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1
Murata, Yasumasa. "UVB Damage and Photoreactivation in the Two-spotted Spider Mite, Tetranychus urticae." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225647.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第20422号<br>農博第2207号<br>新制||農||1047(附属図書館)<br>学位論文||H29||N5043(農学部図書室)<br>京都大学大学院農学研究科地域環境科学専攻<br>(主査)教授 天野 洋, 教授 田中 千尋, 准教授 刑部 正博<br>学位規則第4条第1項該当
2
Jones, Graeme. "Potential control of two spotted spider mite, tetranycus urticae koch using #beta#-fraction." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299764.
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3
Duarte, Vanessa da Silveira. "Studies for implementation of Neozygites floridana as control agent of two-spotted spider mite in strawberry." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-26072013-100955/.
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Neozygites floridana is an important natural enemy of Tetranychus urticae in many crops, including strawberry. In this crop there has been some changes in the production system from open field to low tunnel. This new system presents benefits to strawberry production, moreover this system increases problems with spider mites and some fungal plant pathogens; consequently increasing the use of pesticides. In order to integrate N. floridana in the management of spider mites in strawberry there are still many important aspects to be revealed on the biology, epizootiology of the fungus and the effect of crop systems on its prevalence in the field. For this, three studies were performed, being the first one about the effect of strawberry production systems (low tunnel and open field) and pesticide application on population dynamics of two-spotted spider mite T. urticae, its natural enemies (N. floridana and predatory mites), and plant diseases, the experiment was performed in Inconfidentes-MG. The population of T. urticae attained the highest level in treatments with chemical control of pest, independently of the crop system, low tunnel or open field. The fungus N. floridana was observed late in both crop seasons, in treatments with and without inoculative releases, and has suggested that it might be a natural occurrence of the fungus. The highest prevalence of the fungus were observed in treatments with high densities of T. urticae. The predatory mites occurred naturally during the two crop seasons, and the most abundant species was Neoseiulus anonymus (Chant) (57.5%). The incidence of fungal plant diseases are greater in the open field than in low tunnel, however it seems that the crop system do not affect the new disease \"vermelhao\". The second study aimed to reveal the abiotic and biotic factors involved in the regulation of resting spores formation in the hosts T. urticae and T. evansi. The Brazilian isolate ESALQ1420 produced a large number of resting spores (51.5%) in T. urticae at a temperature 11 °C, photoperiod of 10L:14D, light intensity of 42-46 (?mol m-2s-1), on non-senescent plants. Small percentages of mites with resting spores (0-5 %) were found for the Norwegian isolate NCRI271/04 under the conditions tested, and very low percentages of resting spores (up to 1%) were observed in T. evansi infected by the Brazilian isolate ESALQ1421.The third study was therefore conducted phylogenetic analysis of isolates of N. floridana and develops efficient real-time PCR-based analysis for detection and quantification of N. floridana propagules from the soil. The phylogenic three showed that Neozygites is a fungal group far from other Entomophthoromycota and that N. floridana present high intra-specific variability. This data indicates that the isolates from different Tetranychus species may be in fact different Neozygites species, not described yet. We developed a real-time PCR probe for detection and quantification of N. floridana in the soil. This molecular probe was successful in quantifying N. floridana at relatively high DNA concentrations seeded into the soil.<br>Neozygites floridana é um importante inimigo natural de Tetranychus urticae em diversas culturas, incluindo morango. Nesta cultura tem havido uma mudança no sistema de produção, passando de cultivo em campo aberto para túnel baixo. Este novo sistema apresenta benefícios na produção de morango, no entanto pode aumentar problemas com ácaros fitófagos e algumas doenças fúngicas, consequentemente aumentando o uso de agrotóxicos. Para a integração de N. floridana no manejo de ácaros fitófagos em morango, existem ainda muitos aspectos importantes a serem conhecidos sobre a biologia, epizootiologia do fungo e efeito dos sistemas de cultivo sobre a sua prevalência em campo. Para isso três estudos foram realizados, sendo o primeiro estudo sobre o efeito de sistemas de produção de morango (túnel baixo e campo aberto) e da aplicação de agrotóxicos sobre a dinâmica populacional do acaro rajado T. urticae, seus inimigos naturais (N. floridana e ácaros predadores) e doenças de plantas, o experimento foi realizado em Inconfidentes-MG. A população de T. urticae atingiu altos níveis em tratamentos com controle químico de pragas, independente do sistema de cultivo, túnel baixo ou campo aberto. O fungo N. floridana foi observado no final de ambos os ciclos de cultivos, nos tratamentos com e sem liberações inoculativas, sugerindo que houve incidência natural do fungo. As maiores prevalências do fungo foram observadas em tratamentos com altas densidades de T. urticae. Os ácaros predadores ocorreram naturalmente durante os dois ciclos de cultivo, sendo Neoseiulus anonymus (Chant) a espécie mais abundante (57.51%). A incidência de doenças fúngicas foi maior em campo aberto do que em túnel baixo, no entanto parece que o sistema de cultivo não afetou a incidência da nova doença vermelhão. No segundo estudo objetivou-se conhecer os fatores abióticos e bióticos envolvidos na formação de esporos de resistência nos hospedeiros T. urticae e Tetranychus evansi. O isolado brasileiro ESALQ1420 produziu um grande número de esporos de resistência (51.5%) em T. urticae, a uma temperatura de 11 ° C, fotoperíodo de 10F:14E, intensidade de luz de 42-46 (?mol m-2s-1), em plantas senescentes. Pequenas percentagens de ácaros com esporos de resistência (0-5%) foram encontrados para o isolado Norueguês NCRI271/04 sob as condições testadas, e muito baixas percentagens de esporos de resistência (ate 1%) foram observados em T. evansi infectados pelo isolado brasileiro ESALQ1421. O terceiro estudo objetivou analisar filogeneticamente os isolados de Neozygites patogênicos a ácaros, e desenvolver ferramenta utilizando PCR em tempo real para a detecção e quantificação de propágulos de N. floridana a partir do solo. A arvore filogenética mostrou que Neozygites e um grupo de fungos distante dos demais Entomophthoromycota, e que estes fungos apresentaram alta variabilidade intraespecífica entre isolados de N. floridana. Estes resultados indicam que isolados provenientes de diferentes espécies hospedeiras do gênero Tetranychus podem ser de fato diferentes espécies de Neozygites não descritas ainda. Desenvolveu-se uma sonda molecular para detecção e quantificação de N. floridana no solo utilizando PCR em tempo real. Esta sonda foi eficiente na quantificação de N. floridana, em concentrações relativamente altas de DNA inoculado no solo.
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Kara, Fatma Ebru Ay Recep. "Clofentezine, fenpyroximate ve amitraz ile seleksiyon yapılmış tetranychus urticae koch populasyonlarının direnç, çoklu direnç, direnç kalıtımının ve bazı enzim düzeylerinin belirlenmesi /." Isparta : SDÜ Fen Bilimleri Enstitüsü, 2008. http://tez.sdu.edu.tr/Tezler/TF01123.pdf.
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5
Khan, Inamullah. "Aspects of the biology of the ladybird beetle Stethorus vagans (Blackburn) (Coleoptera: Coccinellidae) /." View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20031103.132342/index.html.
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Hales, Lavinia Anne. "Genetics of sex ratio and other life history traits in the two-spotted spider mite (Tetranychus urticae Koch) /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487850665559541.
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Rethwisch, Michael D., Bradley J. Griffin, Jessica L. Grudovich, Jessica Hawpe, Krystyl Bolin, Shirley Plemmons, Ben Hayden, Marlo Barron, Alvin Lau, and Mark Reay. "Evaluation of various miticidal products for two-spotted spider mite, alfalfa caterpillar, and beet armyworm control in alfalfa." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/205398.
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"A number of products with miticidal activity were applied both in the spring and summer of 2002 to alfalfa in the Blythe, CA, area to evaluate their efficacy for twospotted spider mite (Tetranychus urticae) control. These two application periods differed in regards to presence of western flower thrips (Frankliniella occidentalis), a predator of spider mites. Western flower thrips populations were high in the spring but essentially absent during the period following the summer application, providing contrasting data for effects of western flower thrips interactions with many miticides for spider mite control. Miticides tested included those currently utilized for mite control in alfalfa hay production as well as a number of new and/or potential products for alfalfa hay.
In the spring testing, most treatments had more spider mites than the untreated check at three days post treatment when western flower thrips were present and actively feeding on spider mites. Two fertilizer treatments that contained high amounts of sulfur also had more spider mites than the untreated check at three days post treatment, thought due to repellency of adult western flower thrips. Many of the treatments that had more spider mites than the check following the spring application are known to have thrips activity (Zephyr, Trilogy, Dimethoate, Lorsban, etc.). Fewer motile (adults and immatures, not eggs) spider mites than in the check were noted only from the Capture + Dimethoate 400, Capture, and the combination of the two Gowan numbered products (1528, 1549) at three days after treatment.
Products that provided excellent (90%+) control throughout the duration of the summer part of the experiment included two numbered compounds from Gowan (1528 and 1549), Capture + Dimethoate 400, Danitol, Zephyr + Trilogy, and a numbered compound from Valent USA (V-1283). The wide disparity in the two data sets indicate that western flower thrips presence/absence should be considered as part of the decision making process for spider mite control. "
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Yorulmaz, Sibel Ay Recep. "Tetranychus urticae (Acarina: teranychidae)'nin üç farklı insektisit-akarisit ile seleksiyonundan sonra çoklu direnç ve bazı enzim düzeylerinin incelenmesi /." Isparta : SDÜ Fen Bilimleri Enstitüsü, 2008. http://tez.sdu.edu.tr/Tezler/TF01124.pdf.
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Astudillo, Fernandez Aina. "Influence of the Allee effect and collective behaviour on population dynamics: the case of the two-spotted spider mite." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209875.
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The Allee effect corresponds to a positive relationship between population size and individual fitness. This positive relationship can cause thresholds, that is, critical population sizes below which the population becomes extinct. For species submitted to the Allee effect, the formation and cohesion of groups is therefore crucial to survival. Animals can achieve this collective behaviour through local interactions. Each individual interacts locally with conspecifics and, at the scale of the group, a unity of behaviour emerges: the animals move together, rest in the same place, or choose the same habitat patch to settle on. <p><p>We use a combination of mathematical modelling and experimental work to study certain mechanisms of collective behaviour. In particular we assess the extent to which different individual interactions can induce collective patterns and thereby influence the dynamics of dispersal and settlement of populations. First, we study the collective settlement induced by the arresting effect of a marker secreted by conspecifics. Then, two potential mechanisms for collective movement are examined: following the conspecifics and following a trail laid by conspecifics. Finally, we integrate explicit mechanisms of dispersal behaviour in a dynamic model involving a set of interconnected populations. This allows the study of the interplay between collective movements and Allee effects at the scale of the metapopulation.<p><p>Our work is inspired by the lifestyle of the two-spotted spider mite, Tetranychus urticae, a phytophagous pest of recognised agricultural importance. These subsocial mites live in aggregates on the leaf surface, protected by a collectively spun silk web. Experimental evidence suggests that its population dynamics are subject to the Allee effect. Moreover, these mites show a tendency to migrate collectively, which makes them an appropriate biological model.<br>Doctorat en Sciences<br>info:eu-repo/semantics/nonPublished
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Brenner, Robert J. "Influence of Neonicotinoid Seed Treatment on Two Co-Occuring Arthropod Pests, Two-Spotted Spider Mite (Tetranychus urticae) and Western Flower Thrips (Frankliniella occidentalis)." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/31549.
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Insecticidal neonicotinoid seed treatments in agriculture is a common insect pest management strategy. Seed treatments have systemic and residual toxicity, which are effective against target insect pests. However, effects on other arthropod pests is less straightforward. We evaluated the effects of a neonicotinoid seed treatment, thiamethoxam, on two soybean pests, herbivorous two-spotted spider mites (Tetranychus urticae Koch) and an omnivore and facultative predator of spider mite eggs, western flower thrips (Frankliniella occidentalis Pergande). We used greenhouse and laboratory experiments to evaluate thiamethoxam soybean seed treatments on spider mite densities and thrips omnivorous feeding behavior. Our results suggest seed treatment may encourage spider mite reproduction and influence thrips herbivory over egg predation when both resources are available. Implications of this study highlight the use of thiamethoxam soybean seed treatment as a potential contributor to increased spider mite populations, thrips reduced role as spider mite predator, and increased role as herbivorous pest.
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Ako, Mouhoube. "Impact assessment of neonicotinoid insecticides on the reproductive biology of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae)." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=983765944.
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Khan, Inamullah. "Aspects of the biology of the ladybird beetle Stethorus vagans (Blackburn) (Coleoptera: Coccinellidae)." Thesis, View thesis, 2000. http://handle.uws.edu.au:8081/1959.7/779.
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This thesis reports laboratory and field investigations on the aspects of biology of the Stethorus vagans, an Australian ladybird that feeds on all stages of two-spotted mite, Tetranychus urticae. Aspects of the biology of S. vagans were studied in the laboratory at constant and fluctuating temperatures. They regularly fed on all stages of T. urticae and there was no significant difference in male and female longevity at different temperatures. For field studies potted French bean plants infested with T. urticae were exposed in the field. Adult S. vagans was found to consume a range of alternative prey if the primary host was not available, but only one of the alternative hosts had the potential to support reproduction. Time partitioning behaviour and prey consumption rates were assessed, and how S. vagans located their prey was investigated. S. vagans exhibited many of the attributes of an effective biological control agent such as high reproductive level, location of prey at low levels, reproduction at low densities, and ability to feed on alternative hosts. It is concluded that S. vagans has a number of characteristics likely make them useful as a natural enemy of T. urticae
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Donahue, Daniel Joseph. "Oviposition and dispersal responses of the two spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) to fenvalerate and permethrin residues in soybeans Glycine max (L) Merrill." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/50077.
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Laboratory experiments were conducted to evaluate Tetranychus urticae Koch dispersal response to fenvalerate and permethrin. A petri dish spider mite trap which allows the partitioning of the dispersal response into spindown and walkoff categories was developed. Fenvalerate induced the more severe dispersal response.
A greenhouse experiment was conducted to evaluate Tetranychus urticae oviposition site selection in response to residues of fenvalerate and permethrin, at two levels of residue deposition. When pyrethroid-free leaf surface was available, nearly all eggs were found on the untreated surface, away from the pyrethroid residues. When pyrethroid-free leaf surface was not available, a substantial number of eggs were found suspended by silk threads above the treated surface. The results were found to be in agreement with the general pyrethroid avoidance hypothesis.
A series of greenhouse experiments were conducted to evaluate Tetranychus urticae oviposition response following impingement, and contact with residues of fenvalerate and permethrin. In all instances the pyrethroids were found to reduce the number of eggs oviposited. Mites recovered after several days, and oviposition returned to normal. The results did not lend support to the hormoligosis hypothesis of insecticide induced mite outbreaks.
Field and greenhouse experiments were conducted to evaluate Tetranychus urticae oviposition response, over time, to soybeans which have received an application of fenvalerate of permethrin. The pyrethroids did not alter the soybeans in a way which improved the quality of the plant as a resource for increased levels of spider mite oviposition.<br>Master of Science<br>incomplete_metadata
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Castro, Thiago Rodrigues de. "Abundance, genetic diversity and persistence of Metarhizium spp. fungi from soil of strawberry crops and their potential as biological control agents against the two-spotted spider mite Tetranychus urticae." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-05072016-142832/.
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The growing demand for strawberries has imposed challenges, especially regarding the control of pests. Many farmers report problems with reduced chemical control efficiency, probably due to selection of resistant populations of insects and mites. An alternative is the use of biological control using pathogenic fungi as a tool in integrated pest management. Metarhizium spp. (Hypocreales: Clavicipitaceae) are generalist entomopathogenic fungi with worldwide distribution and can cause diseases in a large number of hosts. Many studies on the development of Metarhizium as a biological control agent were performed, but this bulk of knowledge is in remarkable contrast to the lack of research on the fundamental ecology of Metarhizium in agroecosystems. This thesis aimed to evaluate the establishment, persistence and dispersal of these entomopathogenic fungi in strawberry crop soil in Inconfidentes, Minas Gerais, Brazil; and to study the diversity and abundance of species of Metarhizium isolated from organic and conventional strawberry crop soils, and the field margins in Brazil and Denmark. The effectiveness of new species of Metarhizium recently found in Brazil, was evaluated against two spotted spider mite, Tetranychus urticae. Applied isolates of M. anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) were able to persist for up to 12 months after the application within the soil, and disperse to other plots and colonize the rhizosphere of strawberry plants. In the plots where ESALQ1037 and ESALQ1426 were applied, 25% and 87.5% of the isolates recovered after 12 months consisted of the same isolates inoculated. A new taxonomically unassigned lineage, referred to as Metarhizium sp. Indet. 5 in this study, was found in strawberry crop margins. The dominant species of Metarhizium in Brazil and Denmark was Metarhizium robertsii and M. brunneum respectively. Further, Metarhizium pemphigi was first detected in Denmark in this study. Soil in organically grown strawberries harbored a more diverse population of Metarhizium spp. compared with conventionally grown strawberries. These studies showed for the first time the potential of new species of Metarhizium as spider mite biological control agents, the lowest median lethal time (LT50 = 4 ± 0.17 days) was observed in mites treated with the isolate ESALQ1638 of Metarhizium sp. indet. 1. The best isolates were ESALQPL63 of B. bassiana, ESALQ1608 and ESALQ1638 of Metarhizium sp. indet. 1 and ESALQ3069 and ESALQ3222 of M. pingshaense based on the survival curve, total mortality, percentage of sporulated cadavers and LT50. Knowledge of the diversity of Metarhizium spp. and persistence in strawberry soil generated in this study may be useful in developing conservation strategies and maximize the natural biological pest control.<br>A crescente demanda por morangos vem impondo desafios, especialmente quanto ao controle das pragas. Muitos agricultores relatam problemas com a redução da eficiência do controle químico, provavelmente devido à seleção de populações resistentes de insetos e ácaros. Uma alternativa é o uso de controle biológico com fungos entomopatogênicos como ferramenta dentro do manejo integrado de pragas. Metarhizium spp. (Hypocreales: Clavicipitaceae), são fungos entomopatogênicos generalistas com distribuição cosmopolita e que podem causar doenças em um grande número de hospedeiros. Muitos estudos sobre o desenvolvimento de Metarhizium como agente de controle biológico foram realizados, mas este leque de conhecimento está em contraste com a notável falta de investigação sobre a ecologia de Metarhizium nos agroecossistemas. Esta tese teve como objetivo avaliar o estabelecimento, persistência e dispersão destes fungos entomopatogênicos em solo de morangueiro em Inconfidentes, Minas Gerais, Brasil; bem como estudar a diversidade e abundância de espécies de Metarhizium isolados do solo de cultivos orgânico e convencional de morangueiro, e das margens das plantações no Brasil e Dinamarca. A eficácia de novas espécies de Metarhizium, encontradas recentemente no Brasil, foi avaliada contra o ácaro rajado, Tetranychus urticae. Os isolados inoculados de M. anisopliae (ESALQ1037) e M. robertsii (ESALQ1426) foram capazes de persistir por até 12 meses após a aplicação no solo, além de dispersar para outras parcelas e colonizar a rizosfera dos morangueiros. Nas parcelas onde ESALQ1037 e ESALQ1426 foram aplicados, 25% e 87,5% dos isolados recuperados após 12 meses consistiam dos mesmos isolados inoculados. Uma nova linhagem não taxonomicamente identificada, referida neste trabalho como Metarhizium sp. Indet. 5, foi encontrada nas margens de morangueiros cultivados. A espécie dominante de Metarhizium no Brasil e Dinamarca foi Metarhizium robertsii e M. brunneum, respectivamente. Além disso, Metarhizium pemphigi foi detectado pela primeira vez na Dinamarca neste estudo. Solos de cultivo orgânico de morangueiro em geral apresentaram uma diversidade maior de Metarhizium do que solos de cultivos convencionais. Estes estudos revelaram pela primeira vez o potencial de novas espécies de Metarhizium como agentes de controle biológico do ácaro rajado, sendo o menor tempo letal mediano (TL50= 4 ± 0.17 dias) observado em ácaros tratados com o isolado ESALQ1638 de Metarhizium sp. indet. 1. Os melhores isolados foram ESALQPL63 de B. bassiana, ESALQ1608 e ESALQ1638 de Metarhizium sp. indet. 1 e ESALQ3069 e ESALQ3222 de M. pingshaense baseado na curva de sobrevivência, mortalidade total, porcentagem de cadáveres esporulados e TL50. O conhecimento da diversidade de Metarhizium spp. e persistência em solos de morango, gerados neste estudo, poderão ser úteis no desenvolvimento de estratégias de conservação e maximizar o controle biológico natural de pragas.
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BORN, Flávia de Souza. "Atividade de óleos essenciais de plantas das famílias Burseraceae, Lamiaceae, Rutaceae e Verbenaceae em Tetranychus urticae Koch e Neoseiulus californicus (McGregor)." Universidade Federal Rural de Pernambuco, 2012. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6048.
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Previous issue date: 2012-02-01<br>Two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), has been controlled mainly chemical synthetic acaricides. The use of essential oils can be an alternative to this method of control. The aim of this study was to determine the effect of essential oils from plants of Families Burseraceae, Lamiaceae, Rutaceae and Verbenaceae against T. urticae and the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). Repellent and toxic activities of the oils were determined and compared to eugenol. Toxicity was evaluated by fumigation and residual effect in the laboratory and by direct contact in a greenhouse. The results showed that the oils of Ocimum basilicum L. and Thymus vulgaris L. were the most repellent, with RC50 = 3.43 x 10-7 and 2 x 10-4 μL/mL, respectively. The toxicity against eggs of T. urticae revealed T. vulgaris, Rosmarinus officinalis L., Citrus reticulata Blanco and O. basilicum oils as more active. Estimates of mortality concentration curves for fumigation of adult females of T. urticae revealed that was more toxic eugenol, with LC50 = 4 x 10-3 μL/L air. The test results showed that residual C. reticulata, T. vulgaris and O. basilicum oils present the same toxicity observed for eugenol. The toxicity tests to N. californicus indicated that all the oils are selective fumigation and that the O. basilicum, R. officinalis and C. reticulata oils were more selective by residual effect. The relative toxicity of the individual constituents of the essential oils and their contribuition to the acaricidal activity on T. urticae are also discussed. The highest average mortality on T. urticae in the greenhouse after 72 h of exposure were 100%, 98.85% and 96.59%, promoted by Citrus sinensis Osbek x Citrus reticulata Blanco, R. officinalis and Lippia gracilis Schauer oils, respectively.<br>O ácaro rajado, Tetranychus urticae Koch (Acari: Tetranychidae), tem sido controlado principalmente com acaricidas químicos sintéticos. O uso de óleos essenciais pode ser uma alternativa a esse método de controle. O objetivo deste trabalho foi determinar o efeito de óleos essenciais de plantas das Famílias Burseraceae, Lamiaceae, Rutaceae e Verbenaceae sobre T. urticae e o ácaro predador Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). As atividades repelente e tóxica dos óleos foram determinadas e comparadas ao eugenol. A toxicidade foi avaliada por fumigação e efeito residual, em laboratório e por contato direto em casa de vegetação. Os resultados demonstraram que os óleos de Ocimum basilicum L. e Thymus vulgaris L. foram mais repelentes, com CR50 de 3,43 x 10-7 e 2 x 10-4 μL/mL, respectivamente. A toxicidade sobre ovos de T. urticae revelou os óleos de T. vulgaris, Rosmarinus officinalis L., Citrus reticulata Blanco e O. basilicum como mais ativos. As estimativas das curvas de concentração mortalidade para fumigação sobre fêmeas adultas de T. urticae revelaram que eugenol foi mais tóxico, com CL50 de 4 x 10-3 μL/L de ar. Os resultados dos testes de efeito residual demonstraram que os óleos de C. reticulata, T. vulgaris e O. basilicum apresentaram a mesma toxicidade observada para o eugenol. Os testes de toxicidade a N. californicus indicaram que todos os óleos foram seletivos por fumigação e os óleos de O. basilicum, R. officinalis e C. reticulata foram os mais seletivos por efeito residual. A toxicidade relativa de constituintes individuais dos óleos e sua contribuição para a atividade sobre T. urticae também são discutidos. As maiores médias de mortalidade sobre T. urticae em casa de vegetação após 72 h de exposição foram de 100%, 98,85% e 96,59%, promovidas pelos óleos de Citrus sinensis Osbek x Citrus reticulata Blanco, R. officinalis e Lippia gracilis Schauer, respectivamente.
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Bowie, Mike H. "Evaluation of image analysis for studing mite behaviour." Lincoln University, 1996. http://hdl.handle.net/10182/1056.
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The aim of this study was to investigate the usefulness of image analysis for studying mite behaviour. Image analysis was used to convert video recordings of mites' locomotory behaviour into a series of x,y coordinates that, when joined, closely resemble the paths of mites. The coordinates were also used to calculate walking speed, direction of travel, turning frequency, turn bias and tortuosity. Two experimental arenas were developed and used to study the movement of three mite species: 1) a leaf disc arena for two-spotted spider mite, Tetranychus urticae Koch and European red mite, Panonychus ulmi (Koch); and 2), a cover-slip/tack-trap arena for Typhlodromus pyri Scheuten. Two-spotted spider mite exhibited a change in locomotory behaviour through a 48 minute period. Mites exhibited a significant decline in distance travelled, whereas the mean stationary time (per four minute interval) more than doubled, and the duration of stationary events increased steadily over the same period. A reduction in sampling frequency of mite coordinates from one per second to one every two seconds and every four seconds produced a 5% and 12% 'loss' in path length respectively. Sample period length was shown to greatly influence the results produced for some of the mean parameters calculated, however, a reduction in sample length from 3000 to 1500 coordinates was not considered to cause a major loss in information. The influence of the inherent mite movement could not be ignored and made it difficult to make decisions on the 'best' sample length to use. Some strong correlations were found between parameters used to analyse mite locomotory behaviour. In particular, arithmetic mean vector length, speed, total stationary time and total distance travelled were significantly correlated with each other. Mean angular deviation and weighted mean vector length, which both measure the degree of clustering around the mean heading angle, were strongly negatively correlated. Parameters which differentiated between 'straight' and 'tortuous' mite movement were found to be mean meander, absolute mean turn and fractal dimensions. Mean meander was thought to be the most 'powerful', while coefficient of a straight line, a commonly used parameter for measuring tortuosity, did not significantly differentiate between the two different behaviours. Frequency distributions of turns and standard deviations of the three mite species were very similar. All three species had a slight bias to turning right (clockwise) rather than to the left (counter-clockwise) and for each species certain angles occurred more often than would be expected in a 'perfect' normal distribution. A similar pattern also occurred with the frequency distribution of two-spotted spider mite heading angles, in that angles which were expected to occur more often, did not, and vice versa. The potential to use saturated salt solutions to control relative humidity on the arena was` demonstrated and indicated that relative humidity is likely to have an important influence on mite behaviour. Two-spotted spider mites appeared to move more quickly in an attempt to escape the unfavourable, extreme (10% and 95% R.H. at 25°C) moisture conditions. All three mite species displayed a characteristic edge-walking behaviour around the arenas. However, when 'edge' and 'non-edge' behaviours were compared, mean meander was the only parameter (of the parameters tested) which gave a significant difference. Behavioural responses of European red mite and T. pyri to sub-lethal (field rate) esfenvalerate were investigated and the results indicated that these mites did not seek the unsprayed halves of the arenas during the first 48 minutes. However, significant differences in most behavioural parameters to esfenvalerate residues were found with European red mite when whole arenas were compared. Image analysis is an extremely useful research tool for studying mite behaviour because of its ability to measure many parameters quickly. Careful choice of the environmental conditions, the sampling framework, and interpretation of data is essential for meaningful results.
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Esteca, Fernanda de Cássia Neves. "Manejo integrado de pragas na cultura do morangueiro no sul de Minas Gerais." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-02052017-100726/.
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O sul de Minas Gerais é a principal região produtora de morangos (Fragaria x ananassa Duch.) no Brasil. O ácaro-rajado, Tetranychus urticae Koch (Acari: Tetranychidae), é considerado uma das principais pragas do morangueiro no Brasil e em vários países. Uma prática importante na cultura do morango refere-se à cobertura de solo, usualmente realizada com filme de polietileno, porém além de ser caro gera resíduos muito persistentes no ambiente. Objetivou-se com este trabalho comparar a resistência de oito genótipos de morango (\'Albion\', \'IAC Guarani\', \'IAC Princesa Isabel\', \'Oso Grande\', IAC T-0104, IAC 12, IAC 4 e IAC 1.13) ao ácaro-rajado; determinar o efeito da cobertura de solo (com a polpa de café desidratada, conhecida como palha de café) nas pragas/ patógenos e ácaros predadores desta cultura; comparar a ocorrência de pragas, patógenos e inimigos naturais entre um cultivo orgânico e outro convencional de morango. Os resultados obtidos indicaram que \'IAC Princesa Isabel\', IAC T-0104 e IAC 12 são resistentes, IAC 1.13 e IAC 4 apresentam resistência moderada e \'IAC Guarani\', \'Oso Grande\' e \'Albion\' são suscetíveis ao ácaro-rajado. \'Oso Grande\' e \'Albion\' são bastante utilizadas pelos produtores do sul de Minas Gerais. O uso de palha de café aumentou o número de predadores edáficos, tanto no solo dos canteiros (campo) e em vasos (laboratório) como em folíolos de morangueiro. O Gamasina Proctolaelaps pygmaeus (Müller) (Melicharidae) foi visto sobre morangueiros, principalmente no período noturno. Maior número de ácaro-rajado e maior severidade de doenças foram observados em plantas cultivadas em solo coberto com polietileno. Além disso, foi maior o nível de infecção de ácaro-rajado pelo fungo Neozygites floridana (Weiser e Muma) em plantas cultivadas em solo coberto com palha de café. Não foi observada diferença significativa entre a produtividade da cultura em solo coberto com polietileno e em solo coberto com palha seca de café. Os resultados da comparação da ocorrência de ártropodes e patógenos entre sistema orgânico e convencional mostraram menor ocorrência de ácaro-rajado e predadores em cultivo de morangueiro convencional, porém ocorrência considerável de tripes, mosca-branca e mofo cinzento. A incidência de dendrofoma e mancha de pestalotia foi a mesma nos dois sistemas de cultivos. Os resultados sugerem a conveniência de se continuar o processo de desenvolvimento dos genótipos que se mostraram menos afetados pelo ácaro-rajado, para que estes possam no futuro ser utilizados pelos produtores, e a condução de estudos complementares, que avaliem o desempenho de cultivos em sistema orgânico que incorporem o uso da palha de café para a cobertura do solo.<br>The southern of Minas Gerais is the main region producing strawberries (Fragaria x ananassa Duch.) in Brazil. The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is considered one of the main strawberry pests in Brazil and in several countries. An important practice in strawberry cultivation refers to soil cover, which is usually made with polyethylene film, but it is expensive and generates very persistent residues in the environment. The objective of this study was to compare the resistance of eight strawberry genotypes (\'Albion\', \'IAC Guarani\', \'IAC Princesa Isabel\', \'Oso Grande\', IAC T-0104, IAC 12, IAC 4 and IAC 1.13); to determine the effect of soil cover (with dehydrated coffee pulp, known as coffee straw) on the pests mites/ pathogens and predatory mites of this crop; to compare the occurrence of pests, pathogens and natural enemies between an organic and a conventional strawberry crop. The results indicated that \'IAC Princesa Isabel\', IAC T-0104 and IAC 12 are resistant, IAC 4 and IAC 1.13 are moderately resistant, and \'IAC Guarani\', \'Oso Grande\' and \'Albion\' are susceptible to the two-spotted spider mite. \'Oso Grande\' and \'Albion\' are widely used by producers in the southern of Minas Gerais. The use of coffee straw increased the number of edaphic predators, both in the soil beds (field) and in pots (laboratory) as well as in strawberry leaflets. The Gamasina Proctolaelaps pygmaeus (Müller) (Melicharidae) was seen on strawberry leaftlets, mainly in the nocturnal period. Higher numbers of the two-spotted spider mites and disease severity were observed in plants grown on soil covered with polyethylene. In addition, the level of the two-spotted spider mite infected by the fungi Neozygites floridana (Weiser and Muma) was higher in plants cultivated in soil covered with coffee straw. No significant difference was observed between yield in soil covered with polyethylene and in soil covered with dry coffee straw. The results of the comparison of the occurrence of arthropods and pathogens between the organic and conventional systems showed fewer occurrences of the two-spotted spider mites and predators in conventional strawberry cultivation, but considerable occurrence of thrips, whitefly and gray mold. The incidence of dendrophoma and leaf spots caused by pestalotia was the same in both cropping systems. The results suggest the convenience to continue the development process of the genotypes that were less affected by the two-spotted spider mite, which could be used in the future by producers, and the conduction of complementary studies to evaluate the performance of crops in organic system that incorporate the use of coffee straw as soil coverage.
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NASCIMENTO, Aline Fonseca do. "Atividade do óleo essencial de frutos de Schinus terebinthifolius raddi (anacardiaceae) em Tetranychus urticae koch (Acari: Tetranychidae) e Rhyzopherta dominica fabricius (Coleoptera: Bostrichidae)." Universidade Federal Rural de Pernambuco, 2012. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5951.
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Previous issue date: 2012-02-01<br>Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq<br>The search for new biologically active compounds to arthropods seems to have an important role in integrated pest management. Schinus terebinthifolius, popularly known as pepper tree is a kind of abundance in Pernambuco and due to their biological properties is widely used in folk medicine. This study aimed to determine the chemical constituents of essential oils of ripe fruits (OORF) and unripe (OOUF) mastic and evaluate the potential acaricide and insecticide through lethal and sublethal effects on Tetranychus urticae and Rhyzopherta dominica . Analyzed by GC / MS revealed the limonene as the main constituent in both oils (OOUF = 44,1 ± 1,3%; OORF = 31,8 ± 1,2%). The residual contact and fumigant action of these oils on T. uticae revealed OOUF the most active in fumigation (LC50 = 1,46 μL / L of air), while OEFM was more active in the tests of the contact petri dishes closed and opened petri dishes (LC50 μL/L/cm² = 3,04) and did not differ statiscally from eugenol. These oils exhibited significant repellent activity against T. urticae compared with eugenol. For R. dominica fumigation test showed no statistical difference between the two oils, but both were more effective in the exposure period of 72h. Limonene the main constituent of OOUF and OORF, showed the same level of toxicity compared to the essential oils. Tests with blends prepared with the major and minor constituents of these oils indicated that limonene is the major contributor to toxicity obtained for OOUF and OORF. The OOUF was repellent to 25, 35 and 45 μL/2g) and the oil of OORF proved attractive in the lower concentration tested (15 μL/2g) and repellent at the highest (30 and 50 μL/2g).<br>A busca por novos compostos biologicamente ativos aos artrópodes tem um papel importante no manejo integrado de pragas. Schinus terebinthifolius, conhecida popularmente como aroeira é uma espécie de grande abundância o estado de Pernambuco e, devido as suas propriedades químicas e biológicas, é amplamente utilizada na medicina popular. Este trabalho tem por objetivo determinar os constituintes químicos de óleos essenciais dos frutos maduros (OEFM) e imaturos (OEFI) de aroeira e indicar o potencial acaricida e inseticida, a partir dos efeitos letais e subletais, sobre Tetranychus urticae Koch (Acari: Tetranychidae) e Rhyzopherta dominica Fabr. (Coleoptera: Bostrichidae). A análise realizada por GC/EM revelou o limoneno como constituinte majoritário em ambos os óleos (OEFI = 44,1 ± 1,3%; OEFM = 31,8 ± 1,2%). A ação fumigante e contato residual desses óleos sobre T. urticae revelou que o OEFI foi mais ativo por fumigação (LC50 = 1,46 μL/L de ar), enquanto que o OEFM foi mais ativo nos testes de contato com placas fechadas do que placas abertas (LC50 = 3,04 μL/L/cm2) e não diferiram estatisticamente do eugenol. Estes óleos exibiram significante atividade repelente a T. urticae comparados com o eugenol. Para R. dominica no teste de fumigação não houve diferença estatística entre os óleos, mas ambos se mostraram mais eficazes no período de exposição de 72h. O limoneno, principal constituinte dos OEFI e OEFM, apresentou o mesmo nível de toxicidade quando comparado aos óleos essenciais. Testes com blendas preparadas com os constituintes principais e minoritários desses óleos indicaram que o limoneno foi o composto que mais contribuiu para a toxicidade obtida para o OEFI e o OEFM. O OEFI foi repelente a 25, 35 e 45 μL/2g) e o OEFM se mostrou atraente na menor concentração (15 μL/2g) e repelente nas mais altas (30 e 50 μL/2g).
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Moro, Larissa Benardino. "Biologia e potencial de controle de Tetranychus urticae Koch (Acari: Tetranychidae) com fungos entomopatogênicos em mamoeiro." Universidade Federal do Espírito Santo, 2009. http://repositorio.ufes.br/handle/10/6615.
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Previous issue date: 2009-12-10<br>O Brasil é o primeiro produtor mundial e terceiro exportador de mamão Carica papaya L., com destaque para o Estado do Espírito Santo que responde a 70% da exportação. As condições climáticas necessárias ao desenvolvimento do mamoeiro são altamente favoráveis para a ocorrência de problemas fitossanitários, sendo a espécie Tetranychus urticae (KOCH, 1836) (Acari: Tetranychidae) uma das pragas-chave, infestando o mamoeiro durante todo o ano. Este ácaro tem sido controlado por agrotóxicos, mas o uso em larga escala destes produtos pode levar ao rápido desenvolvimento de resistência, além de serem danosos ao ambiente. A utilização de cultivares resistentes e de fungos entomopatogênicos são alternativas de controle para esta praga, reduzindo os riscos de resistência do ácaro a acaricidas e a toxicidade ao ambiente. Este trabalho avalia o desenvolvimento e reprodução de T. urticae em cultivares de mamão e verifica se essas cultivares interferem na patogenicidade de Beauveria bassiana, Metarhizium anisopliae e Lecanicillium longisporum. Foram utilizados quatro cultivares de mamão, dois do grupo Formosa (Tainung 01 e Calimosa) e dois do grupo Solo (Golden e Sunrise). Para iniciar o bioensaio foi transferida uma fêmea fertilizada de T. urticae ao disco de folhas e a mesma foi retirada após um período de 12 horas, deixando um ovo por disco, que foi avaliado a cada 12h, registrando-se o período de incubação, duração do estágio de imaturo, longevidade e fecundidade dos adultos e viabilidade desses estágios. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey, a 5% de probabilidade. Para o bioensaio com fungos entomopatogênicos foram utilizadas fêmeas adultas de T. urticae provenientes da criação sobre feijão-de-porco Canavalia ensiformis (L.) e ácaros que permaneceram sobre folhas das cultivares de mamão por pelo menos uma geração. Foram transferidas dez fêmeas para as placas de Petri com disco de folha de C. ensiformis ou de C. papaya com a face abaxial voltada para cima sobre uma camada de algodão hidrófilo umedecida. Em seguida, os ácaros foram pulverizados com suspensões de conídios em Torre de Potter, utilizando-se volume de 5 mL de suspensão 5x107 conídios.mL-1. As suspensões de conídios foram preparadas a partir das formulações comerciais (Boveril® B. bassiana; Metarril® M. anisopliae; Vertirril® L. longisporum). Foi avaliada a mortalidade corrigida e confirmada. A duração do período de ovo na variedade Tainung 01 foi menor (4,0 dias) em relação às outras variedades. O mesmo ocorreu para a duração dos estágios de larva, protoninfa e período ovo-adulto entre as variedades analisadas, sendo maior para as variedades Calimosa, Sunrise e Golden. Esses resultados indicam que as variedades de mamão, Tainung 01, Calimosa, Sunrise e Golden são bons hospedeiros para T. urticae com destaque para Tainung 01, pois esta apresentou menor duração aos estágios de ovo, larva, protoninfa e período ovo-adulto. Os resultados indicaram que os fungos entomopatogênicos comerciais são promissores para o controle de T. urticae em mamoeiro. Testes de estimativa da CL50 e bioensaios em semi-campo e campo são necessários para a adoção desta tática de controle microbiano<br>Brazil is the worlds largest producer and third exporter of Papaya Carica papaya L., especially the state of Espírito Santo, which accounts for about 70% of exports. Climatic conditions necessary to the development of papaya are also highly favorable for the occurrence of phytosanitary problems, and the species Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) one of the key pest, infesting papaya plant throughout the year. This mite has been controlled by pesticides, but the widespread use of these products can lead to rapid development of resistance, besides being harmful to the environment. The use of resistant cultivars and entomopathogenic fungi are alternatives to control this pest, reducing the risk of mite resistance to acaricides and also the toxicity to the environment. The study was conducted to evaluate the development and reproduction of T. urticae in papaya cultivars and to verify if these cultivars interfere with the pathogenicity of Beauveria bassiana, Metarhizium anisopliae and Lecanicillium longisporum. Were assayed four varieties of papaya, two of the group "Formosa" (Tainung 01 and Calimosa) and two from the "Solo" (Golden and Sunrise). To initiate the bioassay, it was transferred a fertilized female T. urticae to a leaf dish and the female was removed after a period of 12 hours, leaving one egg per disc, that was evaluated every 12 hours recording the incubation period, length of immature stage, longevity and fecundity of adults and viability of these stages. Data were subjected to analysis of variance and means compared by Tukey test at 5% probability. For the bioassay with entomopathogenic fungi were used adult females of T. urticae from the rearing of jack bean Canavalia ensiformis (L.) and mites that remained on leaves of cultivars of papaya for at least a generation. Ten females were transferred to Petri dishes with leaf disk of C. ensiformis or C. papaya with the abaxial side up on a layer of cotton wool moistened. After that mites were sprayed with conidial suspension in a Potter Tower, using a volume of 5 mL of inoculum suspension 5x107 conidia.mL-1. Conidial suspensions were prepared from the commercial formulations (Boveril ® B. bassiana, Metarril ® M. anisopliae; Vertirril ® L. longisporum). We evaluated the mortality corrected and confirmed. The duration of the egg in the variety Tainung 01 was smaller (4.0 days) than to the other varieties. The same occurred for the duration of the larval stages, protonymph and egg-adult period between the varieties analyzed, being higher for varieties Calimosa, Sunrise and Golden. These results indicate that the varieties of papaya, Tainung 01, Calimosa, Sunrise and Golden are good hosts for T. urticae, especially Tainung 01, which showed a shorter duration of the egg, larva, protonymph and egg-adult period. The results also indicate that the fungi are promising for commercial control of T. urticae in papaya. Tests of estimation of the CL50 bioassays and in semi-field and field are required to use this tactic of microbial control
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Rethwisch, Michael D., Krystyl Bolin, Jessica L. Grudovich, Jessica Wellman, Dyke Charles Van, Juan Vingochea, Marlo Barron, and Mark Reay. "Effect of two-spotted spider mites and miticides on alfalfa hay produced for a late May cutting." College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/203870.
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Three miticide treatments (milbemectin, clarified neem oil, and chlorpyrifos plus dimethoate) were compared with an untreated check to obtain information on the effects of twospotted spider mite (Tetranychus urticae) feeding on alfalfa yields, quality and economics, as well as crop responses to miticides. Mite infested alfalfa was treated just prior to first irrigation after cutting in spring 2003, and numbers of spider mites and western flower thrips (Frankliniella occidentalis) were obtained at weekly intervals thereafter for the next seven weeks. Data for plant parameters (stem widths, numbers of leaves, internode lengths) were obtained at harvest, as were hay yields and quality. The milbemectin treatment resulted in quickest reduction of spider mites (88.5% at 5 days after application) and also resulted in significantly higher yields than the untreated check (0.18 tons of hay/acre), attributed to the longer internodes and resultant tallest plants and significantly thicker stems than the untreated check. Clarified neem oil and chlorpyrifos plus dimethoate treatments did not control spider mites as quickly as milbemectin and yields were increased by only 0.04-0.05 tons hay per acre in this experiment compared with the untreated check. These two treatments also differed in their effects on stem widths and internode lengths, indicating that some results noted were a result of interactions of miticides with alfalfa as well as spider mite control.
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Lawanprasert, A. "Response of hop cultivars to two-spotted spider mite infestation." Thesis, 1994. https://eprints.utas.edu.au/20335/7/whole_LawanprasertApichart1995.pdf.
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The two-spotted spider mite (TSSM), Tetranychus, urticae Koch, is
one of the most serious pests in regions where hops,Humu/us lupulus
L., are grown. Resistant cultivars would be ideal to reduce plant damage
caused by this pest. Studies on the biological interaction between
cultivated hop cultivars and TSSM were conducted over three growing
seasons to gain a greater understanding of plant mechanisms involved in
the response to mite attack under both natural and controlled
environmental conditions.
In field observations, the results revealed a generalised pattern of
growth and decline in naturally occurring mite populations infesting
commercial hops during the growing season. The mites peaked after
hops had formed the visible bases of inflorescences. Eggs were the
predominant stage for most of the season and stage-specific percentages
changed as the season progressed. The spatial and vertical distributions
of the mites for each stage also varied with time. Natural enemies did
not appear at levels sufficient to give control.
Studies on the susceptibility of different hop genotypes to artificial
and natural infestations by the mites indicated that all the genotypes
tested expressed an intermediate to highly susceptible reaction, with M26
(Huller Bitterer) being the most susceptible. Despite no outstanding
evidence of antibiosis, there were significant differences in susceptibility
among hop genotypes in terms of tolerance, non-preference and plant
avoidance in which plant growth exceeds the mite dispersive capacity.
Significant differences in mite densities between the hop cultivars of
European and American parentage were also detected in that the
European cultivar was more susceptible than the American.
Morphological variation in external and internal characteristics of
hop leaves were found among the genotypes studied. Significant
differences were found in ventral gland size, trichome density, trichome
size, length of trichomes, stomatal density, stomatal size and moisture
content. The morphological characteristics of the hop leaves collected
from the same genotype may vary significantly according to leaf age and
growing conditions. Under controlled conditions, none of these
morphological characteristics were found to influence TSSM population
reproductive parameters. In addition to genotypic effects, the findings demonstrated that
environmental factors did influence life history traits of TSSM. These
factors included temperature, relative humidity, light intensity and plant
variables.
Physiological and chemical responses of hop genotypes to mite
feeding damage were examined in field and glasshouse experiments.
Feeding damage by mites increased hop leaf resistance to CO2 uptake
through stomatal closure and decreased photosynthetic rates. The
stomatal response to infestation differed between cultivars. Analysis of
chemicals extracted from hop leaves indicated that phenolics, alkaloids
and volatile compounds in infested leaves were qualitatively and
quantitatively similar to those detected in undamaged control leaves.
Hop-canopy microenvironments do play an important role in
seasonal population development of two-spotted spider mites. This role
was amplified by hop susceptibility to the mites. For the hop genotypes
studied; the populations of mites, and 'their predators, tended to increase
more rapidly on sparsely leaved canopies than on densely leaved
canopies. The overall results gtrongly suggest that TSSM performance
was mainly regulated by the microenvircinments that exist within the
canopies of different cultivars with (1) sparsely leaved canopies favouring
population increase and (2) reduced temperature and light and increased
humidity within dense canopies limiting population increase.
22
Gatarayiha, Mutimura Celestin. "Biological control of the two-spotted spider mite, Tetranychus urticae Koch (Acari : tetranychidae)." Thesis, 2009. http://hdl.handle.net/10413/650.
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The two-spotted spider mite (TSM), Tetranychus urticae Koch, is an important pest of many greenhouse and field crops worldwide. The development of resistance in TSM populations to chemical acaricides, allied with public health concerns about pesticide residues, has motivated the search for alternative control measures to suppress the pest. Hyphomycetous fungi are promising agents for mite control and the fungus Beauveria bassiana (Bb) (Balsamo) Vuillemin was investigated in this study as a biocontrol agent. The principal objectives of this study comprised: a) screening Bb strains for their pathogenicity against T. urticae; b) testing the effect of adjuvants on the efficacy of Bb; c) studying the effect of plant type on persistence of Bb and the efficacy of control of Bb against T. urticae; d) evaluating the field efficacy of Bb applications against T. urticae; e) testing the compatibility of Bb with selected fungicides; and f) assessing the synergy between Bb and soluble silicon for T. urticae control. Screening bioassays of sixty-two strains of Bb identified the two most effective strains, PPRI 7315 (R289) and PPRI 7861 (R444), that caused mortality levels of more than 80% of adult mites at 9 d post-inoculation with 2 × 108 conidia ml-1. These strains performed significantly better than the Bb commercial strain PPRI 5339, in laboratory bioassays. The two strains also attacked mite eggs, causing 53.4% and 55.5% reduction in egg hatchability at 2 × 108 conidia ml-1 respectively. However, PPRI 7861 showed relatively higher production of conidia in culture and was, therefore, selected for further trials under greenhouse and field conditions. Greenhouse evaluations of the effects of two adjuvants (Break-thru® and a paraffin oil-based emulsion) on efficacy of Bb demonstrated a higher efficacy of the biocontrol agent (BCA) when it was applied with Break-thru® or the oil solution than with water alone. Moreover, Bb conidia applied in Break-thru® solution resulted in greater control of TSM than conidia applied in the mineral oil. There was also a dose-response effect and the control of TSM by Bb increased when the concentration of conidia was increased. The control of TSM by Bb in beans (Phaseolus vulgaris L), cucumber (Cucumis sativus L.), eggplant (Solanum melongena L.), maize (Zea mays L.) and tomato (Solanum lycopersicum L.) was tested in greenhouse trials. On these crops, the persistence of conidia declined over time. The rate of decline was significantly higher on maize. However, TSM mortality was positively correlated with the amount of conidia deposited on leaves immediately after spraying, rather than their persistence over time. Higher levels of mortality of TSM due to Bb application were observed on beans, cucumber and eggplants, suggesting that the type of crop must be taken into consideration when Bb is applied as a BCA. Field efficacy of Bb against mites was evaluated in two trials on eggplants. Based on assessment of population densities of mites and leaf damage assessments; both trials showed that the strain PPRI 7861 controlled TSM in the field. Two commonly used fungicides, azoxystrobin and flutriafol, were investigated in vitro tests on culture medium and laboratory bioassays on detached bean leaves (Phaseolus vulgaris L.) for their effects on Bb. Azoxystrobin (a strobilurin) was less harmful to Bb while flutriafol was found to be inhibitory. Another important finding of this study was the substantial enhancement of Bb efficacy by soluble silicon. When Bb was combined with soluble Si, the control of TSM was better than when either of the two products was applied alone. Moreover, application of soluble Si as a plant fertilizer in hydroponic water nutrient increased accumulation of peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase enzymes in leaves of plants infested with TSM. Increased activity of these defense enzymes in leaves deters feeding behaviour of mites. We suggested that feeding stress renders them susceptible to Bb infection, which would explain the synergy observed between the two agents.<br>Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
23
Hung, Ming-Yi, and 洪明毅. "The Study of Entomopathogenic Fungi of Two-spotted Spider Mite and its Application on Strawberry in Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/78793451417770611871.
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24
Liao, Bao-Cheng, and 廖保成. "Evaluation of the efficacy of non-pesticide substances to control two spotted spider mite (Tetranychus urticae) on strawberry." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59554433696142803861.
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碩士<br>國立臺灣大學<br>昆蟲學研究所<br>100<br>Strawberry is an important crop of high economic value in Taiwan, and it is one of reasons farmers invest a lot of money to develop facility cultivation such as nethouses, greenhouses and plant factories. However, the crop is threatened by several tiny pests both in the field and greenhouses. Among them, the two-spotted spider mite (Tetranychus urticae) is one of the most common and serious pests of strawberry. Chemical control is a conventional method for controlling the mite, but there are some problems with using pesticides to control T. urticae. Pesticides can cause serious problems such as resistance in T. urticae populations and residues on the fruit. Therefore, it would be beneficial to find some safer and more efficient non-pesticide substances for pest control on strawberry. In this study, narrow-range oils, and wood-vinegar, soap, and sugar-vinegar solutions were tested for their efficiency in controlling T. urticae on facility-cultivated strawberries. The results of the dish test indicated that narrow-range oils and the soap solution at a 200-fold dilution produced the highest mortality rates among these non-pesticide substances with respective mortality rates of 58.3% and 61.7%, but these were lower than that of abamectin (98.3%). Moreover, in the potted strawberry test, mortality rates of narrow-range oils (88.3%) and the soap solution (86.7%) at a 200-fold dilution were very high after 72 h of treatment. In the control experiment, respective control rates for narrow-range oils and soap solution at a 200-fold dilution were 91.1% and 84.2%. This indicates that T. urticae was efficiently controlled using these substances. Moreover, results showed that the wood-vinegar solution at a 200-fold dilution produced a low mortality rate, but it still had the some control effect on the T. urticae population. The control rate with the wood-vinegar solution was 62%. It is suspected that some other factors suppress the population density of T. urticae. In the future, narrow-range oil and soap solutions will be applied to control mites on strawberries in greenhouses and plant factories.
25
Cao, Yong. "Biological and ecological studies of two spotted spider mite (Tetranychus urticae Koch) and its control on hops in Tasmania." Thesis, 1989. https://eprints.utas.edu.au/18968/1/whole_CaoYong1989_thesis.pdf.
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This study was initiated in March 1987 and completed in March 1989.
Aspects of the general biology and ecology of Two Spotted Spider Mite
(TSSM), Tetranychus urticae Koch, and its natural enemies in hop fields
were investigated in the years 1987-88 and 1988-89. The investigation found
that TSSM overwinters in hollow cavities of hop twigs in the litter around
hop rootstocks. In late August to early September TSSM becomes active to
lay eggs and progressively colonizes hop on the lower surface of hop leaves.
The teneral female mites of new generations were found to move upward
with elongation of hop vines.The distribution patterns of the mites on hops
vary with time and mite stage. In early or mid-March, mites move
downward along hop vines to seek overwintering refuges.
The native predatory mite, Amblyseius longispinosus (Evans), was
found to overwinter in the litter around the hop base. While the imported
predatory mite, Phytoseiulus persimilis Athias-Henriot, cannot survive the
Tasmanian winter.
The effects of TSSM feeding on hop production and the control of TSSM
on hops by various means were studied in the two consecutive seasons. If
unchecked, the mite can cause as much as 30% loss in cone production. The
loss is mainly due to the reduction in numbers of cones hop plants produce
under high mite feeding pressure. Damage was most often associated with
large numbers of immature TSSM. However, mite populations can be
effectively suppressed by either multiple application of Summer-oil/ Limesulphur,
or the release of predacious mite P. persimilis at appropriate time.
A tolerance to mite feeding by hop plants was demonstrated. If
insufficient numbers of cones are formed due to mite infestation, hop plants
will produce larger cones to achieve maximum production.
Two cultural activities can be effectively included into a TSSM control
programme. Ploughing hop fields in late August - early September, after
overwintering adults have moved onto notably thistles, can retard the build
up of TSSM populations. Furthermore frequent use of overhead sprinkler
irrigation of hop fields can result in suppression of TSSM populations.
Several simple ways of assessing TSSM densities on hops were assessed
in 1987-88 and were employed throughout this study. A 'modified counting
method' was developed for estimating mite densities using a mite-brushing
machine. Adult female mite densities were estimated in hop fields by the
naked eye and these counts related to total numbers of all mite stages.
In the phenology of the hop plant economic damage by mites was caused
through infestation during the flowering phase and not by infestation of the
earlier vegetation growth phase. Trial results indicated that application of
Summer-oil during the post-vegetation phase could provide a potential
alternative to conventional miticides.
26
Ako, Mouhoube [Verfasser]. "Impact assessment of neonicotinoid insecticides on the reproductive biology of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) / von Mouhoube Ako." 2006. http://d-nb.info/983765944/34.
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27
Xue, Yingen, University of Western Sydney, College of Health and Science, and School of Natural Sciences. "Effects of an nC24 agricultural mineral oil on tritrophic interactions between French bean (Phaseolus vulgaris L.), two-spotted mite (Tetranychus urticae Koch) and its predator, Phytoseiulus persimilis Athias-Henriot." 2007. http://handle.uws.edu.au:8081/1959.7/14036.
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A comprehensive evaluation of the effects of an nC24 agricultural mineral oil (AMO) on tritrophic interactions between French bean Phaseolus vulgaris cv. Redlands Pioneer [Fabales : Fabaceae ], two spotted mite (TSM) Tetranychus urticea Koch [Acari: Tetranychidea] and the predatory mite Phytoseiulus persimilus Atheus-Henriot [Acari: Phytoseiidae] was conducted under laboratory conditions.<br>Doctor of Philosophy (PhD)
28
Xue, Yingen. "Effects of an nC24 agricultural mineral oil on tritrophic interactions between French bean (Phaseolus vulgaris L.), two-spotted mite (Tetranychus urticae Koch) and its predator, Phytoseiulus persimilis Athias-Henriot." Thesis, 2007. http://handle.uws.edu.au:8081/1959.7/14036.
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A comprehensive evaluation of the effects of an nC24 agricultural mineral oil (AMO) on tritrophic interactions between French bean Phaseolus vulgaris cv. Redlands Pioneer [Fabales : Fabaceae ], two spotted mite (TSM) Tetranychus urticea Koch [Acari: Tetranychidea] and the predatory mite Phytoseiulus persimilus Atheus-Henriot [Acari: Phytoseiidae] was conducted under laboratory conditions.