茶小绿叶蝉类化学防治指标的计算

一、化学防治指标概念 现阶段,在茶园抚育管理中,对害虫使用化学防治还是必不可少的重要措施。特别是在茶小绿叶蝉类繁殖高峰期,使用化学防治控制其危害尤为重要。但是也不能泛用,否则不仅得不偿失,而且更为严重的是将有可能使茶叶农药残留量超标,危及人们的健     

茶小绿叶蝉成虫天敌—螯蜂

茶小绿叶蝉螯蜂是寄生于茶小绿叶蝉成虫的一种体外寄生蜂。茶小绿叶蝉主要为害茶树的嫩芽、嫩叶,严重影响苯叶的产量及品质,是茶叶生产上的一种重要害虫。目前在防治此虫的手段中,许多茶区主要是采用化学防治,采一次茶喷二次农药,有的在喷农药后,有效期还没有过期,即进行采茶,严     

茶假眼小绿叶蝉防治方法

介绍茶假眼小绿叶蝉的形态特征、寄主范围、生活习性、为害特点和防治方法,以减轻茶假眼小绿叶蝉对茶树的为害,减少农药残留。     

菊马乳油防治茶小绿叶蝉试验

我区茶树主要害虫茶小绿叶蝉类常给茶叶生产带来很大损失。1989年7月,笔者在本所应用中国农科院植保所研制的20％菊马乳油对茶小绿叶蝉类进行了防治试验,现将试验结果整理如下:     

浅析茶小绿叶蝉的防控技术与措施

为了确保生态农业发展和食品质量安全,逐步推广以生态、无公害为核心的茶小绿叶蝉综合防治体系,阐述了农业防治、物理防治、生物防治的核心作用,尽量避免使用化学防治方法,着力构建茶小绿叶蝉的绿色防控体系,确保茶叶品质可靠与绿色安全。     

滇南茶小绿叶蝉综合防治技术与应用

作者根据1988～1993年对云南省南部西双版纳和思茅地区茶园中的茶小绿叶蝉的生物生态学特性研究结果,遵照IPM的要求设计了:①以采代治,②试用新防治历,③按防治指标防治,④生物防治,4个分项防治措施,并进行了分项小区试验和综合利用这些防治措施的综合防治试验。试验结果表明:设计的4项单一防治措施和综合防治措施,在对茶叶产量和质量无影响,而又能控制茶园小绿叶蝉为害的情况下,经济和人力投入都比传统的化学防治方法少,而且降低了茶叶中农药残留量。     

昭平县茶小绿叶蝉的发生特点及其防治

茶小绿叶蝉是昭平县茶园的主要害虫,近年来发生面积逐年增加,为害程度逐年加重。通过对茶小绿叶蝉发生特点的调查,总结其发生规律,分析其偏重发生的原因,提出了防治意见,为该虫的防治工作提供指导和借鉴作用。     

茶假眼小绿叶蝉发生为害特点调查研究

通过多点系统调查,探讨了茶假眼小绿叶蝉在福建主要茶区发生规律及为害特点。揭示了该虫百叶虫量与百梢虫量及虫梢率的相关性,比较了茶梢不同部位该虫着卵的比率。为茶假眼小绿叶蝉预测预报及防治提供了理论依据。     

联苯菊酯·噻虫啉对茶小绿叶蝉的防治效果

通过开展田间试验,验证40％联苯菊酯·噻虫啉悬浮剂对茶树主要害虫茶小绿叶蝉的防治效果.结果 表明,该药剂对茶小绿叶蝉防效较高,制剂用量在15～20 g/667m2的防治效果可达90％以上,且无明显药害,对茶树生长无不良影响.     

MeSA诱导茶树抗叶蝉取食效应的DC-EPG分析

用可视直流刺探电位技术(DC-EPG)记录试虫在3h 内呈现的各种EPG波型。共明确7种波型,根据这些波型确定15个描述叶蝉取食行为的EPG参数,以评判茶树抗叶蝉取食特性。与未诱导茶苗(CK)上叶蝉刺吸行为相比,在0.2、0.4和0.8mmol/L MeSA诱导24h的茶苗上,总刺探次数增加,即n_(ck) =8.30±1.13,n_(0.2)=13.25±3.95,n_(0.4)=15.01±2.68,n_(0.8)=34.50±7.56;非取食刺探时间明显延长,即NP_(ck)=110.97±5.2min, NP_(0.2)=128.39±6.76min, NP_(0.4)=148.35±6.14min, NP_(0.8)=131.94±10.75min;韧皮部取食时间显著减少,即E_(ck)=52.90±2.22min, E_(0.2)=9.08±2.6min, E_(0.4)=8.87±1.44min, E_(0.8)=15.89±2.21min。3个MeSA处理剂量相比较,0.4mmol/L的诱导效应最明显。24h与48h 诱导时间相比,24h的效应较显著。茶树被诱导之后,对叶蝉的取食适合度明显下降,表明产生了一定程度的抗性。     

Weed infestation and tea growth under various weed management methods in a young tea (Camellia sinensis[L.] Kuntze) plantation

A field experiment was conducted in the low country of Sri Lanka, during the period 1994–1995 to investigate the severity of weed infestation and tea growth in relation to weed management methods in newly established tea ( Camellia sinensis [L.] Kuntze). Manual weeding (hand and slash weeding) at various intervals was compared with various herbicides, with or without mulching. Weed control with herbicides was superior to that of hand weeding at 6-week intervals or more. Weed control with oxyfluorfen at 0.29 kg ai ha⁻¹ + paraquat at 0.17 kg ai ha⁻¹ or glyphosate at 0.99 kg ai ha⁻¹ + kaolin at 3.42 kg ha⁻¹ were superior. Plots unweeded for 12 weeks or more produced significantly greater ( P  < 0.05) weed biomass than plots unweeded for 6 weeks. Although the least weed dry weight ( P  < 0.05) and the greatest number of weed species were recorded with hand weeding at 2 week intervals, there was no particular benefit on tea growth when compared with hand weeding at 6 and 12 week intervals. Inter row mulching in chemically treated plots was more favorable for tea growth than no mulching, while living weed cover in unmulched slash weeded plots suppressed tea growth. A combination of mulching and herbicides, particularly oxyfluorfen and paraquat, followed by hand weeding at least every 6–8 weeks was considered the most appropriate weed management system for young tea.     

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     

LED风吸式杀虫灯对有效范围内茶小绿叶蝉虫口动态的影响

为明确LED风吸式杀虫灯对茶小绿叶蝉Empoasca onukii的防治效果,室内测定诱虫光源对茶小绿叶蝉卵和若虫生长的影响,温室内测定不同灯高和不同灯距组合下杀虫灯诱捕的茶小绿叶蝉数量,并计算杀虫灯对茶小绿叶蝉成虫的有效控制范围、诱杀中距离、诱杀黄金距离,并通过2年田间试验比较杀虫灯有效控制范围内不同灯距处、有效控制范围外茶小绿叶蝉成虫数量。结果显示:诱虫光源对茶小绿叶蝉卵和若虫的生长无显著影响,若虫生长历期为18.5 d,存活率为46.85%。随着灯距和灯高的增加杀虫灯对茶小绿叶蝉的诱捕量下降,灯高20～40 cm时,杀虫灯对茶小绿叶蝉的平均有效控制范围、平均诱杀中距离和平均诱杀黄金距离分别为58.17、30.41和23.86 m。茶园内灯距5 m处,茶小绿叶蝉成虫数量率先达到5个灯距中的最大值,不同灯距下茶小绿叶蝉成虫数量随时间推移而呈现出显著差异,虫口峰期时灯距25 m内的茶小绿叶蝉成虫数量为灯距120 m处的49.5%～64.4%。表明LED风吸式杀虫灯可通过诱杀茶小绿叶蝉成虫显著抑制其诱杀黄金距离内茶小绿叶蝉的成虫数量。     

Oncopsis alni (Schrank) (Auchenorrhyncha: Cicadellidae) as a Vector of the Alder Yellows Phytoplasma of Alnus glutinosa (L.) Gaertn.

Alder yellows phytoplasma was detected by PCR in Alnus glutinosa trees in the Palatine and Mosel areas of Germany. The restriction profiles obtained by TaqI and AluI digestion of a PCR amplified ribosomal DNA fragment from this phytoplasma and a periwinkle isolate of alder yellows from Italy (ALY) could not be distinguished while elm yellows isolates from Europe and North America led to different fragment patterns. Different restriction profiles for ALY and the German alder phytoplasma were obtained by TruI digestion of a non-ribosomal DNA fragment. Phloem feeding insects were collected from infected alder trees. Phytoplasmas of the elm-yellows group were detected by PCR in psyllids and the leafhopper Oncopsis alni. These pathogens were indistinguishable from the phytoplasma found in alder. Only O. alni was able to transmit the pathogen to healthy alder seedlings. Thus, it is the first insect known to transmit this phytoplasma. This leafhopper could be responsible for the ubiquitous infection of Alnus glutinosa due to its close association with alder and its wide distribution in Europe.     

琼凹大叶蝉精子发生及精子超微结构

昆虫精子超微结构在不同类群间变异较大, 在昆虫分类、种群进化研究及系统发育分析中具有重要意义。研究叶蝉科昆虫精子发生及精子超微结构, 可为叶蝉科及头喙亚目系统发育分析提供更多特征依据。本研究采用光学和电子显微镜技术, 观察了琼凹大叶蝉Bothrogonia qiongana Yang et Li的精子发生和精子超微结构。精子形成时期, 精子细胞内高尔基复合体形成精子顶体; 线粒体融合衍变为线粒体衍生物; 中心粒产生轴丝。单层微管结构围绕精子各组成部分, 在精子成熟后消失, 对精子细胞伸长起关键作用。成熟精子细长、线状, 头部顶端由绳状物质连接形成梳状精子束。顶体圆锥状, 具有顶体腔, 末端延伸出2条突起插入细胞核顶端。细胞核近柱状, 末端平截, 侧缘凹陷, 通过片层状中心粒侧体与鞭毛线粒体衍生物连接。尾部鞭毛由1条9+9+2型轴丝, 2条对称线粒体衍生物, 2条较短副体, 2条细小附结构及鞭毛中心物质组成。琼凹大叶蝉副体横切椭圆形、长度较短仅出现在鞭毛起始区, 与角顶叶蝉亚科昆虫差异较大。结合已报道头喙亚目类昆虫, 我们推断副体结构可为叶蝉科及头喙亚目系统发育分析提供有用的特征。     

Comparison of kinetic properties of a hydrophilic form of acetylcholinesterase purified from strains susceptible and resistant to carbamate and organophosphorus insecticides of green rice leafhopper (Nephotettix cincticeps Uhler)

A hydrophilic form of acetylcholinesterase (AChE) was purified from N-methyl carbamate susceptible (SA) and highly N-methyl carbamate-resistant (N3D) strains of the green rice leafhopper (GRLH), Nephotettix cincticeps Uhler. Both of purified AChE from SA and N3D strains displayed the highest activities toward acetylthiocholine (ATCh) at pH 8.5. In the SA strain, the optimum concentrations for ATCh, propionylthiocholine (PTCh), and butyrylthiocholine (BTCh) were about 1 × 10⁻³, 2.5 × 10⁻³, and 1 × 10⁻³ M, respectively. However, in the N3D strain, substrate inhibition was not identified for ATCh, PTCh, and BTCh to 1 × 10⁻² M. The K_m value in the SA strain was 51.1, 39.1, and 41.6 μM and that in the N3D strain was 91.8, 88.1, and 85.2 μM for ATCh, PTCh, and BTCh, respectively. The K_m value in the N3D strain indicated about 1.80-, 2.25-, and 2.05-fold lower affinity than that of the SA strain for ATCh, PTCh, and BTCh, respectively. The V_max value in the SA strain was 70.2, 30.5, and 4.6 U/mg protein and that in the N3D strain was 123.0, 27.0, and 14.5 U/mg protein for ATCh, PTCh, and BTCh, respectively. The V_max value in the N3D strain was 1.75- and 3.15-fold higher for ATCh and BTCh than that in the N3D strain. However, it was 1.13-fold lower for PTCh. The increased activity of AChE in the N3D strain is due to the qualitatively modified enzyme with a higher catalytic efficiency. The bimolecular rate constant (k_i) for propoxur was 27.1 × 10⁴ and 0.51 × 10⁴ M⁻¹ min⁻¹ in the SA and N3D strain and that for monocrotophos was 0.031 × 10⁴ and 2.0 × 10⁴ M⁻¹ min⁻¹ in the SA and N3D strain. AChE from the N3D strain was 53-fold less sensitive than SA strain to inhibition by propoxur. In contrast, AChE from the N3D strain was 65-fold more sensitive to inhibition by monocrotophos than AChE from the SA strain. This indicated negatively correlated cross-insensitivity of AChE to propoxur and monocrotophos.