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在江苏射阳7块棉田观察调查的结果表明,小枕异绒螨的幼螨是棉蚜的重要天敌。幼螨发生量随田块和调查时期而不同。一般5月中下旬为发生高峰。5,6月间4次调查,平均每100头蚜虫有幼螨8.8头,最多61.6头,棉蚜平均被寄生率为6.5%,最高34.8%。影响幼螨发生量和棉蚜被寄生率的主要因素有:(1)旱改后连续旱作的年份,(2)茬口,(3)棉田用药治虫。旱作年份长,纯作棉和棉田用药少均对幼螨发生有利,棉蚜 相似文献
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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, 相似文献
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本文通过聚集度指标测定以及Iwar‘sM-x线性回归模型及其改进模型和Taylor’s幂回归模型分析,结果表明棉蚜,小枕异绒螨幼螨及其寄生棉蚜的个体间均相互吸收,空间格局的基本成分的系个体群,在低密度下,个体群均呈普通聚集格局,聚集速率均随种群密度的提高而下降,顺序为小枕异绒螨幼螨〉棉蚜〉被寄生棉蚜,但在一切条件下,其聚集强度均随种群密度的提高而加强,顺序为棉蚜〉小枕异绒螨幼螨〉被寄生棉蚜,本文末 相似文献
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玉米螟厉寄蝇初步观察 总被引:2,自引:0,他引:2
玉米螟厉寄蝇Lydella grisescens Robineau-Desvoidy是玉米螟的主要天敌之一。几年来我们作了一些观察试验,现把结果报导如下。 (一) 寄生率调查根据几年来的观察,第一代玉米螟幼虫被寄生率一般为30—40%,个别地块达80%,平均寄生率第一代为42%,第二代28.7%(详见表1)。在玉米螟严重发生的年份和集中发生的地块,被寄生率则更高。 相似文献
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茶足柄瘤蚜茧蜂引种研究 总被引:4,自引:0,他引:4
茶足柄瘤蚜茧蜂,于1983年由美国俄克拉何马州引到陕西省泾阳县,可寄生于麦二叉蚜、棉蚜、豆蚜、酸模蚜、禾谷缢管蚜、玉米蚜。1983~1986年在棉田、小麦田、杂草地及植物园温室分别放蜂21307、11508、2933和19562头。1987年调查放蜂结果:棉田棉蚜僵蚜出蜂172头中,未见引进蜂;小麦田禾谷缢管蚜和麦二叉蚜分别出蜂34和314头,各有引进蜂1头;杂草地豆蚜出蜂420头中,有引进蜂6头;在植物园温室扶桑与海桐上僵蚜率分别为49.3%和32.2%,全是引进蜂。对影响茶足柄瘤蚜茧蜂在陕西定殖的因素作了讨论。 相似文献
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棉蚜茧蜂[Lysiphlebia japonica (Ashmead)]对棉蚜不同虫态寄生选择的研究 总被引:1,自引:0,他引:1
研究表明,棉蚜茧蜂[Lysiphlebia japonica(Ashmead)]喜好寄生棉蚜2、3龄若蚜,寄生率分别为78.8%和87.2%;对4龄若蚜的寄生率为10.6%;1龄若蚜的寄生率仅为5%;棉蚜茧蜂一般不选择有翅蚜作为寄主。随着供蚜量的增加,未被寄生的蚜虫百分率从21.3%上升至63%;过寄生率从55.1%下降至8.37%;废卵率从53.1%降至7.9%。棉蚜茧蜂对健康棉蚜和被寄生过的棉蚜不能完全识别,存在过寄生现象。 相似文献
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石河子总场棉蚜棉叶螨重发原因分析及防治措施 总被引:1,自引:0,他引:1
棉蚜、棉叶螨是新疆北疆棉区的两种重要害虫。1991年、1994年棉蚜曾在石河子总场暴发成灾,造成棉花大幅减产,单产仅45~50kg/667m2,而且棉花后期拾花沾手,给采摘带来极大不便,并严重影响了棉花的品级。2001年7月,正是棉花花铃期,决定棉花产量的关键期,这时80%的有翅棉蚜向棉田迁飞而来,至7月19日已有4800hm2发生棉蚜,棉田有蚜株率达100%,百株有蚜25 000多头,益、害比严重失调,是继1994年以来迁飞蚜最为严重的1a。同年棉叶螨也严重发生。初步统计, 相似文献
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随着化学农药的大面积推广使用,棉蚜的抗药性问题变得越来越突出,结合使用生物防治法来延缓或治理棉蚜抗药性问题已迫在眉睫。本研究在常规管理棉田条件下,对不同作物混栽区苗期6种作物上棉蚜及其主要天敌的种群动态进行了调查。结果表明,西葫芦上的棉蚜种群数量最大(峰值,11016.7头/百株),其次是四季豆(峰值,6323.3头/百株),棉花、黄瓜、豇豆和甜瓜上的棉蚜则相对较少,且其种群动态发生具有一致性。6种作物上的主要天敌的种群发生都滞后于棉蚜的发生,并以寄生蜂的种群密度最大,且具有指数增长效应。在本试验条件下,西葫芦上棉蚜数量多,僵蚜基数大,是室内饲养寄生蜂的良好寄主。 相似文献
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棉田棉蚜种群动态及瓢虫对棉蚜种群数量的影响 总被引:5,自引:0,他引:5
根据新疆尉犁县4种棉花品种的棉田调查,利用棉蚜数量和时间进行回归分析,探讨其种群动态,应用棉蚜数量和瓢虫数量进行相关分析,研究棉田棉蚜种群与瓢虫种群的关系。结果表明,在不同品种的棉田中,棉蚜种群数量基本呈指数规律上升与下降。在尉犁县孔雀农场的中棉35和军棉1棉田中,从2001年5月31日至6月28日棉蚜种群数量呈指数增长,从6月28日至7月26日棉蚜种群数量呈指数下降。在尉犁县达西村的抗虫棉9和新陆中11棉田中,棉蚜种群数量开始发生和发生高峰期均比中棉35和军棉1推迟1周左右,其中抗虫棉9棉田的棉蚜发生高峰期数量最多,而新陆中11棉田的棉蚜发生期数量最少。在不同品种的棉田中,瓢虫是棉田棉蚜的主要天敌,对棉蚜起控制作用,它与棉蚜种群数量呈显著的跟随关系,发生期比棉蚜滞后1周左右。 相似文献
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北疆地区棉蚜对不同杀虫剂敏感度水平测定 总被引:4,自引:0,他引:4
为了解北疆不同地区棉蚜种群对不同类型杀虫剂的敏感度水平,科学指导北疆地区棉蚜的化学防治,利用FAO推荐的叶片浸渍法(1980)测定北疆地区4个棉蚜田间种群对4类杀虫剂的敏感性.结果表明,新农大种群对杀虫剂的敏感水平最高,不同类型杀虫剂的毒力大小顺序为:新烟碱类>有机磷类>抗生素类>拟除虫菊酯类.安宁渠种群较石河子种群更为敏感.石河子垦区内的两个不同种群对菊酯类处于相对敏感状态;对有机磷类产生了明显抗药性,147团种群对辛硫磷的相对抗性倍数为951.8倍,新湖农场种群更达到了1236.9倍;147团种群和新湖种群对啶虫脒亦产生了明显的抗药性,相对抗性倍数分别为134.4倍和270.0倍,但对吡虫啉的敏感度较高.石河子垦区应限制使用新烟碱类的啶虫脒和有机磷类杀虫剂,以减缓棉蚜抗性的发展. 相似文献
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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。 相似文献
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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. 相似文献
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依据棉蚜Aphis gossypii Glover测报的国家行业标准(GB/T15799.1995)及其测报调查的相关信息标准,利用分布式数据库SQL建立了棉蚜预测预报数据库,数据库主要包括早春木本寄主蚜虫调查、早春草本寄主蚜虫调查、苗期棉蚜消长情况调查、苗期棉蚜普查、伏期棉蚜系统调查、伏期棉蚜普查、棉田天敌系统调查、植保站信息和气象信息等12个数据表;利用Internet网络技术和网络开发软件,建立了浏览器/服务器应用程序结构体系,实现了棉蚜虫情数据维护、查询、统计、报表和打印等网络数据库管理和预测数据挖掘功能。棉蚜网络数据库的建立和浏览器/服务器应用程序结构体系的组建和实现,为棉蚜区域化预测预报和管理提供了有力的科学和技术支持。 相似文献
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H. Alejandro Merchán 《国际虫害防治杂志》2017,63(4):322-330
Duration of systemic pesticide activity under field conditions has wide implications for pest management. Our aim was to determine the duration of activity of systemic insecticides commonly used in cultivated tobacco (Nicotiana tabacum) by measuring the levels of insect infestations on field plots and effects on reproduction and survival of the green peach aphid (Myzus persicae) in controlled bioassays using field grown leaves. Plants were treated with different concentrations of two systemic neonicotinoid pesticides, imidacloprid and thiamethoxam, and grown in small field plots. Our results show that these materials are effective under field conditions against aphids for at least 13 weeks after transplant. Pesticides also affected aphid reproduction and nymph survival in bioassays, although some aphids survived on pesticide-treated leaves. We also observed that leaf age affected aphid survival. We showed that neonicotinoids were very effective against M. persicae, aphids are a useful organism to assess pesticide efficacy early in the growing season, but plant characteristics are more important than pesticide concentration in the second half of the growing season. 相似文献