Toxoptera Aurantii Research Articles

Spatial Distribution and Sampling Plans With Fixed Level of Precision for Citrus Aphids (Hom., Aphididae) on Two Orange Species.

Aphis spiraecola Patch, Aphis gossypii Glover, and Toxoptera aurantii Boyer de Fonscolombe are three important aphid pests of citrus orchards. In this study, spatial distributions of the aphids on two orange species, Satsuma mandarin and Thomson navel, were evaluated using Taylor's power law and Iwao's patchiness. In addition, a fixed-precision sequential sampling plant was developed for each species on the host plant by Green's model at precision levels of 0.25 and 0.1. The results revealed that spatial distribution parameters and therefore the sampling plan were significantly different according to aphid and host plant species. Taylor's power law provides a better fit for the data than Iwao's patchiness regression. Except T. aurantii on Thomson navel orange, spatial distribution patterns of the aphids were aggregative on both citrus. T. aurantii had regular dispersion pattern on Thomson navel orange. Optimum sample size of the aphids varied from 30-2061 and 1-1622 shoots on Satsuma mandarin and Thomson navel orange based on aphid species and desired precision level. Calculated stop lines of the aphid species on Satsuma mandarin and Thomson navel orange ranged from 0.48 to 19 and 0.19 to 80.4 aphids per 24 shoots according to aphid species and desired precision level. The performance of the sampling plan was validated by resampling analysis using resampling for validation of sampling plans (RVSP) software. This sampling program is useful for IPM program of the aphids in citrus orchards.

天敌对“乌牛早”茶园4种害虫空间跟随关系密切程度的年度差异

PDF HTML阅读 XML下载 导出引用 引用提醒 天敌对“乌牛早”茶园4种害虫空间跟随关系密切程度的年度差异 DOI: 10.5846/stxb201706271157 作者: 作者单位: 安徽农业大学,安徽农业大学,安徽农业大学,安徽农业大学,安徽农业大学,安徽农业大学林学与园林学院,安徽农业大学,安徽农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（30871444）；安徽省自然科学基金项目（11040606M71） Degree of close spatial-following relationship between four insect pests and their natural enemies studied in a span of two years about “WuNiuZao” tea garden Author: Affiliation: Anhui agricultural university,Anhui agricultural university,Anhui agricultural university,Anhui agricultural university,Anhui agricultural university,,Anhui agricultural university, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了合理保护和利用天敌及科学地选取抽样方法，2015年和2016年合肥地区乌牛早茶园茶蚜、假眼小绿叶蝉、卵形短须螨和双斑长跗萤叶甲与其天敌之间的空间关系，并比较两年间同一种天敌与该害虫空间跟随关系密切程度差异的原因。运用地学统计学方法求得天敌和害虫各自的变程，用灰色关联度方法分析害虫与天敌变程之间的关联度，关联度值越大的天敌在空间上对害虫的跟随关系越密切。与害虫空间跟随关系密切的前三位天敌，2015年茶蚜的是茶色新圆蛛、锥腹肖蛸和粽管巢蛛，2016年是锥腹肖蛸、八斑球腹蛛和鳞纹肖蛸，两年只有锥腹肖蛸相同。2015年假眼小绿叶蝉的是茶色新圆蛛，八斑球腹蛛和粽管巢蛛，2016年的是八斑球腹蛛、茶色新圆蛛和鳞纹肖蛸，两年间前三位天敌中有八斑球腹蛛和茶色新圆蛛相同，但位次不同。2015年卵形短须螨空间跟随关系密切的前三位天敌是茶色新圆蛛、粽管巢蛛和鳞纹肖蛸，2016年的是鳞纹肖蛸、粽管巢蛛和八斑球腹蛛，两年间前三位天敌中有粽管巢蛛和鳞纹肖蛸相同，但位次不同。2015年双斑长跗萤叶甲的是八斑球腹蛛、粽管巢蛛和鳞纹肖蛸，2016年的是鳞纹肖蛸、粽管巢蛛和茶色新圆蛛，两年间前三位天敌中有鳞纹肖蛸和粽管巢蛛相同，但位次不同。初步分析表明年度间与害虫跟随关系天敌位次的变化原因是，害虫个体数与某种天敌个体数之比，比值越小，天敌与害虫跟随关系越密切，似乎是天敌食饵资源短缺所致。 Abstract:To protect and use of natural enemies and provide scientific sampling methods, in this study, the spatial relationships among the natural enemies of the insect pests Toxoptera aurantii Boyer, Empoasca vitis Gothe, Breuipalpus oboyats, and Monolepta hieroglyphica were investigated in the tea garden of "WuNiuZao" in the Hefei suburban district, China in 2015 and 2016. The reasons for differences in the relationship between the same natural enemies and the pest species in the two years were evaluated. The ranges of spatial dependence (RSDs) of natural enemies were calculated using a geostatistics method, and the spatial relationships among enemies and pests were analyzed using grey relational analysis. A greater relative degree indicates a closer following space about the relationship between natural enemies and pests. The relational grade analysis showed that the three main enemies Neoscona theisi, Tetragnatha maxillosa and Clubiona japonicola Boes. et Str had a close relationshipwith Toxoptera aurantii in spatial-following relationships in the "WuNiuZao" tea garden in 2015. Although the three main enemies Tetragnatha maxillosa, Theridion octomaculatum Boes.et Str., and Tetragnatha maxillosa remained the same during the two years, the sorting was different in 2016. The relational grade analysis showed that the three main enemies Neoscona theisi, Theridion octomaculatum Boes. et Str., and Clubiona japonicola Boes. et Str had close relationship with Empoasca vitis in spatial-following relationships in the "WuNiuZao" tea garden in 2015. The three main enemies included Theridion octomaculatum Boes. et Str, Neoscona theisi, and Tetragnatha syusmata in 2016. Theridion octomaculatum Boes. et Str. and Neoscona theisi remained the same during the two years, but the seating arrangement was different. The relational grade analysis showed that the three main enemies Neoscona theisi, Clubiona japonicola Boes. et Str, and Tetragnatha syusmata had consanguineous relations with Breuipalpus oboyats in spatial-following relationships in the "WuNiuZao" tea garden in 2015. The three main enemies included Tetragnatha squamata Karsch, Clubiona japonicola Boes. et Str, and Theridion octomaculatum Boes et Str. Clubiona japonicola Boes. et Str and Tetragnatha squamata Karsch remained the same during the two years, but the sorting was different. The relational grade analysis showed that the three main enemies, Theridion octomaculatum Boes. et Str, Clubiona japonicola Boes. et Str, and Tetragnatha syusmata had consanguineous relations with Monolepta hieroglyphica in spatial-following relationships in the tea garden in 2015. The three main enemies included Tetragnatha syusmata, Clubiona japonicola Boes. et Str, and Neoscona theisi in 2016. Tetragnatha squamata Karsch and Clubiona japonicola Boes. et Str remained the same during the two years, but the sorting was different. The main reason for the change of the natural enemies of the pests during the two years is the difference in the ratio of the number of individual pests to the number of individual natural enemies:smaller the ratio, closer is the following relationship between predators and pests, which seems to be caused by a shortage in natural enemy species resources. 参考文献 相似文献 引证文献

Erratum to: Insecticidal effect of Mentha pulegium L. and Mentha suaveolens Ehrh. hydrosols against a pest of citrus, Toxoptera aurantii (Aphididae)

Essential oils proved their efficiency as natural insecticides to fight many pests of stored products and crops whereas the hydrosols have not been evaluated yet. The objective of this work is to assess the insecticidal effect of hydrosols extracted from Mentha suaveolens Ehrh. and Mentha pulegium L. toward an insect pest of citrus, Toxoptera aurantii (Homoptera, Aphididae). The extraction of hydrosols was carried out by hydro-distillation using Clevenger apparatus and then the chemical composition was identified by gas chromatography coupled with mass spectrometry. The chemical composition of two hydrosols revealed the abundance of hydrophilic and oxygenated compounds as piperitenone oxide and carvacrol. Different concentrations of each hydrosol were separately diluted in distilled water and applied topically to aphids. The results of this investigation have shown a high insecticidal effect, and the M. suaveolens hydrosol is more effective against citrus pests than that of M. pulegium L. Consequently, these natural compounds can be used in the management of aphids on citrus.

An evaluation of the effect of botanical insecticide, palizin in comparison with chemical insecticide, imidacloprid on the black citrus aphid, Toxoptera aurantii Boyer de Fonscolombe and its natural enemy, Aphidius colemani Viereck

AbstractThe black citrus aphid,Toxoptera aurantiiBoyer de Fonscolombe (Hemiptera: Aphididae), an important pest of citrus species, feeds by sucking sap from plant leaves. It causes some leaf distortion and malformation of growing leaves and shoot tips. In this study, the effects of the botanical insecticide, palizin onT. aurantiiand its parasitoid,Aphidius colemaniViereck (Hymenoptera: Brachonidae) were compared with the chemical insecticide, imidacloprid. The compounds were evaluated at maximum recommended field concentrations: palizin 2,000 ppm, imidacloprid 500 ppm, water (as control) on adult aphids. Spraying was done with a 100-l engine Honda sprayer (GX120T1, 160T1, 200T) until run-off. The number of dead aphids was recorded 24, 48 and 72 hours after treatment. According to the results, statistically significant differences were found between treatments (p ≤ 0.05). Twenty-four hours after treatment, imidacloprid was more effective than palizin in reducing theT. aurantiipopulation. Palizin showed high efficiency (95% mortality) 72 hours after treatment. However, at that time, there was no statistically significant difference between the mean mortality percentages of imidacloprid and palizin. This shows that botanical insecticide, palizin can effectively controlT. aurantii. Also, palizin caused low mortality (10.86%) onA. colemaniwhile imidacloprid was more toxic (31.1% mortality). The results of the present study indicated that palizin can be used instead of chemical insecticide, imidacloprid in control programs ofT. aurantii.

HAMA TANAMAN BELIMBING DI WILAYAH KABUPATEN BLITAR JAWA TIMUR

Pests of star fruit in Blitar District, East Java. Pest attack causes the production of star fruit decreases. This study aim was to identify the pests of star fruit in Blitar District which could provide an information about pest species, damage symptoms and damage intensity. The research was conducted during August – September 2014 in Gogodeso, Karangsonoand Pojok Villages at Blitar District, East Java. Observations of the pests ware done by determining the four locations of plantation on each villages randomly. Three plants sample were choosen in each plantation location diagonally. Each plant was divided into four quadrant according to wind directions. One branch in the bottom was choosen in each quadrant. Nine species were recorded as pests of starfruit in Blitar district. Pest was identified on the leaf was Pteroma plagiophleps, on the branch was Zeuzera coffeae, on the flower were Toxoptera aurantii and Maconellicoccus hirsutus, whereas those on the fruit were Toxoptera aurantii, Maconellicoccus hirsutus, Thrips javanicus, Helopeltis bradyi, Cryptophlebia leucotreta, Bactrocera dorsalis, and Bactrocera carambolae. The population density of M. hirsutus was higher in Karangsono than in other villages. The highest damage intensity was caused by Bactrocera spp., C. leucotreta and H. bradyi (occured in Gogodeso), whereas the highest damage intensity of T. javanicus occurred in Pojok.

Biological Characteristics and Vegetative Propagation of a New Camellia Cultivar Maozi

Camellia flowers are highly prized for their beauty worldwide and are strongly symbolic in many cultures. A new interspecific hybrid cultivar, Camellia ‘Maozi’, generated by crossing Camellia pubipetala with C. japonica ‘Dahong Mudan’, exhibits strong hybrid vigor and has small flowers with a rare light tone of purple. In southwest China with a subtropical monsoon climate, young Camellia ‘Maozi’ trees flush shoots three times in spring, summer, and autumn, with an average annual growth of 12.9 cm. Adult trees flush once a year. Floral bud formation occurs in late April and early May. Camellia ‘Maozi’ flowers are sterile with no fruits and seeds produced. While an individual flower wilts 4–8 days after opening, the blossom can last 1–3 months. Frost damage can be found in young leaves when temperature drops to 4–7 °C. Under direct sunlight with temperatures of 37–39 °C lasting for more than 2 days, young leaves can turn yellow on their edges. Its primary diseases include sooty mold, shoot tip blight, and peony leaf tip blight. Its primary insect pests are tea green leafhopper (Jacobiasca formosana) and tea aphid (Toxoptera aurantii). Rooting of stem cuttings occurs directly from stems, mostly without callus development. Two hours of treatment with 500 mg·L−1 indole-3-butyric acid and rooting in a mix of latosolic red soil and vermiculite (2:1 v/v) resulted in high rooting rate and quality of aboveground growth. Grafting can be carried out from May to September, while survival rate and new shoot length are highest in July. The most compatible rootstock is C. oleifera, followed by C. polyodonta. The results of this study are of value for understanding the reproductive biology of Camellia ‘Maozi’ and further disseminating it as a new cultivar for camellia collection.

Aydın İl Merkezinde turunç Citrus aurantium L. (Rutaceae) ağaçlarında bulunan Coccoidea üst familyası ile Aphididae ve Aleyrodidae familyaları (Hemiptera)’ na bağlı türlerin saptanması, bulaşma oranlarının ve doğal düşmanlarının belirlenmesi

It was aimed to determine the pest species, their infection rate and their natural enemies on sour orange grown for landscape on Boulevards in three different district of the city center namely, Mugla Boulevard, Ataturk Boulevard and Bati Gazi Boulevard, and samplings were conducted in 2012 and 2013. Leaves and shoots were sampled on the trees and examined under stereo binocular microscope every 15 days in the laboratory to determine their infestation rate. Additionally, adult predators and parasitized pest individuals were also collected during sampling to determine the natural enemies. As a result, Coccus hesperidum (Linnaeus), Ceroplastes rusci (Linnaeus) and Aonidiella aurantii (Maskell) were determined in Coccoidea (Hemiptera) superfamily. Four aphid species, Aphis spiraecola (Patch), Aphis gossypii (Glover), Toxoptera aurantii (Boyer de Fonscolombe), and Myzus (Nectarosiphon) persicae (Sulzer) (Hemiptera: Aphididae) were also identified. Adalia fasciatopunctata (Mulsant), Oenopia (Synharmonia) conglobata (Linnaeus), Adalia bipunctata (Linnaeus), and Coccinella septempunctata (Linnaeus) (Coleoptera: Coccinellidae), and additionally Binodoxy angelicae and Lysiphlebus testaceipes (Hymenoptrera: Braconidae) were found as natural enemies on aphids. Aleurothirixus floccosus was sampled as whitefly, and Cales noacki Howard (Hymenoptera: Aphelinidae) was found to be natural enemy on A. floccosus. The parasitization was the highest in September in both study periods.

Diversity and density of tea pests in the tea gardens of Manipur

<p>Twenty one species of tea pests have been recorded for the first time from the tea gardens of Manipur which include twelve species of cutting and chewing pests, seven species of sucking pests, a stem borer and a leaf miner. Among them, red spider mite, (<em>Oligonychus coffeae</em>), leaf roller, (<em>Caloptilia theivora</em>), thrips (<em>Mycterothrips setiventris</em>) and aphid, (<em>Toxoptera aurantii</em>) were categorised as important pests and the rest as minor pests based on the observations carried out for one pruning cycle during 2010 to 2013. Field studies had shown that red spider mite (RSM) infested the tea plants all through the year with peak density of 16 mites per leaf per bush in April, whereas occurrence of thrips had been recorded with maximum abundance of 6 thrips per leaf per bush during October. On the other hand, tea aphids infested the plant from March to October with maximum of 200 individuals per 5 cm length of tea shoot in September. The stem borer, <em>Zeuzera coffeae </em>was noticed during March, April and September with an average density of 9.5 borers per 40 bushes. Among the foliage folders, leaf roller was predominant over flush worm and tea tortrix. Occurrence of leaf rolls was noticed from June to November with maximum incidence of 6 larvae per bush in October, but flushworms and tortrix were abundant even in April with the mean of 3 larvae per infested tea bush. Based on the above observation, a pest calendar was prepared for the tea pests of Manipur for planning pest control measures. Besides, 16 species of natural enemies attacking the tea pests are also reported in this article.</p>

Establishment ofMetarhizium anisopliae, an entomopathogen as endophyte for biological control in tea

Metarhizium anisopliae is among the ubiquitous members of the soil rhizosphere which also survives as an endophyte in a wide range of plants. The extent of colonization depends on the plant part evaluated and inoculation method used. Current research reveals that foliar spray favours leaf colonization, whereas soil drenching favours root colonization. Besides M. anisopliae, many other fungal isolates were recovered as endophyte which was found to be endosymbiont with each other. Infestation of aphid, Toxoptera aurantii; tea mosquito bug, Helopeltis theivora; termite, Odontotermes obesus; red spider mite, Oligonychus coffeae and carpenter worm, Prionoxystus robiniae was found less in the treated plot as compared to the untreated control. System season long endophytic colonization with the plants suggests a novel approach of biological control of these pests via foliar spray with M. anisopliae for aerial pests and soil drench for soil arthropods. The same entomopathogen was also further confirmed by light and electron microscopic techniques inside the host plant. Molecular study showed that the original culture and endophytic reisolated culture of M. anisopliae were 100% identical to each other.

Relating shading levels and distance from natural vegetation with hemipteran pests and predators occurrence on coffee

AbstractThe study was carried out to determine the effect of shading levels and/or distance from the natural alpine vegetation (NAV) on the occurrence of two insect functional groups: hemipteran herbivores and generalist predators in farmers' coffee fields in the Mt. Elgon region of Uganda. Three distance categories from the NAV, that is (i) 0–250 m; (ii) 250–1000 m and (iii) 1000–1500 m, were used to demarcate farms in the first stage of selection, and within each distance category, three levels of shading, that is (i) no shade, (ii) moderate shade and (iii) full shade, were used for final selection of coffee farms for the study. A total of 90 individually owned coffee fields were studied; 30 for each distance category, of which 10 represented each shading level. In two separate rounds, inventories of scale insects (Coccus spp.), antestia bugs (Antestiopsis spp.), root mealybugs (Planococcus spp.) and aphids (Toxoptera aurantii) on coffee plants were made for the hemipteran herbivores, whereas ants (Formicidae) and spiders (Araneae) were recorded for the predatory taxa. The results showed that the interaction between distance from the NAV and shading level consistently influenced the occurrence of the insects in both functional groups. For scale insects, root mealybugs and ants, it was closest to the NAV that shading‐level effects were most discernible and generally limiting. To the contrary, the occurrence of aphids and spiders increased with the increase in the level of shading for plants furthest from the NAV. These results indicate that if inclusion of shade trees is to be a strategy in ecological pest management, the level of shading should be determined basing on the insect taxa as well as other pertinent factors in the landscape.

茶互利素和蚜性信息素及其组合调控大草蛉行为的效应

The tea aphid,Toxoptera aurantii( Boyer),aggregates,pierces and sucks the sap of the tea shoots. The chemical control is not practical and restricted,since the tender tea shoots are commonly used for producing quality tea leaves. The green lacewing,Chrysopa septempunctata Wesmael,is one of the most important natural enemies of the tea aphid. However,the effectiveness of using this predator to suppress tea aphid populations is limited by their dispersal behavior and inefficiency of prey search. Here,we proposed a new strategy for enhancing the biological control against thetea aphids by using the tea shoot synomones and the aphid sex pheromones as potential lacewing attractant lures. The volatiles were collected from aphid-damaged tea shoots and intact tea shoots by the headspace sampling technique,and analyzed by gas chromatography coupled with mass spectrometry.( E)-2-pentenal,benzaldehyde and α-farnesene were identified as three dominant volatile components,followed by other 13 compounds from aphid-damaged tea shoots. EAG responses by the lacewing antennae were tested on the 16 synthetic individual compounds identified from aphid-damaged tea shoots,the two known aphid sex pheromone components( nepetalactone and nepetalactol),and a synthetic mixture containing α-farnesene,benzaldehyde and nepetalactol at ratio of 2∶2∶6,at 200 !g loading dosage for each tested compound or mixture. Nepetalactol,nepetalactone,α-farnesene,( E)-2-pentenal and benzaldehyde elicited higher EAG responses than did the other identified volatile components. However,the highest lacewing EAG response was observed to the synthetic mixture of α-farnesene,benzaldehyde and nepetalactol. This synthetic blend,aphid sex-pheromone,nepetalactone and nepetalactol,blends at seven different ratios( 10∶0,9∶1,7.5∶2.5,5∶5,2.5∶7.5,1∶9,0∶10),( Z)-3-hexen-1-ol,( E)-2-pentenal,( E)-2-hexenal,benzaldehyde and α- farnesene,each at 10 mg dosage,were tested in the field. Our field trapping results showed that the synthetic blend of α-farnesene,benzaldehyde and nepetalactol was the most attractive to C.septempunctata adults,followed by nepetalactol alone and the binary blend of nepetalactone and nepetalactol at 1∶ 9 ratio,which caught more lacewings than did the other ratios of the pheromone binary blends or other individual plant volatile compounds. During the field observations,we also found that the lacewing adults were not only attracted to lure-baited tea plants to directly prey on aphids,but also oviposited to raise their larva overwintering population in the habitat with plenty of overwintering aphid eggs. The deployment of lacewing attractant lures on tea plants may provide a unique,novel,and non-traditional control strategy against the economically important tea aphids.

Field evaluation of different chemical pesticides against aphid toxoptera aurantii on different tea (Camellia sinensis L.) cuttings under high shade nursery

Experiment was conducted at National Tea & High Value Crops Research Institute, Shinkiari, Mansehra-Pakistan during 2011-12 with the objectives to evaluate the efficacy of different chemical pesticides i.e. Tarzan (Cypermethrin 10EC), Piceal (Alphacypermethrin 10SC) and Buzer (Alphacypermethrin 10% W/V) were used to compare their effectiveness in relation to control the aphid infestation on growing shoots and their control at nursery stage. The mortality of aphid on tea cutting significantly affected under chemical pesticide Tarzan caused highest mortality 64%, 63%, 52%, 55%, 59%, 59%, 41% and 54% respectively, pesticide Piceal ranked second in relation to efficacy against aphid with insect mortality 36%, 40%, 40%, 28%, 37%, 36%, and 43% respectively. Whereas insecticide Buzer showed less efficacy among the other two insecticides on all tea cuttings application after 24 hours. Similar trend was observed in other treatments.

Sex pheromone of the tea aphid, Toxoptera aurantii (Boyer de Fonscolombe) (Hemiptera: Aphididae)

The tea aphid, Toxoptera aurantii, also called the “black citrus aphid”, is one of the most destructive insect pests in commercial tea plantations and gardens in southern China. In autumn, declining day length triggers production of winged T. aurantii sexuparae, which produce both winged males and wingless oviparae. Oviparous females then release sex pheromone that attracts potential mates. GC–MS analysis of volatile headspace extracts of T. aurantii oviparae revealed that they emit (4aS,7S,7aR)-nepetalactone (I) and (1R,4aS,7S,7aR)-nepetalactol (II) in a ratio of 4.3–4.9:1. Field-trapping experiments with synthetic I and II singly or as two-component blends of different doses and ratios showed significant attraction of T. aurantii males, as well as weak attraction of sexuparae. Identification of the T. aurantii sex pheromone provides a new opportunity for developing a pheromone-based monitoring and management strategy for the sexual phase of tea aphids and, possibly, the alate sexparous generation in late summer and fall.

A study on the comparative predatory efficiency and development ofMicraspis discolor(F.) andMenochilus sexmaculatus(F.) on tea aphidToxoptera aurantii(Boyer de Fons.)

The tea aphid Toxoptera aurantii Boyer (Sternorrhyncha: Aphididae) is a major pest of the tea plant (Camellia sinensis (L.)). Micraspis discolor (F.) and Menochilus sexmaculatus (F.) (Coleoptera: Coccinellidae) are the most common predators of these pests in tea plantations of North East India. A laboratory study was conducted to evaluate the suitability of the tea aphid Toxoptera aurantii, as prey for these two ladybird beetles. The life cycle of M. sexmaculatus was found to be shorter than that of M. discolor. Aphid consumption by M. sexmaculatus was significantly higher than that by M. discolor. Aphid consumption by larvae of M. discolor and M. sexmaculatus was noticed to be higher in later instars. Females of both ladybird species consumed a significantly greater number of aphids per day than males. As for biological parameters and the predatory potential of the two ladybird species, the study results proved that M. discolor and M. sexmaculatus are effective biocontrol agents of the tea aphid and can ...

Evaluation of the Resistance of Different Tea Cultivars to Tea Aphids by EPG Technique

In order to investigate the resistance of tea plant to tea aphid, the feeding behavior of tea aphids on six different tea cultivars was monitored by (EPG) technique. The result showed that the duration of E1, E2 as well as (E1+E2) which was feeding waveforms of Toxoptera aurantii (Boyer) in tea phloem was significantly different by variance analysis (P<0.05) and so did the duration of the probing of T. aurantii in all the tea tissues. And the six tea cultivars were classified into three groups with cluster analysis, based on the six major parameters which were durations of np, C, E1, E2, F, and G waveforms, then the six major parameters of these three groups were detected by variance analysis, and the rank of six different tea cultivars' resistance to T. aurantii from strong to weak was Zhongcha 108, Sucha 1, Anjibaicha, Longjing 43, Xicha 5, and Sucha 120. As this result was in accord with the investigation into the tea field, we concluded that EPG technique was one of the most important means to examine tea plant resistance to T. aurantii and the durations of waveform E1, E2 and (E1+E2) were important parameters for evaluating resistance of tea plants to tea aphids.

Attraction of the tea aphid, Toxoptera aurantii, to combinations of volatiles and colors related to tea plants

AbstractThe tea aphid, Toxoptera aurantii Boyer (Hemiptera: Aphididae), is a major pest of the tea plant, Camellia sinensis (L.) O. Kuntze (Theaceae). The attraction of the aphids to different colors and volatile compounds from tea shoots was investigated. Fourteen compounds were identified using gas chromatography‐mass spectrometry from headspace samples of intact tea shoot volatiles (ITSV). Electrophysiological and behavioral responses of winged tea aphids to ITSV as well as to the full blend of 14 synthetic compounds, to a partial mixture of green leaf volatiles (GLV) included in the 14 compounds, and to individual synthetic compounds were studied by using electroantennography (EAG) and a Y‐tube olfactometer. The various tea volatiles and blends were strongly active, with ITSV being the strongest. In the greenhouse and in tea plantations, sticky boards of six different colors strongly attracted tea aphids in flight, with ‘rape‐flower yellow’ and ‘Chinese olive‐yellow‐green’ being the most attractive. Furthermore, these two boards in combination with ITSV attracted winged tea aphids more strongly than their corresponding colored sticky boards alone. In the greenhouse, plastic models of tea seedlings baited with (Z)‐3‐hexen‐1‐ol or the GLV mixture significantly attracted winged tea aphids in flight. This study demonstrates that green leaf volatiles from tea shoots are attractive to the tea aphid. The combination of these volatiles with the color light yellow or green, and the shape of tender tea shoots result in orientation flight and landing of winged tea aphids on host tea shoots.

Determination of the bacterial flora as a microbial control agent of Toxoptera aurantii (Homoptera: Aphididae)

Toxoptera aurantii (Homoptera: Aphididae) is one of the most important pests of many agricultural plants such as camellia, cocoa and coffee worldwide. The culturable bacterial flora of the pest was determined to find new microbes that can be used as biocontrol agent against T. aurantii. A total of six bacteria were isolated and identified by a variety of morphological, physiological, biochemical and molecular tests. In addition, an approximately 1,150 bp fragment of the 16S rRNA gene region was sequenced to verify isolate identification. According to the identification studies, the isolates were identified as Bacillus tequilensis Cb1, Chryseobacterium stagni Cb2, Pseudomonas flourescens Cb3, Rahnella aquatilis Cb4, Staphylococcus sp. Cb5 and Cb6. Pathogenicity of the bacterial isolates were carried out against the last instar nymphs of T. aurantii. The highest activity was obtained from Pseudomonas flourescens Cb3 with 50% mortality within 10 days after application (p<0.05). Mortalities of other treatments ranged from 6.6 to 20%. The results presented here show that Pseudomonas flourescens Cb3 appears to be a significant candidate as a possible biocontrol agent against T. aurantii and should be beneficial in the future biocontrol programs of the pest.

合肥秋冬季茶园天敌对假眼小绿叶蝉和茶蚜的空间跟随关系

为了合理保护和利用天敌及科学地选取抽样方法,开展了合肥地区秋冬季4个品种茶园假眼小绿叶蝉<em>Empoasca vitis </em>Gothe和茶蚜<em>Toxoptera aurantii </em>Boyer与其天敌之间空间关系研究,运用地学统计学方法求得天敌和害虫各自的变程,用灰色关联度分析方法分析害虫与天敌变程的关联度,关联度值越大的天敌在空间上对害虫的跟随关系越密切。分析了2010年9月28日至11月25日期间假眼小绿叶蝉和茶蚜数量最少的舒茶早茶园和二种害虫数量最多的平阳特早茶园天敌对害虫空间上的跟随关系,结果表明,二种茶园的假眼小绿叶蝉和茶蚜及其4种主要天敌均为聚集分布,舒茶早茶园与假眼小绿叶蝉空间上跟随关系密切的前二位天敌是斜纹猫蛛<em>Oxyopes sertatus</em> L.Koch(0.8594)和草间小黑蛛<em>Erigonidium graminicolum</em> Sundevall(0.8397),与茶蚜空间上跟随关系密切的前二位天敌是草间小黑蛛(0.7448)和斜纹猫蛛(0.7433);平阳特早茶园与假眼小绿叶蝉空间上跟随关系密切的前二位天敌是八斑球腹蛛<em>Theridion ocomaculatum</em> Bose.et Str(0.8207)和斜纹猫蛛(0.8104),与茶蚜空间上跟随关系密切的前二位天敌是八斑球腹蛛(0.8324)和斜纹猫蛛(0.7730)。其中,11月25日4种茶园假眼小绿叶蝉和茶蚜数量均较多。分析了该日另外二个茶树品种福云六号和龙井长叶茶园假眼小绿叶蝉和茶蚜与其天敌的空间关系,结果表明,二种茶园假眼小绿叶蝉和茶蚜及其天敌均为聚集分布,福云六号茶园与假眼小绿叶蝉变程值(3.8182)最接近的天敌是斜纹猫蛛(4.7222),与茶蚜变程值(6.5854)最接近的天敌是斜纹猫蛛(4.7222);龙井长叶茶园与假眼小绿叶蝉变程值(1.0000)最接近的天敌是八斑球腹蛛(1.0000),与茶蚜变程值(4.5000)最接近的天敌是斜纹猫蛛(7.6316)。总之,秋冬季4个品种茶园斜纹猫蛛在空间上是假眼小绿叶蝉和茶蚜跟随关系最密切的天敌,其次是八斑球腹蛛和草间小黑蛛。;To protect and utilize reasonably nature enemies, and provide scientifically sampling methods, in the this study, spatial relationships of natural enemies with <em>Empoasca vitis </em>(Gothe) and <em>Toxoptera aurantii </em>(Boyer) from late September to late November in 2010, respectively, were investigated in the four kinds of tea gardens of different cultivars (i.e. Shu tea, Ping yang te zao tea, Fu yun-six tea and Long jing chang ye tea) in Hefei suburban district, China. The ranges of spatial dependence (RSDs) of natural enemies and <em>Empoasca vitis </em>(Gothe) as well as <em>Toxoptera aurantii </em>(Boyer) were, respectively, calculated by the method of geostatistics, and the spatial relationships among enemies and pests were analyzed using grey relational analysis. The results showed that <em>Empoasca vitis </em>(Gothe), <em>Toxoptera aurantii </em>(Boyer) and four kinds of natural enemies (i.e. <em>Misumenops tricuspidatus </em>Fabr., <em>Theridion ocomaculatum </em>Bose. et Str., <em>Oxyopes sertatus </em>L. Koch and <em>Erigonidium graminicolum </em>Sundevall), respectively, displayed aggregative distribution pattern in the four kinds of tea gardens. The relational grade analysis showed that the two main enemies of <em>Oxyopes sertatus </em>L. Koch and <em>Erigonidium graminicolum </em>Sundevall, respectively, have consanguineous relation with <em>Empoasca vitis </em>(Gothe) and <em>Toxoptera aurantii </em>(Boyer) in spatial following relationships in the Shu tea garden. Whereas <em>Theridion ocomaculatum </em>Bose. et Str. and <em>Oxyopes sertatus </em>L. Koch, respectively, have very tight connection with <em>Empoasca vitis </em>(Gothe) and <em>Toxoptera aurantii </em>(Boyer) in spatial following relationships in the Ping yang te zao tea garden. <br> Specially, in the all four kinds of tea gardens, the most amount of <em>Empoasca vitis </em>Gothe and <em>Toxoptera aurantii </em>Boyer appeared on November 25, 2010, and the two kinds of insect pests and the four kinds of natural enemies, respectively, displayed aggregative distribution pattern in the Fu yun-six and Long jing chang ye tea gardens. Whilst the results showed that the main enemy of <em>Empoasca vitis </em>Gothe was <em>Oxyopes sertatus </em>L. Koch in Fu yun-six tea field, and <em>Theridion ocomaculatum </em>Bose. et Str. in Long jing chang ye tea field. While the main enemy of <em>Toxoptera aurantii </em>Boyer was <em>Oxyopes sertatus </em>L. Koch in the two kinds of tea fields. Moreover, our findings indicated that the RSDs of <em>Oxyopes sertatus </em>L. Koch in the two kinds of tea fields were 4.7222 and 7.6316, respectively. In conclusion, the present results revealed that the most main enemy of <em>Empoasca vitis </em>Gothe and <em>Toxoptera aurantii </em>was <em>Oxyopes sertatus </em>L. Koch Boyer in spatial following relationships in the four kinds of tea gardens in autumn-winter season, and then was <em>Theridion ocomaculatum </em>Bose. et Str. and <em>Erigonidium graminicolum </em>Sundevall.

First Report of Alfalfa mosaic virus Infection in Viburnum tinus in Chile.

Viburnum tinus L., commonly known as laurustinus, is an ornamental shrub that is widely used as a garden plant and flower crop. V. tinus is popular because of its desirable characteristics such as evergreen foliage, tolerance to pruning, winter blooms, and its adaptation to cold temperate zones. It is also relatively easy to grow and is commonly used as a windbreak. Infection of this ornamental species by Alfalfa mosaic virus (AMV) has been associated with yellow mottling or variegated leaf coloring, including light green and white, and has been referred to as the "Viburnum Calico" (1,4). In April 2011, at the onset of winter in the Southern Hemisphere, intense yellow spotting and mottling was observed on V. tinus leaves in the San Joaquin Campus at Pontificia Universidad Catolica de Chile. Presence of Aphis spiraecola Patch was observed on the shrubs, however, in the area it is also common to find other aphid species such as Toxoptera aurantii (Boyer de Fonscolombe) and A. fabae Scopoli. Leaf tissue samples from 10 asymptomatic and 10 symptomatic plants were examined for the presence of AMV by tissue-blot immunoassay with a commercially available polyclonal antibody (Agdia Inc., Elkhart, IN) along with the Goat affinity purified anti-rabbit IgG conjugated (Whole Molecule) (Molecular Probes, Invitrogen Corp., Carlsbad, CA). First-strand cDNA synthesis and PCR were performed with specific primers CP-AMV1 and CP-AMV2 (3). AMV was detected in all symptomatic leaves and also in two of the asymptomatic tissue analyzed by tissue blot assay. Reverse transcription (RT)-PCR produced 753-bp amplicons in all samples that were positive to AMV by tissue printing. No amplification product was observed when water control or seronegative samples were used as templates in the RT-PCR assays. Two amplicons were directly sequenced in both directions to confirm the identification of AMV in the leaf samples. The sequences obtained were homologous and BLASTN analysis of the submitted sequence (GenBank Accession No. JN040542) showed 99% nucleotide sequence identity to an AMV isolate described from Nicotiana tabacum L. (GenBank Accession No. FJ527749). These results demonstrate the presence of AMV in V. tinus in Chile. This pathogen has also been described to be affecting V. tinus in France (1) and V. lucidum Mill. in Spain (2). In Chile, V. tinum is increasingly grown as an ornamental plant. Therefore, care should be taken to ensure that the propagative materials of V. tinum are devoid of AMV infection to prevent further spread of this virus.

First field records of the sexuales (males and oviparae) of Toxoptera aurantii (Hemiptera: Aphididae)

Toxoptera aurantii (Boyer de Fonscolombe) is an aphid pest of great agricultural importance, not only due to its polyphagy but mostly due to its ability to transmit various plant viruses e.g. Citrus tristeza virus on Citrus (Blackman &amp; Eastop, 2000). Blackman &amp; Eastop (2000) considered this aphid to be entirely anholocyclic, because no sexual morphs have ever been observed in the field.