Population studies of the citrus psylla,Trioza erytreae: Factors influencing population size

An attempt was made to correlate population fluctuations of an isolated population of the citrus psylla,Trioza erytreae (Del Guercio) (Hemiptera: Triozidae), with both the availability of young developing leaves and the saturation deficit index. Citrus psylla population dynamics seems to be governed by more than these two factors. There were significant positive correlations among egg, nymph and adult numbers. Increases in the minimum temperature and minimum relative humidity were followed by increases in the numbers of adults, eggs and nymphs. Seedlings of four citrus cultivars which seem to be less attractive to adult psylla than the other cultivars were identified.     

木虱传播柑桔黄龙病及电镜检验报告

 本试验在福建省福州市及广东省侥平县两地进行。1978年以来,在福州市以蕉柑、福桔和新会甜橙病树为毒源树,以柑桔实生健苗为指示植物,进行木虱传试验。结果在329株指示苗中,发病40株,发病率12.2%,潜育期短的半年,长的5年。对照指示苗72株均未见发病。1982~1984年,在饶平县以蕉柑病树为毒源树,以椪柑实生健苗为指示植物,共试验70株,发病33株,发病率47.1%,潜育期短的2个月,长的8个月。对照指示苗9株未见发病。木虱传染病苗的病状与毒源树的病状相同,均表现黄梢和叶片斑驳。获"毒"木虱的唾液腺和脂肪体的超薄切片样本在电镜下均观察到原核细胞微生物(称为类立次克体或类细菌)。唾液腺内的病原体分布在外皮层细胞,内皮层细胞和腺腔内。其菌体的形状大小和膜壁结构等特征均与毒源树及木虱传染病苗的筛管细胞内的相同,木虱获得和传递柑桔黄龙病病原的方式与蚜虫传播病毒中的持久性类型十分相似。     

柑桔木虱(Diaphorina Citri Kuw.)卵及若虫空间分布型的研究及其应用

经两年的田间调查资料,用8种检验分布型的方法进行检定,得出柑桔木虱卵和若虫的分布型均呈聚集分布。卵的聚集是由于木虱的习性引起的,若虫的聚集是由于环境的作用引起的。进行资料代换时可用下列公式: 1.y=log(x+1) 2.x=1n(x+1)本文还提出估计田间种群数量时的最适抽样数。     

栗等鳃金龟在广西来宾蔗区的发生为害与防治建议

2010-2014年对广西来宾市兴宾区平阳镇蔗区进行栗等鳃金龟发生为害情况调查。结果表明,栗等鳃金龟在平阳镇蔗区发生为害比较严重,2010/2011榨季田间虫口密度高达21 000.1头/667m2,受害株率高达82.0%,2013/2014榨季甘蔗受害株率为30.4%,栗等鳃金龟为害造成的产量损失率为32.0%,糖分损失率为23.3%。建议采用综合防治方法进行防治。     

应用Nested PCR技术检测柑桔木虱及其寄主九里香的柑桔黄龙病带菌率

应用PCR及Nested PCR技术检测柑桔木虱及其寄主九里香的结果表明:PCR只可检测最低2头带菌木虱,Nested PCR可检测到单个带菌木虱。100头带菌木虱中,单虫检出率为96％。检测田间重、中等、轻病的柑桔园内的木虱,其带菌率依次为87％、53％和21％。在病芦柑上饲菌不同天数的木虱均能检测出带菌,其饲菌时间最短为1d。城市九里香叶片及在其叶上取食的木虱单虫,均能用Nested PCR检测出病原。饲菌木虱接种九里香及芦柑健苗,在植株尚未表现症状时,常规PCR难检测出病原,但用Nested PCR则能检测到病原,说明九里香不仅是木虱的寄主,而且是黄龙病病原的隐症寄主。     

柑橘黄龙病的传播介体-柑橘木虱在广东果园的发生调查

柑橘木虱是重要害虫也是柑橘黄龙病的传播介体,因此调查木虱发生动态及其携带黄龙病菌的情况对指导黄龙病的防控有重要意义。本研究调查了广东多个果园的黄龙病发病情况,观察了柑橘木虱的生物学特性,统计了柑橘木虱在不同月份的发生数量,检测了木虱携带黄龙病菌情况。结果发现:失管果园中,黄龙病发病严重且木虱数量大,已成为散播病害的重要源头,而与失管果园保持一定距离且加强木虱防控可减轻黄龙病危害;还发现:广东地区6月份柑橘木虱种群已有一定数量,7、8月,其种群数量再次攀升,到了9、10月份,种群数量保持在高位。11、12月间,种群数量快速下降。最后根据本研究的调查结果,提出了一些加强黄龙病防控的措施。     

柑桔黄龙病综合防治研究

实施以采用无病种苗和田间防疫为中心的柑桔黄龙病综合防治技术,在新区两项措施并举,现树龄已９￣１４年生,仍然健康高产,每ｈｍ＾２产量达３２６００ｋｇ,田间保持既无黄龙病株,亦无柑桔木虱,对病区仅施行“田间防疫”,也能压低田间病株率和控制田间传染,维持果园效益。     

灭幼脲类杀虫剂—XRD—473对桔潜叶蛾,桔木虱及其天敌的毒杀试验

ＸＲＰ－４７３是灭幼脉类杀虫剂，试验结果表明，对柑桔潜叶蛾和柑桔木虱有较好的防治效果，对一些柑桔害虫的天敌较安全。用７０ｐｐｍＸＲＤ－４７３防治潜叶蛾１－２龄幼虫，校正死亡率为７８．７％和９３．６％，作为对比的杀灭菊酯为２２．％。用５０ｐｐｍ防治柑木虱初龄若虫校正死亡率９１．１５％，但对上述两种害虫的老龄幼、若虫效果稍差。用５０ｐｐｍ对脯食性天敌草蛉、蜘蛛、瓢虫捕螨田间施药试验，１０天后几种天敌数     

中国梨喀木虱对六种非寄主越冬植物的适应性

为明确中国梨喀木虱Cacopsylla chinensis越冬代（也称冬型梨木虱）在非寄主越冬植物（苹果树、桃树、樱桃树、李树、杏树、山楂树）上的适应性,于实验室内测定其在选择性条件下对不同植物组合的趋向偏好及产卵特点,并测定非选择性条件下其在不同植物上的存活、产卵以及寄主转换后的死亡情况。结果显示,在选择性条件下,当有寄主植物梨树枝条存在时,冬型梨木虱对其的趋向占比为 24.29%,而对苹果树、桃树、李树、杏树、樱桃树和山楂树枝条的趋向占比分别为 25.76%、20.81%、13.26%、8.25%、4.01%和3.62%,在梨树和苹果树枝条上的产卵量为111.00粒和7.67粒,未在其他果树枝条上产卵;当无寄主植物梨树枝条存在时,冬型梨木虱对苹果树枝条的趋向占比最高,为 35.45%,明显高于对樱桃树、杏树、桃树、山楂树和李树枝条的趋向占比,分别为 15.96%、13.19%、13.05%、12.41%和9.95%,且在苹果树、樱桃树、李树、桃树、杏树和山楂树枝条上的产卵量分别为14.25、9.75、7.25、4.75、2.75和1.00粒,总产卵量下降。在非选择性条件下,梨树枝条上冬型梨木虱的致死中时为17.11 d,在其他非寄主果树枝条上的致死中时集中在7.00~9.00 d;其在梨树枝条上的14 d累计产卵量最高,为136.67粒,而在苹果树、樱桃树、桃树、杏树、山楂树和李树枝条上的14 d累计产卵量大幅减少,分别为41.00、11.30、5.33、1.00、1.00和0.67粒,在梨树枝条上卵的孵化率为74.26%,在苹果树枝条上卵的孵化率为24.80%,在其他果树枝条上卵极少孵化。冬型梨木虱从非寄主苹果树转到寄主梨树时对其存活影响较小,第8 天累计死亡率为13.33%,相反,从寄主梨树转到非寄主苹果树上后对其存活影响明显,第8天累计死亡率达到了81.67%。表明所测试的非寄主植物均不能满足冬型梨木虱存活和子代发育所需营养,仅可作为临时替代寄主或越冬过渡寄主,非寄主植物苹果树可作为致死性诱集植物用于冬型梨木虱的防治。     

Overwintering of the Japanese bayberry whitefly,parabemisia myricae,in Israel

The Japanese bayberry whitefly,Parabemisia myricae (Kuwana), was discovered in Israel on citrus and avocado trees in 1978. In order to clarify its mode of overwintering, observations and counts were carried out during the winters of 1979/80, 1982/83 and 1983/84, with the following findings. Larvae and adults were detected on citrus and avocado trees throughout the winter; only females were found. The oviposition rate ofP. myricae in winter was low, and rose steeply in spring. The density of larvae on the lower side of leaves was higher than on the upper side. Substantial numbers of larvae survived the winter on avocado trees. Emergence of adults became intensified at the end of February, reached a peak in early March, and ceased at the end of March or beginning of April.     

Frequency and seasonal distribution of pear psylla infected with the pear decline phytoplasma in california pear orchards

ABSTRACT Pear decline (PD) is an important disease of Pyrus communis fruiting cultivars in Europe, Asia, and the Americas. PD is caused by a phloem-limited phytoplasma that, in California, is transmitted from diseased to healthy trees by pear psylla, Cacopsylla pyricola. The percentage of phytoplasma-infected pear psylla has never been assessed in the United States in field-collected insects. Pear psylla were collected monthly from PD-infected trees from three orchards in northern California. Individual psylla were tested for the presence of PD phytoplasma, using both a quantitative DNA hybridization and PD phytoplasma-specific polymerase chain reaction (PCR) assays. The percentage of infected psylla ranged from 0 to 45% depending on the orchard, the month and year collected, and the method of detection. The PD phytoplasma was detected in both the winterform and summerform pear psylla. Significantly more infected psylla were detected with PCR than with DNA hybridization analysis in two of the three orchards. The number of PD phytoplasma per pear psylla was estimated to range from 1 x 10(6) to 8.2 x 10(7). The percentage of PD-infected pear psylla found in the three northern California pear orchards suggests that both winterform and summerform pear psylla could be important in the transmission of PD.     

A combined indexing and budwood propagation method for citrus

Several budwood-transmitted citrus diseases, including citrus tristeza virus, citrus psorosis, citrus impietratura and a range of citrus viroids, were tested both visually and biochemically on a combined indicator (CInd) plant consisting of an Alemow (Citrus macrophylla) rootstock grafted with Etrog citron (C.medica) and Sour orange (C.aurantium) or Sweet orange (C.sinensis) buds. Indexing on CInd plants is economical for limited testing space; an additional advantage is that, by collecting budwood directly from the CInd plants, the risk of diagnostic failure due to uneven pathogen distribution in the budwood source tree is considerably reduced.     

柑橘大实蝇成虫最佳诱捕时间和诱捕地点

为有效诱捕柑橘大实蝇Bactrocera minax成虫,首先调查5个不同橘园中柑橘大实蝇成虫发生量和落果数量,计算落果率,对诱捕时间和诱捕成虫百分比进行Logistic方程拟合分析,然后调查全田、橘园、交界带、杂树林、橘园中心5个生境下柑橘大实蝇觅食高峰期成虫发生量,并对各生境下柑橘大实蝇成虫发生量和各橘园中落果率进行相关性分析及回归分析。结果表明,觅食高峰期柑橘大实蝇的最佳诱捕时间为5月31日—6月27日。除杂树林外,觅食高峰期全田、橘园、交界带和橘园中心柑橘大实蝇成虫发生量和落果率之间均呈显著正相关。通过比较5个生境拟合回归方程的判定系数和均方根误差确定在交界带生境中柑橘大实蝇成虫发生量与落果率的二次三项式模型拟合效果最好,因此,交界带为柑橘大实蝇成虫的最佳诱捕地点。     

Impact of some alternative methods to chemical control in controlling aphids (Hemiptera: Sternorrhyncha) and their side effects on natural enemies on young Moroccan citrus groves

Aphid control in Moroccan citrus orchards is based mainly on carbamate and neonicotinoid sprays, especially methomyl and imidacloprid. The extensive use of these insecticides may have side effects on natural enemies and environment quality and raises human health concerns. This research aimed to assess the control of aphids with insecticidal soap, kaolin and augmentative biological control using the indigenous predator Adalia decempunctata L. (Coleoptera: Coccinellidae). The insecticides were applied and the predators were released in April 2009 and 2010. Under field experimentation, the methomyl and imidacloprid foliar pulverization were very effective against aphids. In contrast, the insecticidal soap and kaolin application were less efficient while A. decempunctata adults were effective only in the first week after release. The side effects on beneficial insects were also assessed and discussed. The possibility of employing A. decempunctata in an integrated pest management package in citrus groves is discussed in relation to effectiveness and side effects on beneficial arthropods.     

Natural enemies of the pear psylla<Emphasis Type="Italic">Cacopsylla pyri</Emphasis> in treated<Emphasis Type="Italic">vs</Emphasis> untreated pear orchards in Antalya,Turkey

Populations of pear psylla,Cacopsylla pyri (L.) (Rhynchota: Psyllidae), and its natural enemies were sampled on pears in Antalya province during the years 2000–2002. Thirty-two species of predators and three species of parasitoids were detected to be associated withC. pyri in Antalya province. The heteropterans (especially anthocorid species) were the most abundant predator group. Among the anthocorids,Anthocoris nemoralis (Fabricius) (Heteroptera: Anthocoridae), whose population was closely related to the dynamics of the pear psylla population, was generally the principal antagonist ofC. pyri. Other species recorded during the study were the miridDeraeocoris spp., the chrysopidChrysoperla carnea L., and many coccinellid species. Although these predators are polyphagous, as are theOrius species, their populations were related to the psylla fluctuations. Among the parasitoid complex belonging to the order Hymenoptera, the encyrtidTrechnites psyllae (Ruschka) was the only primary parasitoid. Two hyperparasites,viz., Syrphophagus mamitus (Walker) andPachyneuron aphidis (Bouché) (Encyrtidae and Pteromalidae, respectively), were detected in the surveys. Also, this study revealed new information concerning the pear psylla parasitoid complex in Turkey. WhileT. psyllae andS. mamitus are new records to Turkish parasitoid fauna,C. pyri is a new host record forP. aphidis. The population development and abundance of pear psylla and its natural enemies, as well as the parasitization rates in treated and untreated pear orchards, are presented here. http://www.phytoparasitica.org posting May 6, 2004.     

超高效液相色谱-三重四极杆串联质谱法测定柑橘中4种苯甲酰脲类农药残留

建立了柑橘中虱螨脲、灭幼脲、氟啶脲和除虫脲4种苯甲酰脲类农药同时检测的超高效液相色谱-三重四级杆串联质谱(UPLC-MS/MS)分析方法。样品采用QuEChERS前处理技术,超高效液相色谱-串联质谱电喷雾负离子模式检测测定。结果表明:在0.01~0.2μg/mL范围内,4种供试农药的质量浓度与其相应的峰面积间呈良好的线性关系,相关系数(r)均大于0.994。在0.01、0.05和0.1 mg/kg 3个添加水平下,4种农药的平均回收率为92%~105%,相对标准偏差(RSD)为0.4%~3.3%(n=5)。4种农药在柑橘中的定量限(LOQ)均为0.01 mg/kg。该方法准确、灵敏、简单,适用于同时测定柑橘中4种苯甲酰脲类农药的残留量。     

Antifeedant and sublethal effects of imidacloprid on Asian citrus psyllid,Diaphorina citri

BACKGROUND: Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits the causal bacteria of the devastating citrus disease huanglongbing (HLB). Because of the variation in spatial and temporal uptake and systemic distribution of imidacloprid applied to citrus trees and its degradation over time in citrus trees, ACP adults and nymphs are exposed to concentrations that may not cause immediate mortality but rather sublethal effects. The objective of this laboratory study was to determine the effects of sublethal concentrations of imidacloprid on ACP life stages. RESULTS: Feeding by ACP adults and nymphs on plants treated daily with a sublethal concentration (0.1 µg mL^?1) of imidacloprid significantly decreased adult longevity (8 days), fecundity (33%) and fertility (6%), as well as nymph survival (12%) and developmental rate compared with untreated controls. The magnitude of these negative effects was directly related to exposure duration and concentration. Furthermore, ACP adults that fed on citrus leaves treated systemically with lethal and sublethal concentrations of imidacloprid excreted significantly less honeydew (7–94%) compared with controls in a concentration‐dependent manner suggesting antifeedant activity of imidacloprid. CONCLUSIONS: Sublethal concentrations of imidacloprid negatively affect development, reproduction, survival and longevity of ACP, which likely contributes to population reductions over time. Also, reduced feeding by ACP adults on plants treated with sublethal concentrations of imidacloprid may potentially decrease the capacity of ACP to successfully acquire and transmit the HLB causal pathogen. Copyright © 2009 Society of Chemical Industry     

Introduced and native parasitoids of Phyllocnistis citrella Stainton in Greece: short term post-release evaluation

The Citrus Leafminer (CLM) Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is considered an important pest of citrus, damaging mainly nursery plants. In Greece it was first recorded on the island of Rhodes in 1995 and rapidly spread to all citrus growing areas of the country. Due to its wide expansion and damage, efforts were initiated to control this pest with biological control agents. For this purpose, a number of exotic parasitoids, such as Citrostichus phyllocnistoides (Narayanan), Quadrastichus sp. Girault and Semielacher petiolata (Girault) (Hymenoptera: Eulophidae), were introduced, reared in insectaries and released in several regions of Greece. The species composition and the seasonal abundance of the native parasitoids, as well as the recovery of the released parasitoids, were investigated in weekly samplings during 1998 and 1999 in a citrus orchard in Argolis district. Results showed that among the released parasitoids, only C. phyllocnistoides was recovered. Among the native parasitoids, Neochrysocharis formosa (Westwood), Pnigalio pectinicornis (L.) and Cirrospilus sp. Westwood (Hymenoptera: Eulophidae) were identified. The most abundant parasitoid species was the exotic C. phyllocnistoides. The highest percent of parasitism in 1999 increased approximately by 46% compared with that of the previous year. The percent of parasitism increased to its maximum level during November, at the end of the sampling period in both years, when the population density of C. phyllocnistoides was high.     

LncRNA在柑橘木虱与黄龙病病原菌互作中的差异表达分析及验证

为明确柑橘黄龙病的唯一自然传播媒介——柑橘木虱Diaphorina citri的长链非编码RNA(long non-coding RNA,lncRNA)是否参与调控黄龙病病原菌Candidatus Liberibacter asiaticus(CLas)的侵染及复制,采用生物信息学预测及PCR扩增方法进行lncRNA的预测、特征分析、验证及差异表达分析。结果显示,柑橘木虱的13个转录组RNA-Seq数据中共有10 192个lncRNA基因,对应15 747条lncRNA转录本;与蛋白质编码基因相比,柑橘木虱lncRNA具有更少的外显子数量和更短的转录本长度;随机选取的10条lncRNA基因中,有7条lncRNA基因在无菌柑橘木虱广州品系或赣州品系中有表达,其中1条lncRNA基因TCONS_00034665在无菌广州品系和无菌赣州品系中存在差异表达;带菌和无菌柑橘木虱成虫中预测获得2个差异表达的lncRNA基因TCONS_00096118和TCONS_00234564,实时荧光定量PCR验证发现TCONS_00234564与预测结果一致,在带菌柑橘木虱成虫中高表达。表明lncRNA参与了黄龙病病原菌与寄主柑橘木虱的互作。