氯虫苯甲酰胺亚致死剂量对甜菜夜蛾主要解毒酶活性与生长繁殖的影响

【目的】甜菜夜蛾(Spodoptera exigua)是一种杂食性害虫,在不同环境、药物等选择压力下表现出不同的生长发育特点。氯虫苯甲酰胺是一种新型广谱的鱼尼丁受体杀虫剂,对鳞翅目害虫杀虫活性强。本研究旨在探究氯虫苯甲酰胺亚致死剂量对甜菜夜蛾幼虫3种主要解毒酶——羧酸酯酶(Car E)、谷胱甘肽S-转移酶(GSTs)和多功能氧化酶(MFOs)活性以及对种群繁殖的影响。【方法】采用饲料混毒法测定氯虫苯甲酰胺对SE-Lab品系、SE-Sel品系的毒力,SE-Sel品系由SE-Lab品系经亚致死剂量LC25连续汰选6代得到;通过浸叶法测定磷酸三苯酯(TPP)、顺丁烯二酸二乙酯(DEM)、胡椒基丁醚(PBO)3种酶抑制剂与氯虫苯甲酰胺协同对SE-Lab和SE-Sel品系的毒力增效作用,提前12 h让试虫取食浸渍过酶抑制剂的叶片,对照组取食用0.1%Triton X-100浸渍后的叶片,再分别测定氯虫苯甲酰胺对使用酶抑制剂与未使用酶抑制剂试虫的毒力;在冰上解剖试虫的中肠和脂肪体,并通过离体酶活性测定,分析氯虫苯甲酰胺亚致死剂量与酶抑制剂对甜菜夜蛾体内的3种代谢解毒酶活力的影响;通过记录试虫各个年龄阶段的生长、死亡、产卵量等数据,参照两性生命表理论分析SE-Lab和SE-Sel品系的两性生命表参数差异。【结果】在3种酶抑制剂中PBO增效作用最强,其对甜菜夜蛾SE-Sel品系和SE-Lab品系对氯虫苯甲酰胺的毒力增效比分别为1.58和1.69。在氯虫苯甲酰胺亚致死剂量连续汰选下,甜菜夜蛾体内3种解毒酶活性均被诱导上升,其中MFOs酶活力上升最显著,SE-Sel品系中肠和脂肪体的MFOs活性相对于SE-Lab品系分别提高了2.07和2.10倍,而经氯虫苯甲酰胺亚致死剂量再次诱导的SE-Sel试虫的MFOs活性亦较SE-Lab品系上升4.02和3.44倍;在使用了酶抑制剂后3种解毒酶酶活力均有下降,其中MFOs活性下降最多,其酶比活力仅为未使用酶抑制剂处理的42.3%—44.8%。与SE-Lab品系相比,SE-Sel品系成虫的产卵前期和总产卵前期变长,而产卵量减少;SE-Sel品系的内禀增长率(r)、周限增长率(λ)和净增殖率(R0)均显著小于SE-Lab品系,SE-Lab品系与SE-Sel品系的r分别为0.18和0.16 d~(-1),λ为1.20和1.17 d~(-1),R0为358.42和203.12 d~(-1)。尽管SE-Sel品系的平均世代周期(T)更长,但是与SE-Lab品系无显著差异。【结论】MFOs可能为甜菜夜蛾对氯虫苯甲酰胺解毒代谢过程中的主要解毒酶,在其后续抗性形成中起主要作用;甜菜夜蛾在氯虫苯甲酰胺亚致死剂量作用下,世代周期延长,繁殖力降低,种群增长减缓,氯虫苯甲酰胺亚致死剂量对甜菜夜蛾有持续控制作用。     

Characterisation of spinosad resistance in the housefly Musca domestica (Diptera: Muscidae)

BACKGROUND: Spinosad, a relatively new, effective and safe pesticide, has been widely used in pest control over the last 10 years. However, different levels of resistance to this insecticide have developed in some insects worldwide. RESULTS: After continuous selection for 27 generations, a strain (SpRR) of the housefly developed 247‐fold resistance to spinosad compared with the laboratory susceptible strain (CSS). The estimated realised heritability (h²) of spinosad resistance was 0.14. There was no significant difference in the LD₅₀ values and slopes between reciprocal progenies F₁ and F₁′, and values of 0.33 (F₁) and 0.30 (F₁′) were obtained for the degree of dominance. Chi‐square analysis from responses of self‐bred (F₂) and backcrosses (BC₁ and BC₂) were highly significant, suggesting that the resistance was probably controlled by more than one gene. Synergists piperonyl butoxide (PBO), diethyl maleate (DEM) and S,S,S‐tributyl phosphorotrithioate (DEF) affected the toxicity of spinosad at a low level, and demonstrated that metabolic‐mediated detoxification was not an important factor in conferring resistance to spinosad in the SpRR strain. CONCLUSION: It was concluded that spinosad resistance in the housefly was autosomal and incompletely dominant, and the resistance was probably controlled by more than one gene. These results provide the basic information for designing successful management programmes for the control of houseflies. Copyright © 2011 Society of Chemical Industry     

截形叶螨抗药性主导机制的研究

研究室内汰选培育的截形叶螨(Tetranychus truncatus Ehara)抗性种群表明,截形叶螨抗久效磷的主导机制可能是乙酰胆碱酯酶(AchE)敏感性降低,谷胱甘肽—S—转移酶(GST)和多功能氧化酶(MFO)活性升高。抗三氟氯氰菊酯截形叶螨的主导机制是MFO和羧酸酯酶活性增强,以及羧酸酯酶发生变构,对底物(α—NA)的亲和力(R/S=5)和比活力(R/S=2)上升。生物测定结果TPP、SV_1和PBo对三氟氯氰菊酯都有增效作用,增效比值分别为2、3和6倍。截形叶螨抗三氯杀螨醇的主导机制是GST代谢毒物的能力增强,GST比活力上升(R/S=2),CH_3I对三氯杀螨醇有一定增效作用(2倍)。     

磷酸二铵添加增效剂对小麦-花生轮作系统作物产量和磷肥吸收利用的影响

为明确增值磷肥（磷酸二铵添加增效剂）在小麦-花生轮作体系中的施用效果,采用2年盆栽试验,研究了磷酸二铵（DAP）添加不同增效剂（腐殖酸HA、氨基酸aa和海藻寡糖AOS）对作物产量和磷肥吸收利用的影响。结果表明,与DAP单施处理相比,DAP添加增效剂处理的小麦平均产量显著增加(8.22%～ 16.57%),DAP+aa和DAP+AOS处理的小麦磷累积量显著增加(14.12%和10.59%),但DAP+AOS处理的花生平均产量和磷累积量均显著下降(14.82%和10.59%)。DAP添加增效剂处理的小麦平均磷素农学效率显著增加（24.26%～48.88%）,磷素累积利用率也有不同程度增加,但DAP+AOS处理的花生磷素平均农学效率和累积利用率均显著下降（42.45%和4.91%）。2年小麦-花生轮作后,不施磷土壤中的磷素累积亏缺和有效磷含量分别为0.99 g·pot^-1和1.59 mg·kg^-1;DAP处理分别为3.05 g·pot^-1和3.06 mg·kg^-1,DAP+aa和DAP+AOS处理土壤的有效磷含量较DAP处理下降14.34%和11.82%,但土壤磷盈余量无显著变化。施磷后平均每1 g·pot^-1的磷盈余可使土壤有效磷含量提高0.328 7 mg·kg^-1。本试验条件下,两种作物对DAP添加增效剂后的响应存在明显差异,和DAP单施处理相比,DAP添加增效剂处理均可提高小麦的产量和磷肥利用效率,但DAP+AOS处理的花生产量、磷累积量、磷素平均农学效率和累积利用效率均显著下降。     

3种增效剂与3种烟碱类杀虫剂混配对棉蚜的增效作用

【目的】 分析棉蚜对传统烟碱类杀虫剂吡虫啉、啶虫脒、噻虫嗪的敏感性,研究青皮桔柚、有机硅、激健3种增效剂对棉蚜的增效作用。【方法】 采用浸叶法测,定3种增效剂与3种烟碱类杀虫剂混配后对棉蚜的生物活性及增效作用。【结果】 吡虫啉、啶虫脒、噻虫嗪对棉蚜24 h LC₅₀分别为11.878、24.452、12.110 μg/mL,吡虫啉和噻虫嗪相对毒力分别是啶虫脒的2.059和2.019倍。添加3种增效剂后,9种农药+增效剂组合对棉蚜的毒力均有显著提高,其中吡虫啉+青皮桔油、啶虫脒+有机硅、噻虫嗪+青皮桔油的组合增效作用最佳,对棉蚜24 h LC₅₀分别为0.328、1.987、0.704 μg/mL,增效比分别为36.213、12.306、17.202。【结论】 青皮桔柚、有机硅、激健3种增效剂在新疆棉区棉蚜绿色防控和农药减施增效技术可应用。     

尿素与复合氮肥增效剂配施对水稻氮素利用的影响

采用^15N-尿素进行盆栽和田间试验，研究了复合氮肥增效剂用量、尿素与复合氮肥增效剂配施对水稻生长、籽粒产量和氮素吸收利用的影响。结果表明，适宜用量（施氮量的20％）的复合氮肥增效剂能显著促进水稻幼苗生长发育；尿素全量配施复合氮肥增效剂不影响水稻生长，能显著提高水稻植株Ndff％、氮吸收总量，氮素利用率和^15N的吸收量,尿素减量5％～15％（即减少施氮7．8～23．7kg／hm^2）配施复合氮肥增效剂基本上不影响水稻生长、籽粒产量和吸氮总量，能显著提高氮素的农学效率、生理效率和氮素利用率；植株吸氮总量、净吸收氮量和^15N总吸收量与不施增效剂的处理相当或有所提高。尿素减量达30％以上配施复合氮肥增效剂，对水稻植株生长和氮素吸收利用产生明显不利影响。尿素与施氮量20％的复合氮肥增效剂配施，不影响大田水稻植株生长和单季产量，能提高氮素利用率，节省氮肥投入达15％。     

Esterase inhibition by synergists in the western flower thrips Frankliniella occidentalis

BACKGROUND: Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is among the most important crop pests in the south‐eastern region of Spain. Its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. Use of synergists to inhibit the enzymes involved in insecticide detoxification is widely used to determine their responsibility for insecticide resistance. However, they do not always act as intended or expected, and caution must be exercised when interpreting synergist results. RESULTS: Laboratory‐selected strains of WFT were used to analyse the effects of the synergists piperonyl butoxide (PBO), S,S,S‐tributyl phosphorotrithioate (DEF) and methiocarb on total esterase activity. Significant differences were found, indicating esterase activity inhibition by DEF, a lower effect for methiocarb and a small inhibition of the activity by PBO. Esterase isoenzyme inhibition by these compounds showed a similar result; this assay revealed an extreme sensitivity of Triplet A (resistance‐associated esterases) to DEF. In an in vivo assay carried out with these compounds at different incubation times, only DEF caused posterior in vitro esterase activity inhibition, with a maximum effect 1 h after treatment. CONCLUSION: In this work, only DEF shows true synergistic inhibition of WFT esterases. Copyright © 2011 Society of Chemical Industry     

对莠去津增效的新型油乳剂的配制及选择范围

本文通过大量试验配制出１２种具有商品价值的新型油乳剂，室内和田间验证了其对除草剂莠去津具有明显增效作用。并系统测定了３８种馏分油乳剂对莠去津增效的差异，首次提出了矿物油作除草剂增效剂的选择范围为：碳链长度在１７～３１碳、沸点范围为２７３～４３５℃、粘度在１５～６８ｍｍ２／ｓ（４０℃）间的精炼矿物油。     

不同类型药剂对水稻褐飞虱的活性及复配增效作用

采用稻茎浸渍法测定了18种杀虫剂对褐飞虱的毒力,选活性较好的药剂进行复配,筛选出具有较高活性的混剂,测定不同类型增效剂的增效作用与复合增效作用,并研究混剂与复合增效剂的最佳增效配伍。结果表明,18种药剂对褐飞虱的毒力大小次序为:氟虫腈噻嗪酮烯啶虫胺氟铃脲噻虫嗪甲维盐吡蚜酮阿维菌素丁醚脲毒死蜱速灭威啶虫脒异丙威联苯菊酯吡虫啉高效氯氟氰菊酯三唑磷马拉硫磷,其中氟虫腈的活性最高,是吡虫啉的128.38倍。不同药剂复配中,烯啶虫胺与噻嗪酮(30∶70)复配的共毒系数最高,为246.02。6种增效剂与药剂混配增效作用,以氮酮、有机硅最好,增效比在2.69~2.85之间,并且将两者按40∶60配比后,其联合增效作用有显著提高。     

杀虫剂混用或加增效剂对瓜-棉蚜增效作用及机制的研究

1987年,根据瓜-棉蚜(Aphis gossypii Glov.)对拟除虫菊酯和有机磷杀虫剂的抗性机制,研究了一些有机磷化合物或增效剂,对这两类杀虫剂的增效作用及增效机制。在试验的化合物中,马拉氧磷和虫螨磷对氰戊菊酯有明显的增效作用,其共毒系数分别为814.4和1067.2。有机磷杀虫剂对氰戊菊酯的增效程度与其对α-乙酸萘酯羧酸酯酶(α-酯酶)的抑制能力呈极显著相关。异稻瘟净对马拉氧磷,TPP对久效磷也具有明显的增效作用,而异稻瘟净对乐果,TPP对氧化乐果则没有增效作用。