73％炔螨特乳油防治柑桔红蜘蛛药效试验

柑桔红蜘蛛(Panonychus citri)除为害柑桔外,还可为害多种作物.该虫以卵或成螨在柑桔叶背或枝条芽缝中越冬.红蜘蛛种群繁殖力强、世代重叠严重,严重时对柑桔花蕾及果实均可造成为害,导致落花、落果,树势衰退,严重影响柑桔产量和品质.     

炔螨特30％可湿性粉刺防治柑橘全爪螨药效试验

炔螨特30％湿性粉剂对橘全爪螨具有良好的防治效果,该药剂速效性一般,持效性强。5月中旬到6月初橘全爪螨盛发期使用,实际农业生产中使用900倍液为宜。     

炔螨特30%可湿性粉剂防治柑橘全爪螨药效试验

炔螨特30%可湿性粉剂对橘全爪螨具有良好的防治效果,该药剂速效性一般,持效性强.5月中旬到6月初橘全爪螨盛发期使用,实际农业生产中使用900倍液为宜.     

73%炔螨特乳油防治柑橘红蜘蛛试验

为验证73%炔螨特乳油对柑橘红蜘蛛的防治效果和最佳施药剂量,用73%炔螨特乳油2 000倍液、2 400倍液、3 000倍液对柑橘红蜘蛛进行药剂试验,防治效果较好。该药剂可在生产上大面积示范推广应用。     

浙江柑橘全爪螨对炔螨特的敏感性变化

2004年比较了浙江省4个橘园柑橘全爪螨对炔螨特的敏感性差异,仅发现LC50相差1.1～1.4倍。同一地区的全爪螨田间种群在1998-2004年间对该杀螨剂的敏感性也基本保持不变。结果表明:浙江橘区的柑橘全爪螨对炔螨特仍未产生明显的抗性,仅部分用药较多、用药历史较长地区的敏感性有所下降。连续4年停用炔螨特后的橘园,其柑橘全爪螨对炔螨特的敏感性得到明显恢复。     

几种药剂对桔全爪螨防效试验

金霸螨等5种杀螨剂对桔全爪螨防效表明：贵州独山柑桔产区桔全爪螨对金霸螨(2500倍)和金霸螨加氧化乐果(3000倍 1000倍)较为敏感，药后l～14d田间防效均在90％以上。三氯杀螨醇可作为桔全爪螨防治中的轮换用药．     

几种杀螨剂对二斑叶螨和朱砂叶螨的毒力测定

作者选用三氯杀螨醇、克螨特和螨克2种杀螨剂对朱砂叶螨(儋州、岳阳和射阳种群)和二斑叶螨作了毒力测定,明确3种杀螨剂对二斑叶螨的LC₅₀明显高于对朱砂叶螨,差异显著,已不能用于二斑叶螨的防治。螨克也已不适用于岳阳地区朱砂叶螨的防治。三氯杀螨醇和克螨特对朱砂叶螨儋州、岳阳和射阳种群的LC₅₀分别为237.79和804.64ppm、129.07和830.98ppm、112.03和732.32ppm,尚可在一定范围内用于对上述种群的防治,但应加强监测,注意与其他杀螨剂轮用,以延缓其使用期限。     

14种杀螨剂防治枸杞锈螨的室内活性试验

枸杞锈螨（Aculops lycii Kuang）,又名枸杞刺皮锈螨、锈螨,属于瘿螨科（Eriophyidae）锈螨亚科（Phyllocoptinae）,是近年来严重影响枸杞生产的重要害虫之一。枸杞锈螨主要为害枸杞叶片,也为害青果和嫩茎,影响品质,     

几种杀螨剂对二斑叶螨的药效试验

本文试验了杀螨利果、西斗星、三氯杀螨醇、螨虫素、爱及咪、蚜螨灵、克螨特、尼索朗等８种药剂对二斑叶螨ＴｅｔｒａｎｙｃｈｕｓｕｒｔｉｃａｅＫｏｃｈ卵、幼若螨和成螨的杀虫效果。结果表明，上述８种药剂中，杀螨利果效果最好，供试的３种浓度１５００、２５００和４０００倍对各虫态螨均有较好的杀虫效果，死亡率可达１００％；三氯杀螨醇、西斗星、爱及咪次之；螨虫素、蚜螨灵杀幼若螨和成螨效果较好，但杀卵效果较差，分别仅为３０％和６０％左右，克螨特对各虫态的效果均较差，且作用较为缓慢；尼索朗杀成螨效果较差，不及５０％，杀幼若螨效果一般，稀释１０００倍液对幼若螨的死亡率为９０％左右，但它具有很强的杀卵作用，用１０００倍和２０００倍液处理二斑叶螨卵，其死亡率均为９９％以上，是一种较好的杀卵剂     

9种常用杀螨剂对巴氏新小绥螨和二斑叶螨的毒力及毒力选择性研究

为使化学防治和保护利用捕食螨的生物防治措施相协调, 实现以螨治螨, 采用叶片残毒法分别测定了甘肃省保护地常用的9种杀螨剂对巴氏新小绥螨和二斑叶螨的LC50, 计算出各药剂的益害生物毒性选择指数(TSR)。供试药剂的毒性选择指数大小依次为：毒死蜱＞螺螨酯＞哒螨灵＞炔螨特＞唑螨酯＞阿维菌素＞三唑锡＞甲氰菊酯＞噻螨酮。其中, 毒死蜱和螺螨酯的毒性选择指数分别为10.864 1和9.361 3, 对巴氏新小绥螨和二斑叶螨均有较高的正向选择性, 毒死蜱和螺螨酯可优先用于生产中害虫(螨)的防治, 同时最大限度地保护了捕食螨, 实现对害虫(螨)化学防治和生物防治的相互协调。     

气相色谱-串联质谱法测定柑橘中5种杀螨剂残留

建立了气相色谱-串联质谱法(GC-MS/MS)检测柑橘中5种杀螨剂残留分析方法。样品经乙腈提取、氯化钠盐析后,取有机相用Qu EChERS方法净化,利用GC-MS/MS在多反应监测(MRM)模式下进行测定,外标法定量。5种杀螨剂在0.005~0.5mg/L浓度范围内呈现良好的线性关系,相关系数r^2均>0.996,方法定量限为0.005 mg/kg。在0.005、0.01和0.1mg/kg 3种添加水平下,加标回收率为70.6%~111.3%,相对标准偏差(RSD)为1.07%~14.64%。本方法简便、重现性良好,可用于柑橘类水果样品中杀螨剂的日常检测。     

江西省吉安、抚州两地区柑橘黄龙病发生调查

2005年至2008年,对江西省吉安和抚州两地区共20个县、区柑橘黄龙病发生情况进行了实地调查和病样室内诊断,结果表明抚州地区目前尚无柑橘黄龙病发生,吉安地区的吉安、永新、新干、峡江、安福、吉水、水丰也无黄龙病发生,而吉安地区的遂川、万安、泰和3县则已发现了黄龙病。柑橘品种对黄龙病抗病性存在差异,椪柑最感病,而南丰蜜橘则抗病。     

怀集县柑橘溃疡病发生现状及其对柑橘产业的影响

通过对怀集县柑橘溃疡病发生面积、发生程度和空间分布调查,分析柑橘溃疡病对怀集县柑橘产业发展造成的影响,就柑橘溃疡病发生原因,提出相应地防控措施。     

Establishment ofHarmonia axyridis on Citrus and Some Data on Its Phenology in Greece

In September 1993, a colony ofHarmonia axyridis Pallas (Coleoptera:Coccinellidae) was imported from France into Greece. In 1994, insectary-reared adults were released in 11 citrus orchards in four citrus-growing areas of Greece. Between May 19 and June 8, 1994,H. axyridis was recovered from a total of seven localities in three of these areas. This species was established on orange, mandarin and sour orange trees heavily infested withToxoptera aurantii, Aphis spiraecola andA. gossypii; its absence from the remaining four localities may have been the result of low prey densities. Twenty-three days after the initial releases,H. axyridis larvae comprised 57.9% and 83.3%, respectively, of the aphidophagous coccinellid larval populations in two localities (on Chios Island). In samples taken at Leonidion 43 days after the introduction release, both adult and larval populations ofH. axyridis represented approximately one-third of aphidophagous coccinellid adults and larvae found, whereas the indigenousAdalia bipunctata comprised about one-half of the population. In cages placed outside the Athens laboratory,H. axyridis completed four overlapping generations annually; average longevities of 56.2, 66.8, 78.9 and 102.2 days, respectively, were recorded for the successive generations. Adults of the 3rd and 4th generations overwintered, giving rise to the following year’s 1st generation. Oviposition began in April and emergence of 1st generation adults occurred in mid-May. The egg-laying activity of the females throughout the warm period of the year indicates thatH. axyridis does not diapause in summer. From December until March, small aggregations (2-4 individuals) were observed within the cages at protected sites.     

Laboratory Evaluation of Citrus Cultivars Susceptibility and Influence of Fruit Size on Fortune Mandarin to Infection by Alternaria alternata pv. citri

Young leaves of 62 citrus cultivars were inoculated with conidia of three Spanish isolates of Alternaria alternata pv. citri, the causal agent of brown spot of citrus. Hybrids with Dancy mandarin, King mandarin or their derivates as a parent, grapefruit cultivars and the mandarin cultivars Guillermina, Emperor, Clemenpons and Esbal were highly susceptible to the pathogen. Satsuma cultivar Clausellina and orange cultivars, with the exception of Sanguinelli, were slightly susceptible. Lemon and lime cultivars were not susceptible, with the exception of Mexican lime (Citrus aurantifolia), which was slightly susceptible. Although this study shows a range of potential hosts for this pathogen, to date the only affected cultivars in Spain are Fortune and Nova mandarins, and Minneola tangelo. The susceptibility of Fortune fruits decreased as diameter increased, being susceptible through the whole season. This was confirmed with field observations in autumn where fruit infections have been detected when the diameter reaches 6–7 cm.     

稻水象甲发生规律与药剂试验方法的探讨

稻水象甲是国际检疫对象，已经是我国北方水稻产区最重要害虫之一，并且呈迅速蔓延之势。此虫主要借助交通工具作远距离传播。成虫危害叶片，幼虫危害根系。一年繁殖一代但有两个危害高峰。新农药田间药效试验如果针对防治成虫、幼虫或者兼治，应在相应的时间、采取不同的方法进行。     

Elimination of Citrus psorosis virus by somatic embryogenesis from stigma and style cultures

Somatic embryogenesis was used to eliminate Citrus psorosis virus (CPsV) from three citrus species (common mandarin, sweet orange and Dweet tangor), all of which regenerated somatic embryos with different embryogenic potential from stigma and style explants. CPsV was detected by double antibody sandwich‐indirect‐enzyme‐linked immunosorbent assay (DASI-ELISA) in explants and embryogenic callus, but was not detected in any of the plants obtained from somatic embryos, even 24 months after regeneration. Loss of juvenile characters (disappearance of thorns) was observed in the first year of growth and was retained in plants propagated by grafting from thornless stems. Somatic embryogenesis appears to be a very promising technique for the production of healthy citrus stocks.     

Effect of Essential Oils from Citrus Varieties on in vitro Growth and Sporulation of Phaeoramularia angolensis Causing Citrus Leaf and Fruit Spot Disease

Citrus leaf and fruit spot disease caused by Phaeoramularia angolensis is a serious production constraint in tropical Africa. In previous studies, essential oils extracted from fruit peels of two tolerant varieties exhibited a strong antifungal activity in vitro against P. angolensis as compared to oils from susceptible ones. In order to investigate if the susceptibility of citrus varieties is associated with the antifungal activity of their essential oils, some 22 varieties of different susceptibility levels (tolerant, susceptible and highly susceptible) and belonging to different botanical groups were studied. Oils extracted from fruit peels were evaluated for their activity against radial growth and sporulation using the poisoned food technique. The optimal doses for growth inhibition and conidial reduction were 2500 and 1000 ppm, respectively. At these doses, radial growth and sporulation exceeded the untreated control respectively for four and nine varieties suggesting that oils from these varieties promote fungal development. In general, oils from the tolerant group were most effective in reducing radial growth irrespective of dose. The highly susceptible group ranked first in reducing sporulation at dose 1000 ppm (45.93%) while at higher doses of about 2000–2500 ppm, oils from the tolerant varieties could reduce sporulation up to 100%. The marked dose effect in reducing sporulation suggests that there may be different compounds acting with changing dose. Botanically, oils from pummelo (Citrus maxima, tolerant group), were best in reducing radial growth (>87% inhibition) while those from grapefruits (C. paradisi, highly susceptible group) were most effective in reducing sporulation (>64% reduction).     

Effect of temperature on RNA silencing of a negative‐stranded RNA plant virus: Citrus psorosis virus

Citrus psorosis virus (CPsV), genus Ophiovirus, causes a bark scaling disease of citrus. CPsV virions are kinked filaments with three negative‐stranded RNA molecules (vRNA) and a 48 kDa coat protein. The effect of temperature on symptom expression, virus accumulation and RNA silencing was examined in sweet orange seedlings (Citrus sinensis) graft‐inoculated with three different CPsV isolates and grown in a glasshouse at 26/18°C or 32/26°C (day/night). Most plants kept in the cooler glasshouse showed a shock reaction in the first flush with shoot necrosis, and then moderate to intense chlorotic flecking and spotting in young leaves, whereas plants incubated at 32/26°C did not exhibit shoot necrosis, and young leaf symptoms were milder. Virus titre estimated by ELISA and by northern and dot blot hybridization paralleled symptom intensity, with significantly higher virus accumulation in plants incubated at 26/18°C. The amount of CPsV‐derived small RNAs (CPsV‐sRNAs) slightly increased at 32/26°C, with the ratio of CPsV‐sRNA/vRNA being higher at 32/26°C than at 26/18°C. These results suggest that (i) CPsV infection induces RNA silencing in citrus plants, (ii) symptom intensity is associated with virus accumulation, and (iii) temperature increase enhances the RNA silencing response of citrus plants and decreases virus accumulation.     

松毛虫CPV、B.t.林间防治第一代马尾松毛虫试验初报

用松毛虫CPV和B.t.进行喷雾防治马尾松毛虫试验，试验表阴：药后18d两种生物药剂的防治效果均在70%以上，B.t.达86．98％，CPV与B.t.的混合使用防效达85．04％。