Pyrethroid resistance in the predacious mite Amblyseius barkeri1

By successive generations of exposure to Ripcord (cypermethrin) at concentrations ensuring about 50% mortality, a cypermethrin-resistant strain of Amblyseius barkeri has been selected, with a resistance factor of 73. The strain showed cross resistance to other pyrethroids.     

Biological control of Frankliniella occidentalis on ornamental plants using predatory mites1

The results of four experiments on biological control of Frankliniella occidentalis on flowering Saintpaulia ionanfha and one on pelargonium are presented. Three species of predatory mites were used for the experiments: Amblyseius barkeri, and two soil-dwelling species Hypoaspis aculeifer and H. miles. Three releases each of 15 H. miles per saintpaulia plant at weekly intervals did not have any effect on the pest population. In two experiments on saintpaulia, 10 females of H. aculeifer per plant were released weekly for a period of 10 weeks. The increase of thrips population was slowed down for some weeks and population peaks were diminished. However, this treatment failed to keep the pest at a low level. In one experiment, 15 A. barkeri per saintpaulia plant were released weekly for 10 weeks. Thrips population dynamics was slowed down for about 4 weeks, but again the treatment failed to keep the pest at a low level. In one experiment on pelargonium, 15 A. barkeri per plant were released fortnightly for 10 weeks. An effect was obvious in both replicates. Pest populations hardly increased on the plants treated with the biocontrol agent but increased significantly in the controls. The reasons for these results and differences are discussed. The suitability of these three species for production and use as biocontrol agents is discussed.     

Integrated thrips control on glasshouse cucumbers1

Thrips are among the most dangerous pests of glasshouse cucumbers in Poland. The most frequent species, causing the greatest damage, are Frankliniella occidentalis and Thrips tabaci. The integrated programme of glasshouse cucumber protection against thrips consists of prophylactic treaments, use of the predators Amblyseius barkeri and Neoseiulus cucumeris, and agrotechnical measures.     

山楂叶螨对胡瓜钝绥螨的吸引作用研究

采用两侧吸引作用试验测定天敌胡瓜钝绥螨Amblyseius cucumeris Oudemans在田间对山楂叶螨的搜索和控制能力。结果表明:山楂叶螨不同螨态对胡瓜钝绥螨均有显著的吸引作用,排泄物对胡瓜钝绥螨没有明显的吸引作用。山楂叶螨对胡瓜钝绥螨的这种吸引作用说明胡瓜钝绥螨在田间具有自动搜索山楂叶螨的能力,可用于山楂叶螨的生物防治。     

Research on and use of biological methods of pest control in glasshouse crops in Poland1

In 1966/1967, the predatory mite Phytoseiulus persimilis and the hymenopteran parasite Encarsia formosa were introduced into Poland. This introduction led to extensive research on the principles and practical use of biological and integrated programmes of pest control in glasshouse crops. Additional species were later introduced (Macrolophus costalis, Amblyseius mckenziei, Neoseiulus cucumeris, Cycloneda limbifer, Cryptolaemus montrouzieri), and research was also undertaken on local species such as Aphidoletes aphidimyza and Aphidius matricariae. At present, after 25 years of research, modem and effective mass rearing of natural enemies has been organized, and they are applied over 600 ha of glasshouse crops. For correct development of biological methods in glasshouses, new introductions, research, and mass rearing of new species are necessary.     

胡瓜钝绥螨室内种群生命表研究

研究观察了以皮氏叶螨为食物时胡瓜钝绥螨的发育和繁殖情况,建立了室内种群生命表,以期为海南省儋州市引进该螨进行繁殖和应用提供科学依据。试验结果表明,24～28℃为胡瓜钝绥螨种群增长的最适温度,30℃以上的高温对其发育、存活和繁殖具有抑制作用。根据海南儋州地区的气候特点和皮氏叶螨危害作物的微生态环境,可以考虑将该螨作为皮氏叶螨捕食性天敌加以引进和应用。     

巴氏钝绥螨对椭圆食粉螨的捕食效能

在实验室RH85%、5个常温(16、20、24、28℃和32℃)条件下,研究了巴氏钝绥螨的雌成螨、雄成螨、若螨对椭圆食粉螨的捕食效能。结果表明:各个温度下的功能反应均属于HollingⅡ型。温度相同时,雌成螨的捕食能力最大,若螨其次,雄成螨的捕食能力最弱。温度对各螨态的捕食能力有一定的影响,在试验温度范围内,各螨态对椭圆食粉螨的捕食能力(a/Th值)随温度升高而增大,28℃时捕食能力最大。在椭圆食粉螨密度固定时,巴氏钝绥螨的平均捕食量随着其自身密度的提高而逐渐减少。     

胡瓜钝绥螨对柑桔红蜘蛛的控制作用

胡瓜钝绥螨作为一种活体天敌,具备了活体天敌控害的一般规律。研究结果表明,在按一定益害比释放胡瓜钝绥螨的桔园,柑桔红蜘蛛一般出现“无峰型“、“双峰型“和“单峰型“的消长规律。出现柑桔红蜘蛛高峰期,主要是在释放胡瓜钝绥螨后的种群建立期间和越夏后。胡瓜钝绥螨对绣壁虱控制作用不稳定。     

栗真绥螨和黄瓜新小绥螨对西方花蓟马初孵若虫功能反应的比较

于人工气候箱（23±1℃、RH70%±5%、光照（D∶L=16h∶8h）条件下,在菜豆叶片制作的叶碟上,比较了栗真绥螨与黄瓜新小绥螨对西方花蓟马初孵若虫的功能反应。结果表明：黄瓜新小绥螨和栗真绥螨对西方花蓟马初孵若虫的功能反应均符合HollingⅡ型模型,分别为Na=0.763×Nt/（1＋0.152Nt）和Na=0.257×Nt/（1＋0.032Nt）,对西方花蓟马初孵若虫的攻击率分别为0.763和0.257,处理时间分别为0.199d和0.125d,日最大捕食量分别为5.0头和8.0头。     

胡瓜钝绥螨控制柑桔害螨研究

利用胡瓜钝绥螨控制柑桔全爪螨和锈壁虱 ,研究结果表明 ,在不同生态区域胡瓜钝绥螨释放量为 90万头 /hm²,30d后防效可达 85%～95% ,控制害螨期长达 6个月 ,减少农药使用量40%～60%。生防园果实商品价值提高约1000元/667m²。本文还对在不同树龄、不同生态条件下使用捕食螨的适期、比例及配套技术等进行了研究     

Isoforms of the heteropteran Nezara viridula ecdysone receptor: protein characterisation, RH5992 insecticide binding and homology modelling

BACKGROUND: Certain bisacylhydrazine compounds such as tebufenozide (RH5992) have been shown to act as order‐specific insecticides. Their compatibility with predatory Heteroptera, which are used as biological control agents, has also been demonstrated. However, the molecular mode of action of these ecdysone agonists has not been explored in a heteropteran, much less one that is a significant agricultural pest, such as Nezara viridula. RESULTS: Alternatively spliced ligand‐binding regions of the N. viridula ecdysone receptor were expressed, purified and characterised by 2D gel analysis, mass spectrometry, homology modelling and competitive binding of a bisacylhydrazine insecticidal compound (RH5992) and various ecdysteroids. Ligand binding by the two splice isoforms was indistinguishable, and relative affinities were found to occur in the order muristerone A > ponasterone A > 20‐hydroxyecdysone > inokosterone > RH5992 > α‐ecdysone. CONCLUSION: The predicted difference in amino acid sequence between the ligand‐binding domains of the N. viridula ecdysone receptor splice variants was verified by mass spectrometry. Both splice variant isoforms exhibit a greater affinity for the bisacylhydrazine insecticide RH5992 than do the other hemipteran ecdysone receptors characterised to date. Their affinities for a range of ecdysteroids also distinguish them from the ecdysone receptors of other Hemiptera characterised thus far. Homology models of both N. viridula receptor isoforms provide further insight into the bisacylhydrazine‐ and ecdysteroid‐binding properties of these receptors, including their similar affinity for 20‐hydroxyecdysone and the postulated pentatomomorphan moulting hormone makisterone A. Copyright © 2011 Society of Chemical Industry     

Side effects of botanical insecticides on predatory mite Amblyseius andersoni (Chant)

The effects of the botanical insecticides Biopiren plus, Piresan plus and Neemazal T/S on the predatory mite Amblyseius andersoni (Chant) were tested under laboratory, semi-field, and field conditions. The tests carried out in the laboratory allowed detection of the direct toxicity on eggs and females as well as the effects on fecundity, whereas semi-field trials assessed their residual toxicity. In laboratory and semi-field tests, pyrethrins, particularly Piresan plus, proved to have the highest toxicity with E value, concerning both female mortality and fecundity, of 100% and 45%, respectively. The same product tested in the field only caused a significant reduction in the phytoseiid population shortly after the treatment. The relevant escape rate registered in semi-field tests could explain the lack of phytoseiid eradication in the field after treatment with pyrethrins.     

5种杀虫剂和黄瓜新小绥螨对棉田朱砂叶螨的协调防治

为协调使用杀虫剂及害虫天敌,本文测定了阿维菌素、印楝素、苦参碱、除虫菊素和吡虫啉5种常用杀虫剂分别与天敌黄瓜新小绥螨(原名胡瓜钝绥螨)对棉田朱砂叶螨的联合防治效果。结果表明:1.8%阿维菌素EW(1∶8 000)处理6d后释放黄瓜新小绥螨对朱砂叶螨的防治效果最佳,20d后相对防治效果高达96.63%;其次是0.3%印楝素EC(1∶250)处理7d后释放黄瓜新小绥螨,1d和20d后防效分别为59.7%和90.16%;0.5%苦参碱AS(1∶2 000)处理6d后释放黄瓜新小绥螨,20d后相对防治效果达到82.65%。本研究为朱砂叶螨可持续防控提供了可选方案,为延缓抗药性产生提供了研究思路。     

黄瓜绿粉病病原鉴定及其发生规律研究

黄瓜绿粉病是温棚蔬菜上一种新病害,由绿藻门集球藻(Palmellococcus sp.)引起。藻孢卵圆形、长椭圆形、淡绿色、单胞、大小3.39～12.38μm×1.06～10.82μm,表面有山脊状隆起,是一种依附于体表的气生性自养生物。该病害多在1～3月份发生,与湿度密切相关。每日温棚中RH不低于80%,RH100%在12h以上,藻孢生长旺盛;当中午有1h以上RH低于70%时,藻孢的发育受到抑制。凡能增大温棚湿度的栽培措施如灌水、密植等因素均能加重发病。黄瓜品种抗病性无明显差异。     

巴氏钝绥螨发育起点温度与有效积温

在15℃、20℃、25℃、30℃、35℃五种恒温、湿度72%,光照L∶D=12∶12的人工气候箱中,测定巴氏钝绥螨的发育历期.结果表明:随温度升高,发育历期逐渐缩短.巴氏钝绥螨卵、幼螨、前若螨、后若螨、产卵前期、世代的发育起点温度分别为18.07℃、12.65℃、13.66℃、13.25℃、15.85℃、11.90℃;有效积温分别为:11.57、10.95、23.08、20.90、24.20和126.87日·度.根据有效积温法则预测巴氏钝绥螨在南昌地区的发生代数为21代.     

水稻锯齿叶矮缩病毒对褐飞虱生长发育和生殖的影响

为明确水稻锯齿叶矮缩病毒（rice ragged stunt virus,RRSV）对褐飞虱Nilaparvata lugens生长发育和生殖的影响,分别比较带毒褐飞虱与未带毒褐飞虱的若虫发育历期、成虫寿命、性比、翅型及产卵量,并利用实时荧光定量PCR（real-time quantitative PCR,RT-qPCR）技术分析RRSV侵染后褐飞虱体内卵黄原蛋白（vitellogenin,Vg）与其受体（vitellogenin receptor,VgR）以及海藻糖代谢途径中相关基因表达量的情况。结果显示,带毒褐飞虱的若虫历期显著高于未带毒褐飞虱的若虫历期,分别为17.56 d和15.90 d;带毒褐飞虱的成虫寿命、雌虫比例和短翅比例均高于未带毒褐飞虱的,但两者间均无显著差异;带毒褐飞虱较未带毒褐飞虱单雌日产卵量显著提升,分别为11.26粒和6.45粒;带毒褐飞虱的Vg、VgR和海藻糖转运蛋白基因（trehalose transporter,TRET）表达量均显著高于未带毒褐飞虱的。表明RRSV侵染会显著延长褐飞虱若虫发育历期,同时可能通过上调Vg、VgR以及TRET的表达量以促进褐飞虱生殖。     

胡瓜新小绥螨对B型烟粉虱的控制能力

为明确胡瓜新小绥螨Neoseiulus cucumeris Oudermans对烟粉虱Bemisia tabaci Gennadius的控害潜能,在（26±1）℃、相对湿度65%±5%、光周期16L：8D条件下,研究了各螨态胡瓜新小绥螨对不同发育阶段烟粉虱的捕食作用。结果表明,胡瓜新小绥螨幼螨期较短,不取食烟粉虱,其他不同螨态的胡瓜新小绥螨可捕食除4龄若虫和成虫以外的其他各虫态的烟粉虱,捕食功能反应符合HollingⅡ型;胡瓜新小绥螨雌成螨对烟粉虱卵的日捕食量最大（8.5粒/雌）,对烟粉虱3龄若虫的日捕食量最小（2.1头/雌）;雌成螨对烟粉虱卵具有较高的瞬间攻击率（0.038）和寻找效应（0.025）。研究表明,胡瓜新小绥螨对烟粉虱卵及低龄若虫的捕食能力较强,是烟粉虱发生初期的有效天敌。     

工厂化生产胡瓜钝绥螨防治柑橘全爪螨的应用效果

经过多年探索,研制成功捕食螨胡瓜钝绥螨的人工饲料配方及其大量繁殖方法,建立起年生产能力110亿～120亿头捕食螨的工厂化生产基地,生产成本降至3元/万头。1998年应用于脐橙园防治全爪螨,释放捕食螨后30～120d,防效近100%。2000年应用于芦柑园、蜜柚园防治全爪螨,释放后80～90d,防效分别达93.8%、98.1%。1a释放2次,控制期可达6个月。     

Influence of environmental factors on conidial germination and survival of Sphaeropsis pyriputrescens

Sphaeropsis pyriputrescens is the cause of Sphaeropsis rot in apples and pears. In this study, effects of temperature, wetness duration, relative humidity (RH), dryness, and interrupted wetness duration on conidial germination of the fungus were evaluated. Conidial germination and germ tube elongation occurred at temperatures from 0°C to 30°C. The optimum temperature for germination and germ tube elongation appeared to be 20°C, at which a minimum wetness period of 5 h was required. Conidia germinated at RH as low as 92% after 36 h at 20°C, but not at 88.5% RH. The effect of dry periods on germination depended on RH. Conidial germination at 85% RH was higher than that at 25% RH within a 4-h dry period, after which time no difference was observed. Less than 10% conidia germinated after a 10-day dry period at both 20°C and 28°C. Conidial germination decreased as the wetness duration prior to dryness increased. Conidia wetted for 6 h prior to dryness died within a 1-h dry period. After a 12-h dry period, no or few conidia germinated at 25% RH, whereas 3% to 10% of the conidia germinated at 85% RH and no further decrease was observed as the dry period increased. The results contribute to our understanding of conditions required for conidial germination of S. pyriputrescens and infection of fruit leading to Sphaeropsis rot.     

真桑钝绥螨捕食朱砂叶螨的实验种群生命表及捕食作用

为评价真桑钝绥螨Amblyseius makuwa Ehara防治害螨的可能性,本试验在(25±1)℃、RH 80%±5%、光周期16L:8D的条件下,组建了真桑钝绥螨以朱砂叶螨Tetranychus cinnabarinus Boisduv为食的实验种群生命表,研究了真桑钝绥螨雌成螨对朱砂叶螨卵、若螨和雌成螨的捕食作用。结果表明,真桑钝绥螨以朱砂叶螨为食,未成熟期发育历期分别为卵期1.90 d,幼螨期0.62 d,前若螨期0.82 d,后若螨期1.26 d。试验条件下真桑钝绥螨净增殖率为11.80,内禀增长率为0.175,世代平均周期为14.12 d,周限增长率为1.191,种群倍增时间为3.96 d,雌成螨日均产卵量为1.22粒,平均总产卵量为22.12粒。真桑钝绥螨对朱砂叶螨3个螨态的捕食功能反应均属于HollingⅡ型圆盘方程,拟合圆盘方程显示真桑钝绥螨对朱砂叶螨卵的捕食数量最大,其次为若螨和雌成螨,a/Th值分别为12.5162、5.8730和4.4009。综上研究结果,真桑钝绥螨具备优良天敌的基本特性,是朱砂叶螨的潜在天敌之一。