四种药剂防治茶小绿叶蝉的药效

在成虫期 6 6 6 7m2 用 70 %杀螟丹 5 0g ,5 8%吡虫啉—杀螟丹混剂A( 1∶4 ) 5 0g,2 2 %吡虫啉—噻嗪酮混剂 ( 1∶4 ) 5 0g ,兑水 75kg,蓬面喷雾 ,对茶小绿叶蝉类药后 7天虫口减退率达 84 5 %～ 93 5 % ,2 0天内维持在 91 6 %以上。 1 0 %吡虫啉用药量偏低 ( 1 0g 6 6 6 7m2 ) ,2 0天的药效仍有 77 2 % ,具速效和持效期长的特点。     

吡虫啉与杀虫单对水稻飞虱和螟虫联合作用研究

在室内测定了吡虫啉与杀虫单混配对水稻褐飞虱Ｎｉｌａｐａｒｖａｔａｌｕｇｅｎｓ和二化螟Ｃｈｉｌｏｓｕｐｐｒｅｓｓａｌｉｓ的联合作用,并进行了田间试验。结果表明吡虫啉与杀虫单复配对褐飞虱、二化螟有相加和增效作用,以配比1∶20～1∶40增效作用最好。吡虫啉对二化螟有较高的毒杀作用,以点滴法和稻茎浸渍法测得其致死中量为0 8873μｇ/头和0 3743ｍｇ Ｌ,分别是杀虫单的5 168倍和2 19倍。田间试验表明,在室内试验中ＣＴＣ值较高的配比(1∶22～1∶39)的药剂在田间对水稻飞虱和螟虫均有较好的防治效果,防治稻飞虱的防效在94 7%以上,防治二化螟的效果在55 6%～90 6%之间,防治三化螟的效果在55 13%～95 41%之间,防治稻纵卷叶螟的效果在81 6%以上。     

毒死蜱与噻嗪酮、吡虫啉混用防治稻飞虱和二化螟田间试验

20 0 2年在安徽省庐江县 4次田间试验结果表明 ,防治 3代和 4代稻飞虱 (Sogatellafurcifera(Horvath)和Nilaparvatalugens(St l) ) ,667m2 用 48%毒死蜱乳油 41 67mL +1 0 %吡虫啉可湿性粉剂 2 0g的处理 7d后防治效果分别为 93 0 3 %和 92 67% ,毒死蜱 5 2 0 8mL +2 5 %噻嗪酮可湿性粉剂 5 0g分别为92 79%和 95 2 2 %。防治 2代和 3代二化螟Chilosuppressalis(Walker) ,667m2 用毒死蜱 41 67mL +吡虫啉2 0g的处理 1 6d后防治效果分别为 73 2 2 %和 80 43 % ,毒死蜱 5 2 0 8mL +噻嗪酮 5 0g分别为 76 81 %和84 80 %。建议交替轮换使用以上混剂及剂量 ,并掌握在稻飞虱低龄若虫高峰期和二化螟卵孵高峰期施药 ,可有效防治稻飞虱和二化螟。     

麦长管蚜和禾谷缢管蚜对吡虫啉敏感性的比较研究

采用麦穗浸渍法在室内测定了麦长管蚜Macrosiphumavenae(Fabricius)和禾谷缢管蚜Rhopalosiphumpadi(L .)对吡虫啉可湿性粉剂和乳油的敏感度。结果表明 ,禾谷缢管蚜对吡虫啉的敏感度是麦长管蚜的 3～ 4倍 (基于LC50 的比较 )。在北京、河南、江苏、湖北、四川等地同浓度的吡虫啉对禾谷缢管蚜的防治效果要好于麦长管蚜 (特别是在低浓度时尤为明显 )。依据我国不同省份小麦穗蚜的优势种不同 ,建议用吡虫啉防治小麦穗蚜时 ,在南方麦区 ,禾谷缢管蚜为优势种的麦田 ,吡虫啉用药量为 15～ 3 0g(a.i) hm2 ;北方麦区 ,以麦长管蚜为优势种的麦田 ,吡虫啉的用药量应大于 3 0g(a.i) hm2 。     

无公害水稻生产的病虫草调控技术及其效应的研究

利用无公害农药和农业措施防治水稻主要病虫草试验结果表明,井·腊芽、井冈霉素和多抗霉素在水稻分蘖末期和孕穗末期各喷施1次,对纹枯病防效达75.16%～94.27%,优于化学杀菌剂三唑酮;春雷霉素和灭瘟素在叶瘟病发生初期及破肚期、齐穗期各喷施1次,对叶瘟防效为50.54%～72.67%,穗瘟为76.66%～87.42%,与化学杀菌剂三环唑相当.3种无公害农药在二化螟和稻纵卷叶螟1～2龄幼虫期使用,苏云金杆菌防效优于化学杀虫剂杀虫双,皂素·烟碱和苦参碱与杀虫双相当;皂素·烟碱和苦参碱在稻飞虱1～2龄若虫期使用,药后3～30d防效均在70%以上,低于化学杀虫剂吡虫啉.在水稻移栽前耕地2次,再配合施用适量的未腐熟有机质或人工除草,能控制杂草发生和提高产量.采用无公害农药和农业措施防治水稻病虫草,产量较常规化防区略有增加,稻谷中农药残留量较化防区低,符合绿色食品卫生指标要求.     

吡虫啉与高效氯氰菊酯复配对橄榄星室木虱的增效作用

测定了吡虫啉与高效氯氰菊酯对橄榄星室木虱的毒力及其最佳复配比例。结果表明 ,高效氯氰菊酯与吡虫啉按 2 :3的比例复配 ,增效作用最为明显 ,共毒系数达到 2 6 7。按此比例配成 5 %的制剂 ,对田间橄榄星室木虱有较好的防治效果 ,15 0 0倍、2 0 0 0倍、2 5 0 0倍药液 1天后的防效达 37.88- 6 5 .14 % ,3天达 70 .19-89.37% ,2 1天达 92 .36 - 10 0 %。     

应用马尔可夫链法预测晚稻稻飞虱发生程度

根据化州市 1 979～ 1 999年 2 1年晚稻稻飞虱主害代发生程度的时间序列资料 ,应用马尔可夫链预测法对该市 2 0 0 0年和 2 0 0 1年稻飞虱发生程度进行了预测 ,结果与大田实际发生情况完全一致。对1 985～ 1 999年的历史资料进行回检 ,符合率为 96.7%,可对晚稻稻飞虱的发生程度进行超长期预测。     

一种防治稻飞虱的喷雾辅助装置

介绍一种防治稻飞虱喷药时的辅助装置,使用该装置可在确保药剂防治效果的前提下提高工效,并节省用药量。     

释放天敌瓢虫和施用化学农药吡虫啉对麦田蚜虫的控制效果评价

以常规防治农药甲胺磷做对照,比较高效低毒化学农药吡虫啉和天敌昆虫瓢虫对田间麦蚜的防治效果。结果表明,施用10%吡虫啉可湿性粉剂300ghm2药后5d和10d的防效分别为15.1%和31.1%,对麦蚜防效理想。释放天敌昆虫瓢虫后5d和10d的防效分别为-347.6%和-171.7%,防效差,这是由于释放天敌后的强降雨所致。     

拌种吡虫啉残留对麦长管蚜实验种群的影响

为探明吡虫啉拌种后在下一代小麦籽粒中的吡虫啉残留对麦长管蚜Sitobion avenae (Fabricius)实验种群的影响, 用60%吡虫啉悬浮种衣剂与小麦籽粒按照2, 4, 6和8 g/kg的比例进行处理, 在室内条件下采用超高效液相色谱-串联四级杆液质联用法对收获后的小麦籽粒进行残留分析; 并通过室内生命表方法, 研究麦长管蚜取食上述剂量吡虫啉拌种处理收获后的小麦籽粒所长幼苗后的各项生命参数。结果表明： 收获的小麦籽粒中吡虫啉残留量随拌种剂量的增加而增加, 以8 g/kg处理后收获的籽粒中残留量最高, 为0.0290 mg/kg。随着吡虫啉残留量的增加, 麦长管蚜发育历期缩短, 有翅蚜率和产仔量增加, 但与对照相比均未达到显著差异(P=0.392＞0.05); 不同剂量吡虫啉拌种处理的麦长管蚜净生殖率、 内禀增长率、 周限增长率比对照偏高, 而种群加倍时间、 平均世代周期比对照偏低, 但均未达到显著性差异（P=0.406）。结果说明小麦籽粒中的吡虫啉微量残留对麦长管蚜生长发育无显著不利影响, 但对其生殖能力具有一定的促进作用。     

Interaction effects between Beauveria bassiana and imidacloprid against Thrips tabaci (Thysanoptera: Thripidae)

The onion thrips, Thrips tabaci Lindeman is a major pest of many horticultural crops in many parts of the world. The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin and imidacloprid are used for the control of the onion thrips. The potential interactions between the fungus and the chemical against the onion thrips adults were evaluated in a laboratory and two greenhouse bioassays. The laboratory bioassay was a leaf dip bioassay for a mixture of B. bassiana and imidacloprid. The first greenhouse bioassay was a topical application of a mixture of the fungus and the chemical while the second bioassay was a drenching application of imidacloprid and a topical application of B. bassiana. In all bioassays, the combined application resulted in higher percentage mortalities than either B. bassiana or imidacloprid alone. In the laboratory bioassay, the highest mortality of 97% was achieved by using B. bassiana at the field rate with imidacloprid at 1/10th the field rate relative to 88%, 94%, 21% for B. bassiana alone, imidacloprid alone and the control, respectively. In the first greenhouse bioassay, the highest mortality of 80% resulted from the combined application of B. bassiana and imidacloprid at field rates compared with 55%, 75%, and 22% for B. bassiana alone, imidacloprid alone and the control, respectively. In the second greenhouse bioassay, the combined application of both control agents at field rates resulted in 85% mortality compared with 52%, 83%, and 18% for B. bassiana alone, imidacloprid alone and the control, respectively. The interaction effect between the two control agents was additive except when B. bassiana at 1/2 field rate was mixed with imidacloprid at 1/10th field rate in the laboratory bioassay, where the interaction was antagonistic. The above results indicate that combining imidacloprid with B. bassiana might reduce the rate of the insecticide application while enhancing the efficacy of the biological control agent.     

Selective insecticide-induced stimulation on fecundity and biochemical changes in Tryporyza incertulas (Lepidoptera: Pyralidae)

The use of selective insecticides in rice, Oryza sativa L., fields often causes resurgence of nontarget pest insects. This study was conducted to investigate the effect of two selective insecticides, buprofezin and imidacloprid, on Tryporyza incertulas (Walker), a nontarget pest. After larval feeding on rice plants treated with each insecticide, fecundity, ovary protein content, and titer of juvenile hormone III (JHIII) in the resulting female moths were determined with 'Xiushui 63' rice susceptible to T. incertulas and 'Zhendao 2' moderately resistant to T. incertulas. The fecundity of females developed from larvae that fed on the insecticide-treated Xiushui 63 plants was stimulated compared with that of moths from larvae that fed on rice plants that were not treated with either insecticide. There was no stimulating effect in females from larvae that fed on insecticide-treated Zhendao 2 plants. The weight of fourth instars (final instars) that fed on the insecticide-treated Xiushui 63 rice plants was significantly greater than that of control, increasing by 50.3 and 46.7% for 60 and 112.5 g (AI) ha(-1) buprofezin, and by 23.7 and 19.5% for 15 and 37.5 g (AI) ha(-1) imidacloprid treatments, respectively. Ovary protein content in adult females developed from larvae that fed on the rice treated with the high dose of buprofezin was significantly higher than that in control. For the high and low doses of imidacloprid during the second instar, and the low dose of imidacloprid during the fourth instar, JHIII titers in female adults were also significantly higher than that in control, increasing by 152.81, 90.52, and 114.19%, respectively.     

Fecundity in twospotted spider mite (Acari: Tetranychidae) is increased by direct and systemic exposure to imidacloprid

The effect of imidacloprid on fecundity in twospotted spider mites, Tetranychus urticae Koch, was investigated in laboratory experiments using individual females on bean leaf discs. Mites were directly exposed to spray formulations of imidacloprid or fed on discs cut from a systemically treated bean plant. Imidacloprid-treated T. urticae produced 10-26% more eggs during the first 12 d of adult life and 19-23% more during adulthood compared with a water-only treatment. Increased egg production occurred immediately after exposure and lasted for about 15 d in sprayed mites. In mites exposed to imidacloprid by ingestion, increased egg production was not apparent until after 6 d and lasted until about day 18. Longevity was significantly greater in mites that ingested imidacloprid but not in sprayed mites. The significance and importance of imidacloprid-stimulation of fecundity in T. urticae to pest management in crop systems like hops, which routinely use this insecticide, is discussed.     

5种杀虫剂对滇东白背飞虱种群的毒性及其田间药效

【目的】为持续有效防控白背飞虱,研究云南东部白背飞虱种群对常用5种杀虫剂的敏感性及药剂的田间防治效果。【方法】采用室内稻茎浸渍法测定白背飞虱种群对5种杀虫剂的敏感性,同期通过田间小区试验评价5种杀虫剂对白背飞虱种群的防治效果。【结果】与敏感种群比较,噻虫嗪、噻嗪酮、吡虫啉、吡蚜酮和毒死蜱对滇东白背飞虱种群的LC_(50)分别为0.208、0.459、0.608、3.108、1.256 mg·L~(-1),抗性倍数分别为2.2、10.4、5.6、6.5、5.3倍;白背飞虱对噻虫嗪无抗性,对吡虫啉、吡蚜酮和毒死蜱为低水平抗性,对噻嗪酮为中等水平抗性;5种杀虫剂药后1、5和10 d对白背飞虱种群的田间防控效果均有显著差异。除了吡蚜酮外,其他药剂的防效均在80%以上,其中以吡虫啉和噻嗪酮的持续期较长,药后10 d仍在90%以上;噻虫嗪和吡虫啉药后1和5 d的防效达90%以上;吡蚜酮药效在供试药剂中防效最低,在64.88%～77.82%之间。【结论】滇东师宗白背飞虱种群对噻嗪酮为中等水平抗性,对吡虫啉、吡蚜酮和毒死蜱均为低水平抗性,对噻虫嗪无抗性,田间防控效果以吡虫啉和噻嗪酮为最好。建议滇东稻区可以使用吡虫啉和噻嗪酮药剂防控白背飞虱,注意控制吡蚜酮的使用次数与用量。     

Laboratory evaluation of the toxicity of systemic insecticides for Control of Anoplophora glabripennis and Plectrodera scalator (Coleoptera: Cerambycidae)

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most serious nonnative invasive forest insects discovered in North America in recent years. A. glabripennis is regulated by federal quarantines in the United States and Canada and is the subject of eradication programs that involve locating, cutting, and chipping all infested trees. Other control methods are needed to aid in eradication and to form an integrated management program in the event eradication fails. We conducted laboratory bioassays to determine the toxicity of two systemic insecticides, azadirachtin and imidacloprid, for potential control of A. glabripennis and the cottonwood borer, Plectrodera scalator (F.) (Coleoptera: Cerambycidae), a closely related native cerambycid. Larvae of both cerambycid species were fed artificial diet with dilutions of azadirachtin or imidacloprid for 14 wk. Both insecticides exhibited strong antifeedant effects and some toxicity against A. glabripennis and P. scalator larvae. For A. glabripennis, the highest larval mortality at the end of the bioassay was 60% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (1.6 ppm). For P. scalator, the highest larval mortality at the end of the bioassay was 100% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (160 ppm). At 14 wk, the LC50 values for P. scalator were 1.58 and 1.78 ppm for azadirachtin and imidacloprid, respectively. Larvae of both species gained weight when fed diet treated with formulation blanks (inert ingredients) or the water control but lost weight when fed diet treated with increasing concentrations of either azadirachtin or imidacloprid. In a separate experiment, A. glabripennis adults were fed maple twigs treated with high and low concentrations of imidacloprid. A. glabripennis adult mortality reached 100% after 13 d on twigs treated with 150 ppm imidacloprid and after 20 d on twigs treated with 15 ppm imidacloprid. There was no visible feeding by A. glabripennis adults on twigs treated at the higher imidacloprid rate, and feeding was significantly reduced for adults placed on twigs treated at the low imidacloprid rate compared with adults on untreated twigs. In summary, imidacloprid and azadirachtin had both antifeedant and toxic effects against A. glabripennis and P. scalator and have potential for use in management programs. Based on our results, the delivery of high and sustained insecticide concentrations will be needed to overcome the antifeedant effects and lengthy lethal time for both larvae and adults exposed to these insecticides.     

Imidacloprid susceptibility survey and selection risk assessment in field populations of Nilaparvata lugens (Homoptera: Delphacidae)

Imidacloprid has been used for many years to control planthopper Nilaparvata lugens (St?l) (Homoptera: Delphacidae) in China. To provide resistance assessment for the national insecticide resistance management program, we collected a total of 42 samples of the planthoppers from 27 locations covering eight provinces to monitor their dose responses and susceptibility changes to imidacloprid over an 11-yr period (1996-2006). Results showed that most field populations maintained susceptibility from 1996 to 2003 except for a population from Guilin, Guangxi, in 1997, which showed a low level of resistance to imidacloprid. However, surveys conducted in 2005 indicated that 16 populations from six provinces quickly developed resistance with resistance ratios ranging from 79 to 811. The data collected in 2006 revealed that the resistance levels in 12 populations collected from seven different provinces decreased slightly (RR = 107-316), except the Tongzhou population (Jiangsu Province), which developed 625-fold resistance. Dominant and intensive use of imidacloprid in a wide range of rice, Oryza savita L., growing areas might be a driving force for the resistance development. Migration of the insect also significantly boosted the resistance levels due to extensive and intensive use of imidacloprid in emigrating areas and continuous postmigration sprays of the chemical. In addition, laboratory resistance selection using imidacloprid showed that resistance ratio increased to 14-fold after 27 generations, suggesting that quick resistance development might be associated with more frequent applications of the insecticide in recent years.     

Effect of neonicotinoid synergists on entomopathogenic nematode fitness

In previous greenhouse and field studies, the neonicotinoid insecticide imidacloprid interacted synergistically with five entomopathogenic nematode species against five scarab species. Two other neonicotinoids, thiamethoxam and acetamiprid, showed a weaker interaction with nematodes in scarab larvae. Entomopathogenic nematodes have the potential to recycle in hosts after inundative applications, thereby increasing the persistence of nematodes and insect control. Thus we investigated the effect of neonicotinoids on nematode fitness after tank mixing and after combined applications. Tank mixing only had a negative effect on nematode survival and infectivity in a few nematode–insecticide combinations and only if both insecticide concentration and exposure time were several times higher than typical for field applications. Combined application of nematodes with imidacloprid generally had no negative effect on the percentage of scarab cadavers producing progeny or the number of nematode progeny emerging per cadaver. In experiments with a synergistic increase in scarab mortality, the total number of progeny in combination treatments was up to four times higher than in nematodes only treatments. Similarly, nematode populations in soil from combination treatments were 13.2 times greater than for nematodes only treatments at 28 days after treatment. Combined imidacloprid–nematode applications did not affect the pathogenicity or infectivity of the nematode progeny. Combining thiamethoxam with nematodes had no negative effects on nematode reproduction in the majority of treatments. However, due to the weaker interaction of thiamethoxam and nematodes on scarab mortality, the total number of nematode progeny per treatment generally did not increase compared with nematodes only treatments. The demonstrated tank mix compatibility of imidacloprid and nematodes improves the feasibility of combining these agents for curative white grub control. The positive effect of imidacloprid on nematode reproduction after combined application may increase the likelihood of infection of white grubs by subsequent generations of nematodes, thereby improving their field persistence and biological control potential.     

Insecticidal sugar baits for adult biting midges

The mixing of an insecticide with sugar solution creates an oral toxin or insecticidal sugar bait (ISB) useful for reducing adult insect populations. The ability of ISBs to kill the biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), a vector of bluetongue virus, epizootic hemorrhagic disease and vesicular stomatitis viruses, was tested. The commercial insecticide formulations (percentage active ingredient) tested included bifenthrin, cyfluthrin, deltamethrin, permethrin, dinotefuran, imidacloprid, thiamethoxam and spinosad. Mortality rates were determined for various concentrations of commercial formulations (0.01, 0.05, 0.1, 1, 2 and 3%) and observed at 1, 4, 10 and 24 h post‐exposure to the ISB. In the first set of assays, laboratory‐reared midges were fed sugar ad libitum and then exposed to insecticide‐treated sugar solutions to measure mortality. The second assay assessed competitive feeding: midges were provided with a control sugar solution (10% sucrose) in one vial, and a sugar and insecticide solution in another. Pyrethroid treatments resulted in the greatest mortality in the first hour at the lowest concentrations and spinosad consumption resulted in the least mortality. Biting midges were not deterred from feeding on the 1% ISB solutions despite the presence of an insecticide‐free alternative source of sugar.     

Response of arthropods associated with the canopy of common beans subjected to imidacloprid spraying

Abstract:   Imidacloprid, the first neonicotinoid of potential use in agriculture, became an important agent for controlling leafhoppers, aphids, thrips and whiteflies. The use of this compound was extended to common beans in Brazil, a crop of great socio-economic value throughout Latin America, and the aim of the present work was to assess the temporal effectiveness and environmental safety of this insecticide to the arthropod community associated with the canopy of this crop plant. Thirty six species of phytophagous and detritivorous species were collected, as well as 37 species of predators and parasitoids. However, there was no significant impact of imidacloprid on species richness. In contrast, the insecticide significantly decrease the arthropod abundance for over a 30-day period. This impact is probably a reflection of the effect of this insecticide on Thrips tabaci and Caliothrips brasiliensis (Thysan., Thripidae) the most frequent and abundant species present in the area, and important pests of common beans in Brazil. Among the other most frequent taxa (present in over 50% of the samples), Araneae (predators) and the green leafhopper Empoasca kraemeri (Hom., Cicadellidae), another important bean pest in Brazil, were not significantly affected by imidacloprid, unlike the thrips species T. babaci and C. brasiliensis which showed decreased population levels until 8 days after imidacloprid application.     

Impact of sequential exposure of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and imidacloprid against susceptible and resistant strains of <Emphasis Type="Italic">Musca domestica</Emphasis>

Insecticide resistance in the housefly Musca domestica is hampering pest management. However, entomopathogens, possibly in combination with insecticides, may have control potential against resistant houseflies. This study investigates the combination of the entomopathogenic fungus Beauveria bassiana and the neonicotinoid insecticide, imidacloprid against a susceptible and a resistant housefly strain, respectively under laboratory conditions. The fungus and insecticide were tested alone and in combinations at LC₃₀. Significant and synergistic interactions between B. bassiana and imidacloprid were observed with increased mortality rates of the combined treatment as compared to individual treatment in housefly strains 772a (susceptible) and 766b (resistant). Significant differences in the GST and P450 activities for both strains were found. Female 766b flies caused 15- to 237-fold increases in gene expression of xenobiotic response genes for B. bassiana and 23- to 120-fold changes for imidacloprid. The combination of B. bassiana and imidacloprid caused significant synergistic interaction when applied against two housefly strains irrespective of order of application. The effect was highest when the insecticide was applied first. The resistant housefly strain had elevated detoxification enzymes and higher expression of detoxification genes, but showed the same level of susceptibility to the combined fungus/insecticide treatment as the susceptible strain.