转基因抗虫棉田棉蚜种群消长关键因素分析

为研究转基因抗虫棉田棉蚜种群动态的主要影响因素,在河北省南皮县采用罩网和开放式观测相结合的方法,以亲本常规棉为对照,对转Bt基因棉田和转Bt CpTI双价基因棉田棉蚜自然种群消长的关键因素进行了分析。与常规棉相比,单、双价抗虫棉对天敌捕食和寄生、病原物、风雨等生物和非生物因素对棉蚜种群的自然控制作用均未产生显著影响;各因素中,除自然死亡及未知因素死亡外,天敌捕食对棉蚜自然种群的控制作用最强,风雨的作用次之,天敌寄生和病原物的作用则较弱。单价抗虫棉田棉蚜的发育历期和产仔量均与亲本常规棉田无显著差异,但双价抗虫棉田棉蚜的发育历期较对照显著延长,产仔量则无显著差异。由此表明,捕食性天敌对单、双价抗虫棉田非靶标害虫棉蚜具有较好的自然控制作用,是影响棉蚜自然种群数量动态的关键因素;单、双价抗虫棉的抗蚜性存在一定差异。     

新疆棉田十一星瓢虫对棉蚜种群动态的影响

20世纪90年代以来，由于新疆棉花种植面积增加，使用化学农药后天敌控制能力下降[1]，使得棉蚜(Aphis gossypii Glover)暴发，成为棉花生产上的重要害虫。为加强天敌对棉蚜的控制作用，近几年新疆棉区对棉蚜不使用化学农药进行大面积防治，大多是在棉田出现中心蚜株时进行点片防治，棉虫基本上处于自然控制状态[2]。新疆尉犁县棉田十一星瓢虫((Coccinella undecimpunctata Linnaeus)种群数量大，繁殖速度快，是控制棉田棉蚜的主要天敌。本文报道在新疆棉田调查的结果。     

棉蚜自然天敌种群数量动态和控制蚜害的研究

调查了德州地区棉蚜主要天敌(瓢虫、草蛉、食虫蝽和蜘蛛类)5—8月份的种群数量动态。棉蚜天敌在不防治棉田内,虽能建立稳定的种群,但不能有效地控制蚜害;在化防田内由于喷药频繁,被杀伤严重,控制蚜害作用较小;在综防田内,基本上能建立自然种群,结合其它防治措施对控制蚜害的作用较明显,经济效益显著。     

棉花蚜螨繁殖率及棉蚜再猖獗

氰戊菊酯曾对棉蚜有极好的防治效果,而对棉叶螨防治效果极差。棉蚜抗药性的发展使药效发生了变化,近来的试验表明,该药对蚜虫药效很差,对伏蚜根本无效,１００和２００ｐｐｍ对棉蚜已属低浓度,可使其繁殖率增加４－８倍,在田间使用氰戊菊酯可形成大的棉蚜群体。在相同浓度下一般可抑制棉叶蚜群体,使药后存活很少的棉叶螨在种间竞争中处于劣势而使群体越来越小。氰戊菊酯的复配剂－丰收菊酯弥补了氰戊菊酯的不足,可同时控制蚜     

灭蚜菌和天力Ⅱ号对棉田蚜虫的防效试验

用ＥＢ－８２灭蚜菌２００倍液和天力Ⅱ号２０００倍液喷雾防治棉田蚜虫，喷后２、８天对棉蚜的防效分别为９０．６７％、８５．９４％和８６．２８％、９７．６５％；对棉长管蚜的防效均在９６％以上。ＥＢ－８２灭蚜菌对棉田常见捕食性天敌无伤害作用，天力Ⅱ号喷后天敌数量略有下降，喷氧化乐果的棉株上天敌全部死亡。     

棉田套种油菜招引天敌防治棉蚜

辽宁宜种植早熟陆地棉,棉田害虫以棉蚜为最主要。近廿多年来对棉蚜主要用化学防治。致使棉蚜天敌基数减少,像瓢虫、蝽蟓、蜘蛛、食蚜瘿蚊、蚜茧蜂……等,自然增殖缓慢,棉田一旦发生蚜虫就无法控制。 为了摸清棉田生境条件对蚜虫及其天敌种群数量变动的影响,1977年在锦西县黄土     

新疆棉区转Bt基因棉对棉田主要害虫及其天敌种群数量的影响

20 0 0～ 2 0 0 1年 ,在新疆棉区系统地研究了转Bt基因棉田主要害虫及其天敌的发生规律。结果表明 :转Bt基因棉对棉铃虫有良好的控制作用 ,发生高峰期百株落卵量和百株幼虫数量都显著低于常规对照 ,转Bt自控田和转Bt化防田棉蚜和棉盲蝽发生数量则显著高于常规棉对照田。在天敌方面 ,转Bt自控田和转Bt化防田较常规棉对照田 ,丽草蛉种群数量有所增加 ,而小花蝽和黑食蚜盲蝽等 5种捕食性和几种寄生性天敌数量都有所下降。转Bt基因棉田棉蚜和棉盲蝽等刺吸性害虫发生数量加重而多种天敌数量减少的趋势值得引起重视。鉴于新疆地区棉铃虫发生数量较低目前无需专门防治的特点 ,作者建议 :可以考虑推广农艺性状较好的常规棉品种并保护天敌 ,以达到控制害虫、丰产丰收的目的。     

自然天敌对苗期棉蚜控制的效果观察

棉蚜（ＡｐｈｉｓｇｏｓｓｙｐｐｉＧｌｏｖｅｒ）在棉花苗期普遍发生且危害严重。由于棉产区多年来频繁使用化学农药防治棉蚜，使棉蚜抗药性增强，同时大量杀伤天敌，造成环境污染，致使棉蚜更加猖獗在为害，对棉花产量影响很大．本试验是观察不同类型棉田棉蚜及其主要天敌的消长，以及天敌对棉蚜的控制效果，观察表明：棉田自然天敌对苗期棉蚜一般是可。控制其为害的；在生产活动中，要协调各项措施，尽量减少对天敌的影响，以提高其对棉蚜的自然控制能力。     

保护利用天敌防治棉蚜效果好

朝阳县十二台公社1978年种棉花一万亩,在棉蚜为害期间,有1280亩棉花常年没有用药剂防治,完全利用天敌控制住蚜害,1979年利用天敌控制蚜虫面积发展到3000多亩,棉花长势良好。保护、利用天敌防治棉蚜省工、省药效果好,为综合防治开辟了新途径。     

食蚜异绒螨韵初步观察

陕西棉蚜天敌十分丰富,有的年份可完全控制棉蚜为害。据我们多年调查,当棉蚜有翅蚜由其它寄主迁入棉田时,常常携带大量寄生绒螨,经鉴定,这些绒螨是绒螨科的无视异绒螨Allothrobium ignotum Willmann和肥绒螨Trombidium hyperi Nercammen Grandjean et al.。在我国上海、江苏、山西、陕西和湖北等省的棉田内均有分布。活动能力较强,在棉株上四处爬行、觅食,只要找到棉蚜,不论成蚜、若蚜或有翅蚜均可附体寄生,     

大豆蚜的系统最优控制研究

１９９３￣１９９６年作者以系统最优控制为技术原理,采用逐步逼近法和正交优化法,研究了豆田１１种可控因素对大豆蚜,天敌和产量的综合效应。根据既控虫增产又保护生态的原则,综合评价可控因素,提出大豆蚜系统最优控制：大豆与玉米同穴（４：１式）或间作（９：２式）、鲁豆４号６月１０日前后播种、１８００ｇ／ｈｍ＾２微肥拌豆种,Ｎ４５ｋｇ／ｈｍ＾２,Ｐ２Ｏ５ ６０ｋｇ／ｈｍ＾２、Ｋ２Ｏ１５０ｋｇ／ｈｍ＾２、有机肥     

Insects associated with the banana aphid <Emphasis Type="Italic">Pentalonia nigronervosa</Emphasis> Coquerel (Hemiptera: Aphididae) in banana plantations with special emphasis on the ant community

Ant attendance, well known behavior form towards aphid species was studied in case of the banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) populations in four plantations in the coastal area of Carmel (Israel), where the aphid is a major pest on banana. The study characterizes the ant community the extent of attendance and the natural enemies associate with the aphid. The ants and natural enemies were sampled on mats and suckers. The ant community in the plantations was also studied by using different ant baits. In addition, the ants’ impact on the density of the banana aphid population and the potential role of local natural enemies was evaluated in artificially infested potted banana plants set in the plantation with or without a glue barrier. More than 80% of the aphid colonies on the mats were attended by ants. Ten of the twelve ant species detected in the plantations were observed attending the banana aphid. Seventeen species of potential natural enemies of the aphid, mostly belonging to the families Syrphidae, Cecidomyiidae and Coccinellidae, were found in the aphid colonies. When ant attendance on infested potted banana plants was excluded, the number of natural enemies was higher, while the aphid density was lower, than recorded on the control plants. Our finding suggest that the ants, especially the invasive species, lower the pressure of natural enemies on the aphid population and but also probably remove large quantity of honeydew which is the source of the main damage caused by the banana aphid in the local plantations.     

合理施用选择性杀虫剂促进瓜绢螟天敌的控害作用

田间小区药效试验表明，乐斯本、氰戊菊酯、抑太保、Bt对葫芦科作物主要害虫瓜绢螟低龄幼虫都有很高的毒杀效果，其中抑太保、Bt效果较为缓慢。室内生测表明，乐斯本对寄生于瓜绢螟卵的赤眼蜂高毒，Bt则无毒。在秋黄瓜作物生长前中期连续施用乐斯本或Bt防治瓜绢螟，施药期间瓜绢螟均可得到较好的控制；但随着季节推移，在施用乐斯本的地块，瓜绢螟卵被寄生率很低，而在使用Bt的地块持续上升，高达70％以上；在停止使用杀虫剂12d后，施用乐斯本的地块瓜绢螟为害严重，而使用Bt的地块虫害被有效控制。结果表明，合理使用选择性农药可对天敌起到显著的保护和促增作用，并使瓜绢螟得到有效控制。     

Evaluation of food sprays and relay strip crops for enhancing biological control of bollworms and cotton aphids in cotton

Studies were conducted at the Texas Agricultural Experiment Station research farms located at Munday (1996 test) and Chillicothe (1997 test) to evaluate relay strip crops in combination with a food spray to enhance biological control of bollworms, Helicoverpa zea (Boddie), and cotton aphids, Aphis gossypii Glover, in cotton. The relay crops included fall plantings of hairy vetch, Vicia villosa Roth, and canola, Brassica napus L., and a spring planting of grain sorghum, Sorghum bicolor L. Cotton, Gossypium hirsutum L., was planted between the relay crops or was isolated from the relay crops. Treatments within the two cotton systems included an untreated check plot, a plot sprayed with sugar+yeast (food spray) during summer to attract and hold predator insects, a plot sprayed with biological ('soft') insecticides for bollworm and cotton aphid control (Bacillus thuringiensis and pymetrozine, respectively), and a plot sprayed with harsh insecticides for bollworm and cotton aphid control (zeta cypermethrin and dicrotophos or profonofos, respectively). A split-plot experimental design, with three replications, was used where whole plots included relay and isolated cotton systems and subplots were the four food/chemical treatments. Predator numbers were monitored with a vacuum sampler once a week in relay crops and cotton. Bollworms and cotton aphids were monitored visually once a week in cotton during July and August. Total predator numbers were higher in cotton adjacent to relay crops in 1996, but not in 1997. The food spray did not enhance attraction and retention of predators either year. Bollworm larval numbers were significantly higher in relay cotton, food spray plots in 1996. Bollworm larval numbers were similar in relay and isolated cotton, and larval numbers were significantly reduced only in the plot where zeta cypermethrin (harsh insecticide plot) was used. In 1996, cotton aphid numbers in the relay cotton system were significantly higher in the untreated check plots in relation to numbers in the food spray, soft insecticide, and harsh insecticide plots, which were statistically similar. In the isolated cotton system, aphid numbers were highest in untreated plots, intermediate in food spray and soft insecticide plots, and lowest in the harsh insecticide plots. Aphid numbers increased more rapidly in the harsh insecticide plots that had been treated previously for bollworm control. The food spray and pymetrozine treatments reduced cotton aphids more effectively in the relay cropping system than in the isolated cotton system. Bollworms and cotton aphids did not reach pest status in 1997. The combination of a relay cropping system with a food spray did not enhance predator numbers and did not aid in retention of predators in cotton during August. Sucrose in the food spray attracted high numbers of bollworms in 1996.     

麦套棉田苗期不施药保护天敌控制害虫的研究

棉蚜是棉田前期的主要害虫,过去一直应用农药防治。1904-1988年,在江苏省射阳县的麦套移栽棉田,进行了6月底前不用农药和施用农药防治棉蚜的对比试验,结果6月底前棉田不用农药防治棉蚜,天敌总数增加47.96％,中、后期害虫减少54.54％,蕾铃期虫害减少58.62％,玉米螟蛀棉茎数明显减少。棉花的生长、产量和品质与施用农药的棉田,差异不显著。作者认为麦套移栽棉田,在雨水调匀,棉株正常生长发育的年份,充分利用棉田天敌的作用,6月底前苗期不施农药防治蚜虫是可行的。     

赣南柑橘粉虱上升为主要害虫的原因及综合防控技术

柑橘粉虱（Dialeurodes Citri）在赣南以前是零星分布与为害,而近年来已逐渐上升为柑橘的主要害虫,其主要原因为农药更替、冬季清园不彻底、环境利于该虫成长、防治时期不当、喷药不全面、杀伤天敌等。为此提出以改善生态环境为基础的综合防控技术。     

保护利用蜘蛛防治水稻害虫的研究

水稻是湖南省的主要粮食,每年要用大量化学农药防治害虫。因此,作者在1975～1981年间,于长沙、湘阴等地进行了稻田蜘蛛保护和利用的室内外研究。结果证明,湖南省稻田蜘蛛资源丰富,并有良好的治虫效果。稻褐飞虱是它们的主要食物。通过保护,蜘蛛数量逐年增加,也保护了其它天敌,发挥了多种天敌联合治虫的作用,为综合防治提供了新内容,降低了农药用量,人畜安全,增产增收。     

小麦对麦长管蚜的耐害性及评估方法

为更有效地将耐害性用于小麦病虫害的绿色防控,该文就小麦对麦长管蚜的耐蚜性及其评估方法进行总结。具有耐蚜性的小麦受到一定数量蚜虫为害时,田间产量损失不明显,或能够通过生理生态途径补偿产量损失。耐蚜性不影响蚜虫的取食及生物学参数,对蚜虫进化压力小,因此田间表现更稳定。耐蚜小麦可以允许田间存在一定数量的蚜虫,这不仅可以减轻防治压力,还可以为天敌提供食物,有利于天敌的保护和利用,更符合有害生物绿色防控理念的核心。然而,目前抗麦长管蚜的小麦抗源鉴选主要是以蚜量为基础的抗生性和不选择性,耐害性被忽视。鉴于麦长管蚜田间蚜量与小麦产量(千粒重)损失率正相关,且峰值蚜量和小麦千粒重受损敏感期在小麦灌浆期重合,因此提出了以耐蚜值(千粒重损失率和灌浆期蚜情指标的比值)为依据计算耐蚜指数来评估小麦耐害性的方法,该方法可弥补抗源鉴选中忽视耐害性的不足,也能克服以田间千粒重损失率为依据评估耐害性时很难实现蚜量统一的不足,同时消除抗生性和不选择性带来的影响。