Thrips (Thysanoptera: Thripidae) mitigation in seedling cotton using strip tillage and winter cover crops

BACKGROUND: Thrips are the most consistent insect pests of seedling cotton in the southeastern United States, where symptoms can range from leaf curling to stand loss. In a 2 year study, thrips adults and immatures were sampled at 14, 21 and 28 days after planting on cotton planted with a thiamethoxam seed treatment in concert with crimson clover, wheat or rye winter cover crops and conventional or strip tillage to investigate potential differences in thrips infestations. RESULTS: Densities of adult thrips, primarily Frankliniella fusca (Hinds), peaked on the first sampling date, whereas immature densities peaked on the second sampling date. Regardless of winter cover crop, plots that received strip tillage experienced significantly fewer thrips at each sampling interval. In addition, assessment of percentage ground cover 42 days after planting showed that there was more than twice as much ground cover in the strip‐tilled plots compared with conventionally tilled plots. Correlation analyses showed that increased ground cover was inversely related to thrips densities that occurred on all three sampling dates in 2008 and the final sampling date in 2009. CONCLUSIONS: Growers who utilize strip tillage and a winter cover crop can utilize seed treatments for mitigation of early‐season thrips infestation. Copyright © 2010 Society of Chemical Industry     

The competence of four thrips species to transmit and replicate four tospoviruses

The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well-known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis , F. schultzei , Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi . Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body.     

基于生物防治的西花蓟马治理及思考

西花蓟马Frankliniella occidentalis(Pergande)是世界性的大害虫,对温室中蔬菜花卉造成巨大的危害。20世纪70年代后在世界范围内广泛而迅速地传播蔓延,近年入侵中国。西花蓟马对农药产生了广泛的抗性,使得生物防治一直作为其综合治理中的主导措施。本文综述了世界上西花蓟马生物防治的现状,以期为中国西花蓟马的治理提供一定的借鉴作用。     

西花蓟马的生物学习性观察试验

在温室内以粉色玫瑰为寄主植物观察并记录了西花蓟马的部分生物学习性,在恒温箱内记录了在15℃、20℃、25℃、30℃4个温度下各虫态的历期,并计算出发育起点温度和有效积温.     

10种杀虫剂对4种蓟马的毒力及对西花蓟马的田间药效评价

蓟马对农作物的危害逐年加重, 为筛选防治蓟马的高效低毒药剂, 采用叶管药膜法测定了10种常用药剂对4种蓟马的室内毒力, 并开展了田间防效试验。室内毒力测定结果表明, 6%乙基多杀菌素SC和10%虫螨腈SC对4种蓟马的毒力相对较高, 25%噻虫嗪WG和5%甲维盐EC的毒力较低, 西花蓟马和瓜蓟马对10种药剂的敏感性低于花蓟马和烟蓟马。田间药效结果表明, 25%噻虫嗪WG、10%溴虫氟苯双酰胺SC和4.5%高效氯氰菊酯EC对西花蓟马的防效较高, 药后7 d药效最高达到90%以上。综合室内毒力和田间药效试验结果, 推荐4.5%高效氯氰菊酯EC和10%溴虫氟苯双酰胺SC为防治蓟马的首选药剂, 可与25%噻虫嗪WG、48%多杀霉素SC、1.8%阿维菌素EC和10%吡丙醚SC等药剂轮换使用。     

防治西花蓟马药剂筛选试验

测定6种药剂在田问对西花蓟马防治效果，结果表明：2．5％菜喜悬浮剂、48％乐斯本乳油和0．3％印楝素乳油处理在施药3天后防效分别达到88．8％、86．0％和90．0％，7天后3种药剂防效为89．1％，91．0％；在大区试验中，筛选出的3种药剂对西花蓟马也有很好的防治效果，表明可以作为蔬菜上西花蓟马重发生时的应急防治药剂。     

不同温度下4株白僵菌对西花蓟马的致病力

本文测定了4株白僵菌在18、22、26、30、34 ℃ 5个温度下对西花蓟马成虫和若虫的毒力, 结果表明：白僵菌JMS、HS、MBb、RSB 4个菌株在这5个温度下对西花蓟马成虫均具有很高的致病力,绝大多数西花蓟马在5 d左右死亡,致死率均在97％以上,多数为99％～100％,致死中时为1.4～3.2 d,白僵菌RSB菌株对西花蓟马成虫的致死中时最短,在30 ℃下,仅为1.4 d。在各温度下供试菌种对西花蓟马若虫的致病力明显低于对西花蓟马成虫的致病力,其致死率一般在90％～99％,致死中时也相对较长。     

西花蓟马对不同寄主植物的选择及嗅觉行为反应

为比较西花蓟马Frankliniella occidentalis对不同寄主植物的选择性,本研究采用罩笼法观察了西花蓟马对8种不同蔬菜寄主植物(茄子、甘蓝、辣椒、黄瓜、莴笋、番茄、芹菜、香菜)的选择性,并使用“Y”形嗅觉仪评价了西花蓟马对不同蔬菜的嗅觉行为反应。结果表明,在8种不同蔬菜寄主植物中,西花蓟马对茄子、甘蓝的选择性最高;对芹菜和香菜的选择性较弱,表明西花蓟马对芹菜和香菜表现出忌避性。本研究结果为了解西花蓟马对不同寄主植物的选择提供理论依据。     

东亚小花蝽若虫对西花蓟马成虫的捕食作用

室内开展了东亚小花蝽二龄、四龄若虫对西花蓟马成虫的捕食功能反应与搜寻效应研究。结果表明,在26℃试验温度下其捕食功能反应均符合HollingⅡ型方程,东亚小花蝽若虫的捕食量随着猎物密度的增加而增加,搜寻效应随着猎物密度的增加而降低,捕食上限分别为9.2头和23.0头。     

土壤中花蓟马蛹的检测方法

本文对花蓟马属（Frankliniella）蛹期在土壤中存在的状态以及存在的时间进行了描述,并用直接镜检、干燥漂浮镜检、生物饲养检测等方法对土壤中蓟马蛹的检测方法进行了初步研究.生物饲养法能有效检出存在于土壤中的花蓟马蛹.     

入侵害虫西方花蓟马综合防治进展的概述

本文对西方花蓟马在我国适生性进行了简要的分析,概述了当前国内外西方花蓟马综合防治的研究进展,并提出了在我国控制该虫扩散蔓延的对策。     

温度对西花蓟马、花蓟马存活和繁殖的影响

在室内研究了19、22、25、28和31℃条件下两种蓟马在辣椒上的存活率、成虫寿命、繁殖力及生命参数,以揭示温度对入侵害虫西花蓟马Frankliniella occidentalis和本地害虫花蓟马Frankliniellaintonsa的影响。结果显示,在19～31℃范围内两种蓟马雌、雄成虫寿命均随温度的升高而缩短,内禀增长率随温度的升高而增大,西花蓟马和花蓟马皆是在31℃时最高,分别为0.1347和0.1822。两种蓟马的种群趋势指数及净增殖率与温度之间呈曲线关系。在相同温度条件下,西花蓟马在各温度下的存活率高于花蓟马,但内禀增长率低于花蓟马。西花蓟马的繁殖力、种群趋势指数及净增值率在22℃时最高,花蓟马在25℃时最高。两种蓟马对温度的适应能力不同,22℃是西花蓟马的最适温度,而25℃更适合于花蓟马。     

西花蓟马对不同颜色粘卡的嗜好及其诱虫效果

西花蓟马对14种不同颜色粘卡的嗜好及其诱虫量比较试验数据显示,颜色较浅的1号和4号黄色粘卡诱虫效果显著高于12号粘卡（市售黄板）.在测定颜色范围内,随黄色程度变浅诱集效果逐渐增强,蓝色粘卡从9号开始随颜色变深或变浅,诱虫效果均逐渐降低,黄色1号的诱虫效果最好,与黄色4号和蓝色9号粘卡的效果差异不显著.结果表明市场上出售的蓝色和黄色均不是诱集效果最好的颜色或亮度,以前没有黄色粘卡对西花蓟马诱集效果的报道.     

西花蓟马在宁夏的发生及防控措施

随着国际交流和经济活动的日益频繁,外来入侵有害生物西花蓟马(Frankliniella occidentalis)的传播扩散速度进一步加快,且分布广泛,是设施蔬菜等园艺作物的重要害虫之一。2003年发现该虫已入侵我国北京,随后在我国云南、山东、新疆等省份陆续发现,2012年在宁夏部分田间及大棚蔬菜中监测到西花蓟马。本文针对西花蓟马的入侵、发生、危害、形态特征以及监测与防治方法等方面进行了简要介绍,为预防、监测及有效阻断该虫的进一步扩散蔓延提供参考。     

3种环境友好型药剂对西花蓟马的室内毒力与田间防效

测定了3种杀虫剂对西花蓟马的室内毒力和田间防效。室内生物测定结果表明,多杀菌素、甲氨基阿维菌素苯甲酸盐、阿维菌素对西花蓟马成虫的LC50值为0.050～2.887mg/L,对西花蓟马若虫的LC50值为0.040～0.457mg/L;田间药效试验表明,田间防治西花蓟马时推荐使用剂量(防效>80%)分别为:2.5%多杀菌素悬浮剂30～60g/667m2,1%甲氨基阿维菌素苯甲酸盐乳油30～60g/667m2,1.8%阿维菌素乳油不可低于75g/667m2。     

三种药剂喷雾和灌根施药方式对西花蓟马的残留毒力

选取生产中常用的阿维菌素、噻虫嗪和螺虫乙酯,分别采用喷雾和灌根的方式施于甘蓝、甜椒和菜豆上,药后不同时间分别取3种作物上的老叶片及新生叶片,采用离心管法测定其对西花蓟马的残留毒力.结果表明,噻虫嗪灌根对西花蓟马的残留毒力最高,持效期长达一个月左右,可作为防治苗期西花蓟马的有效药剂和方法.     

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     

150亿孢子/g球孢白僵菌可湿性粉剂的研发及对西花蓟马的防治应用

为了研发靶标害虫为西花蓟马的球孢白僵菌杀虫剂，我们首先通过筛选、纯化和复壮获得对西花蓟马高效的真菌菌株；其次，对液-固双相发酵条件和发酵工艺进行优化；然后，改良了产品剂型和配方；最后对产品进行环境和毒性评价。结果显示该产品各项指标均符合国家标准。150亿孢子/g球孢白僵菌可湿性粉剂于2018年在国内获审批登记。喷施1800～3000 g/hm²对辣椒上西花蓟马的防效均为74%以上。推荐用量为2400 g/hm²。该产品的研发和获批登记为西花蓟马的生物防治奠定了坚实的基础。     

西花蓟马抗药性研究进展

西花蓟马是世界范围内蔬菜和花卉上的重要害虫之一,使用化学药剂是防治西花蓟马的主要手段,目前西花蓟马已对有机氯、有机磷、氨基甲酸酯、拟除虫菊酯、阿维菌素和多杀菌素等多种杀虫剂产生了抗药性。本文从抗药性现状、抗性机制和抗性治理等几个方面介绍了国内外有关西花蓟马抗药性的研究进展。