A survey of annual pesticide usage during the control of sheep ectoparasites in Northern Ireland, 1997

This is the third survey of control practices for ectoparasites on sheep farms in Northern Ireland, providing data comparative to those recorded in previous surveys in 1981 and 1988. Data relating to all aspects of ectoparasite control were collected from 210 farms representing 4% of the total sheep population. Quantitative data have been adjusted to provide accurate estimates of total pesticide usage. Since the previous survey in 1988, the number of sheep farms in Northern Ireland has increased by 10% to 11 692 with a consequent 39% increase in sheep population to 2.9 million. Despite this level of expansion, the total quantity of organophosphorus compounds used for ectoparasite control has remained approximately constant at 7–8 tonnes. The report considers that compulsory sheep‐dipping, prescribed since 1970 and revoked in 1993, impacted significantly on subsequent ectoparasite control practices and consequent pesticide usage. During 1997, approximately 20% of sheep farmers relied on alternative methods to control ectoparasites, including injectable formulations of avermectins and pour‐on formulations of insect growth regulators and pyrethroids. Dipping formulations containing pyrethroid compounds, which accounted for <1% of treatments in 1988, increased to 9% in 1997. Previously, regulatory sheep‐dipping periods were specified during the autumn months, which tended to increase dipping frequency. The majority of farmers dipping sheep during the summer strictly for blowfly maggot (Diptera: Calliphoridae) control were required to perform additional compulsory sheep‐dipping during the autumn. Withdrawal of compulsory sheep‐dipping has allowed farmers to synchronise dipping practices to control the major ectoparasites of sheep at a single dipping occasion. An estimated 7.5 × 10⁶ litres of surplus dipwash required disposal and there were approximately equal numbers of farmers disposing dipwash immediately after sheep‐dipping or on occasions up to and including subsequent dipping. The decline in the number of farmers who allowed dipwash to run‐off into soakaways or surrounding soil observed in 1988 continued in 1997. The majority of farmers used tractor‐operated pumps to dispose of dipwash into slurry tanks for subsequent disposal onto permanent pasture. © Crown copyright 2000. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd.     

几种药剂对甜菜叶螨的田间防治效果

【目的】筛选对甜菜田叶螨有较好防治效果的化学药剂及配比。【方法】采用随机区组的试验方法,试验设7个药剂处理和1个清水对照,通过田间药效试验,采用田间喷雾的药效方法,于药后1、3和7 d定点取样调查各处理小区的叶螨数量,评价供试药剂处理对叶螨的防除效果及对甜菜的安全性。【结果】药后7 d,22%阿维·螺螨酯悬浮剂4 000倍液处理、25%三唑锡可湿性粉剂10 000倍液处理、10%阿维菌素可分散粒剂1 500倍液处理、73%炔螨特乳油2 000倍液处理、240 g/L螺螨酯悬浮剂4 000倍液处理对甜菜叶螨的防效分别达93.35%、93.51%、93.38%、91.80%和89.87%。【结论】筛选出5种对甜菜叶螨具有较好防治效果的杀螨剂,药后7 d防治效果均达89.87%以上,对甜菜安全,可在甜菜叶螨防治中合理轮换使用。     

10种新型药剂对苹果叶螨的田间药效

笔者在河南三门峡市苹果产区,进行了10种药剂17个处理防治苹果叶螨的田间药效试验。结果表明,各药剂处理对苹果叶螨均有较好的防治效果。其中10%浏阳霉素750倍、1500倍、1%甲氨基阿维菌素9000倍、1 8%阿维菌素2500倍、5000倍、50%宝路可湿粉剂2000倍、毙百虫500倍处理第1～14天,3%莫比朗1000倍第1、3天,2000倍第1、3、7天,2 5%菜喜1000倍、2000倍、15%哒螨灵第3～14天,1%甲氨基阿维菌素12000倍、毙百虫1000倍第3天的校正防效均在95%以上。植物源农药2 5%烟碱苦参碱500倍、1000倍第1天的校正防效较低,分别为73 2%、62 2%,第3天为87 5%、87 8%,第7天为93 5%、91 9%,第14天为89 2%、88 5%,毙百虫1000倍第1、3、7、14天的防治效果分别为93 8%、96 8%、94 6%、92 0%,均取得了较好的防治效果。5%卡死克2000倍的防治效果较差,第1、3、7、14天的防治效果分别为77 4%、84 9%、86 0%、71 8%。     

黄河三角洲贝壳堤岛土壤甲螨群落种类组成及区系分析

为保护和修复黄河三角洲贝壳堤岛的生态系统,于2008年5—10月对其土壤甲螨进行了调查。结果显示,共获得标本2 457头,隶属于30科46属52种,其中优势种有3个:覆盖头甲螨、盛若甲螨和大洋上罗甲螨。对39个已知种进行区系分析,华北区与华中区重叠率最高(89.7%),其次是与东北区和华南区,再次是与西南区和蒙新区,与青藏区重叠率最低(0)。黄河三角洲贝壳堤岛土壤甲螨在中国动物地理区划中的归属类型多样,多数甲螨分布较广。     

Active ingredient contents of ‘me-too’ registered abamectin products and differences in their efficacy onTetranychus cinnabarinus

Many agrochemical companies in Turkey purchase generic active ingredients (a.i.) and, by way of ‘me-too’ registration, sell pesticides under different brand names. Farmers and researchers often claim that these products are ineffective. In order to determine the a.i. content and efficacy of me-too registered abamectin-based products, we studied seven (in 2004) and ten (in 2005) products, which were chosen based on their availability and high market share. Differences in both efficacy and a.i. contents were observed in the products investigated in the study, but making speculative statements that could affect all me-too registered products based on our investigations of only 17 abamectin-based samples is not realistic. Timectin® was found to be statistically less effective onTetranychus cinnabarinus in both laboratory and greenhouse trials than all other tested products. Furthermore, Timectin was determined to have 69.8% less a.i. than in its product specifications. Our findings make it clear that grower complaints about the qualities of agricultural pesticides are based on actual chemical inadequacies of formulated pesticides. Analysis of the a.i. should be carried out as part of regular market inspection in order to determine whether agricultural pesticides comply with their product specifications. In this way growers will be provided with good quality but inexpensive products.     

蜂蟹螨(Varroa destructor)对福化利抗药性及其防治的研究

建立培养皿药膜法进行蜂蟹螨福化利(Fluvalinate)抗药浓度检测方法。分别以福化利浓度为0、12.5、25、50、100mg/L进行台湾5处蜂场蜂蟹螨抗福化利剂量调查,经回归分析,计算LC50之浓度介于23.75～79.25mg/L之间,比意大利抗性螨385～857mg/L仍低很多,显示抗药性尚未大幅增加。以隔落螨法防治蜂蟹螨平均每日可捕捉44.7～49.1只。比较隔落螨法、割雄蜂蛹加隔落螨法、蚁酸加隔落螨法、福化利防治法的效果,当蜂蟹螨密度不高时,可采用隔落螨法或加割雄蜂蛹方式进行防治,蜂蟹螨密度高时,可先以福化利、蚁酸进行1～2次防治,再配合隔落螨法,将可达到长期防治效果。     

苹果单叶片山楂叶螨实验种群的建立与消亡

【目的】研究山楂叶螨种群在苹果幼苗单叶片上建立、扩展的过程,以期明确山楂叶螨由个体到种群的发展机理和整体趋势。【方法】选择3年生盆栽矮化红富士苹果幼苗,分别单叶接螨1,3和5头,观察单叶山楂叶螨种群繁殖和扩散情况及叶片的变化,记录35d该螨由个体发展为种群,导致叶片焦灼的整个过程。【结果】山楂叶螨在室内,6月份15～17d可完成1代,35d内完全发生2个世代。在苹果单叶片上,卵占种群优势数量,其在不同位置叶片分布为中部>上部>下部,雌成螨的数量分布表现为上部>下部>中部。初始接螨量越大,叶片上种群数量越多,其种群扩张速度越快,为害越严重,叶片提前干枯。当单叶接螨量达5头,接种(6.6±1.5)d后向其他叶片扩散,(14.6±2.5)d后全株布满蛛丝及叶螨,仅(20.4±1.1)d达4级为害状,叶片全株焦灼。【结论】山楂叶螨应在叶片害斑不明显时及早防治,关键控制初始螨量,当单叶虫源基数达5头时应密切关注其繁殖动态。     

Economic impact of Wheat streak mosaic virus in the Texas High Plains

Wheat streak mosaic virus, vectored by the wheat curl mite Aceria tosichella Keifer, is a major limiting factor in wheat production in the Texas Panhandle. It is the most frequently encountered virus in the region, affecting both shoot and root biomass, and consequently it can drastically reduce both forage and grain yield, and water-use efficiency of the plant. In light of the continuing decline of water levels in the Ogallala Aquifer, its effect on water-use efficiency has significant implications for irrigated fields, especially with regard to energy costs for pumping water. This article estimates the potential economic losses from the virus infection. To achieve this objective, partial budgeting techniques, based primarily on data from field experiments, were used. Results indicate that Wheat streak mosaic virus causes grain and forage yield losses that significantly affect profits from wheat production. In addition, irrigated wheat producers are more negatively affected by the disease due to the economic losses from reduced water-use efficiency of infected plants. The economic insights from this article provide important implications for wheat management and research priority-setting.     

A new tray-type arena to mass rear Neoseiulus baraki, a predatory mite of coconut mite, Aceria guerreronis in the laboratory

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is an important predatory mite of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) and attempts are now being made to evaluate the effectiveness of augmenting N. baraki to control coconut mite in the field. These studies require a steady supply of N. baraki in large numbers. One major constraint of the existing method to mass rear N. baraki on Tyrophagus putrescentiae Shrank (Acari: Acaridae) in a closed arena without a water barrier was frequent contamination of cultures by other mites. This paper describes the development of an efficient method to mass rear N. baraki in the laboratory with less monitoring and relatively minimal contaminants. Three box-type arenas and a tray-type arena were tested to mass rear T. putrescentiae. Mites were successfully developed on two box-type arenas and the tray-type arena, but the production (2197 mites per tray in 4 weeks) of T. putrescentiae was significantly higher on the tray-type arena. A 110-fold increase of T. putrescentiae was achieved in tray-type arenas in 4 weeks. None of the box-type arenas could be maintained more than 5 weeks without acarine and fungal contaminations. N. baraki could be successfully reared on the tray-type arena at least for 6 weeks. More than 4800 mites per tray, a 240-fold increase was achieved in 5 weeks when T. putrescentiae was added at 3-week intervals. Advantages and disadvantages of the new method are described.