively. The LD50 and LD95 to C occidentalis were 50 and 453, respectively. OBs propagated in vitro had a mean volume of 13.13 microm3, whereas those propagated in vivo ranged from 0.84 to 1.41 microm3. The median survival time-responses (ST50) of fifth-instar C fumiferana or C occidentalis larvae to OBs propagated in vivo were not significantly different from those propagated in vitro at the dosage levels tested. Values of ST50 of C fumiferana larvae to in vitro- and in vivo-produced OBs at dosages causing less than 50% mortality rangedfrom 9.6 to 9.8 days post-inoculation (dpi), whereas a LD95 dose resulted in ST50 values ranging from 7.3 to 7.7 days. ST50 values of C occidentalis larvae at dosages causing less than 50% mortality ranged from 9.8 to 10.2 dpi, whereas a LD95 dose resulted in ST50 values ranging from 9.5 to 9.8 dpi. The median feeding cessation time-response (FT50) of fifth-instar C fumiferana larvae to OBs propagated in vitro (5.7 days) was not significantly different from the FT50 of those propagated in vivo in either insect species (5.3 and 5.7 days) at the dosage level tested (LD95). No significant differences in FT50 values were observed between OBs propagated in either larval host. The FT50 of C occidentalis larvae to OBs propagated in vitro (7.7 days) was not significantly different from that to those propagated in vivo in C occidentalis larvae (7.6days), but somewhat different (7.2 days) from that to those propagated in C fumiferana larvae. Results indicate that CfMNPV can be propagated in vivo in either C fumiferana or C occidentalis larvae (or sequentially through both) without alteration in infectivity, although the use of the CF-203 cell line yields the most biologically active OBs.