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Fungal parasitism of cereal aphids in South Africa.Hatting, Justin Louis. 17 December 2013 (has links)
The Russian wheat aphid, Diuraphis noxia is one of the most destructive exotic
invaders of South Africa, capable of reducing individual wheat plant yields by up to
90%. Entomopathogenic fungi are important natural mortality factors associated with
this aphid in its Eurasian endemic habitats as well as in the United States and Canada;
their impact often exceeding that of predators and parasitoids.
The principal objectives of this study included (1) baseline characterization of the
aphid-pathogenic flora associated with aphids from South Africa, with special
reference to six common cereal aphids, (2) quantification of the comparative impact
of the different fungal species on the cereal-aphid complex in three different wheat
producing regions of South Africa, (3) field evaluation of the Hyphomycete
Beauveria bassiana against D. noxia on resistant wheat, (4) screening of six
fungicides for their potential usage in managing entomophthoralean epizootics within
greenhouse rearings of the Russian wheat aphid, and (5) development and evaluation
of a novel bioassay protocol for screening entomopathogenic Hyphomycetes against
D. noxia.
A total of nine species of fungi known to infect and kill aphid hosts were
collected, including the six entomophthoraleans, Pandora neoaphidis, Conidiobolus
thromboides, Conidiobolus obscurus, Entomophthora planchoniana, Conidiobolus
coronatus and Neozygites fresenii, and three Hyphomycetes, Beauveria bassiana,
Verticillium lecanii, and Paecilomyces farinosus. The former four
entomophthoraleans are considered first reports from this country. For the first time,
morphological characteristics of these nine South African-collected species are
visually depicted and techniques for their isolation and in vitro culture discussed.
Seven species of fungi were recorded from D. noxia, of which P. neoaphidis was
the most important, causing up to 50% mortality during the late season under dryland
conditions in the summer-rainfall region. Mycoses at epizootic levels, together with
the large diversity of fungal species recorded from this host, indicated a high level of
susceptibility to fungal infection. In contrast, infection of the oat aphid
Rhopalosiphum padi remained < 5% despite favourable numbers of hosts and
apparently suitable environmental conditions. This phenomenon strongly suggests
some level of low susceptibility to fungal infection in this species. Under irrigated conditions m KwaZulu-Natal, the rose-gram aphid
Metopolophium dirhodum was the predominant aphid but remained below economical
injury levels. Field surveys revealed that this aphid was effectively targeted by P.
neoaphidis and C. obscurus, and findings suggest that in some areas of South Africa
entomophthoralean fungi effectively suppress this aphid, negating the need for
insecticide applications.
On average, ca. 61% control of D. noxia on resistant wheat was observed
following an application of B. bassiana (5 x 10¹³ conidia per hectare) during the early
flag-leaf stage of the wheat. Efficacy of B. bassiana applications on younger plants
appeared to be influenced by the level of aphid activity, possibly explained by
secondary pick-up of inoculum by D. noxia. These findings accentuate the importance
of understanding the tritrophic relationship between host plant, pest and pathogen.
The fungicides copper oxychloride, mancozeb + oxadixyl, captab + metalaxyl,
bittertanol, iprodione, and mancozeb at a rate of 0.1% active ingredient moderately to
strongly inhibited C. thromboides vegetative growth (mean inhibition 81.1 %).
Mancozeb at concentrations of 10.0, 2.0, 1.25, 0.5, 0.08, and 0.016% was further
evaluated in vitro. The fungus growth cut-off point, midway between 1.25 and 2.0%
mancozeb, was calculated and a rate of 1.625% active ingredient per litre of water was
used to decontaminate the fungus-infected D. noxia cultures.
A novel bioassay protocol was developed, employing live host plants for rearing
aphids post inoculation. Using this design against D. noxia, an average LC₅₀ estimate of 85 conidia per mm² for B. bassiana strain GHA was calculated. Control mortality
was restricted to levels below 4%. The data indicated high precision due to an average coefficient of variation for slope of less than 20%, and an average chi-squared value
of 5.46 ± 2.74 (n = 10 assays). The design will accommodate the use of cereal aphid species other than D. noxia, while live host plants will facilitate tritrophic studies on the effect of host-plant resistance on fungus-induced mortality of D. noxia. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.
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Διερεύνηση της επίδρασης του εκχυλίσματος κρόκου στην αύξηση των εντομοπαθογόνων μυκήτων με την μέθοδο των ημιεκλεκτικών υποστρωμάτων και στην αποτελεσματικότητά τους επί των προνυμφών του εντόμου Sesamia nonangrioides / The effect of saffron extract at the growth of entomopathogenic fungi in semi selective substrates and at the efficacy of entomopathogenic fungi on larvae of the insect S. nonangrioidesΜαντζούκας, Σπυρίδων 17 September 2012 (has links)
Η παρούσα μεταπτυχιακή εργασία εκπονήθηκε στο πλαίσιο του Διατμηματικού Προγράμματος Μεταπτυχιακών Σπουδών «Ιατρική Χημεία: Σχεδιασμός και Ανάπτυξη Φαρμακευτικών Προϊόντων». Σκοπός αυτής της έρευνας ήταν η διερεύνηση της επίδραση του εκχυλίσματος κρόκου τόσο στην αύξηση όσο και στην αποτελεσματικότητα των εντομοπαθογόνων μυκήτων επί των προνυμφών του λεπιδοπτέρου Sesamia nonangrioides.
Στην παρούσα μελέτη χρησιμοποιήθηκαν οι εντομοπαθογόνοι μύκητες Beauveria bassiana Balsamo (Vuillemin) (Hypocreales: Cordycipitaceae), Metarhizium robertsii (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) και Isaria fumosorosea (Wize) Brown & Smith (Hypocreales: Clavicipitaceae) από την συλλογή του Μπενακείου Φυτοπαθολογικού Ινστιτούτου των οποίων η διατήρηση έγινε στο εργαστήριο Φυσιολογίας Φυτών του τμήματος Βιολογίας με την μέθοδο των ημιεκλεκτικών υποστρωμάτων (Strasser et al. 1996). Στύλοι του καλλιεργούμενου Crocus sativus εκχυλίστηκαν με διάλυμα 50% v/v μεθανόλης σε νερό (3 mL/50 mg ξηρής δρόγης) για 4 h απουσία φωτός.
Οι παραπάνω εντομοπαθογόνοι μύκητες καλλιεργήθηκαν σε τρυβλία petri με θρεπτικό υλικό Sabouraud Dextrose Agar (S.D.A.) για διάστημα 5 ημερών παρουσία (3,0% v/v) και απουσία (100% S.D.A. αλλά και 98,5% S.D.A. - 1,5% μεθανόλης) εκχυλίσματος. Μετά το πέρας, διαπιστώθηκε ότι η παρουσία της μεθανόλης σε αυτήν τη συγκέντρωση δεν επηρέασε την ανάπτυξη κανενός μύκητα. Περαιτέρω, οι εντομοπαθογόνοι μύκητες B. bassiana και I. fumosorosea δεν επηρεάστηκαν από την
παρουσία του εκχυλίσματος κρόκου στο υπόστρωμα ανάπτυξης, ενώ ο εντομοπαθογόνος μύκητας M. robertsii επηρεάστηκε θετικά (P<0,05, τεστ Bonferoni) από την παρουσία του εκχυλίσματος.
Επιπροσθέτως μελετήθηκε η επίδραση του εκχυλίσματος κρόκου στην αποτελεσματικότητα των εντομοπαθογόνων μυκήτων επί των προνυμφών του εντόμου S. nonangrioides.. Για κάθε εντομοπαθογόνο μύκητα παρασκευάστηκαν τρεις συγκεντρώσεις (106, 107, 108 κονίδια/mL) ενώ η θνησιμότητα των προνυμφών καταγραφόταν καθημερινά για 7 ημέρες. Oι εντομοπαθογόνοι μύκητες προκάλεσαν υψηλά ποσοστά θνησιμότητας στις προνύμφες του εντόμου ιδιαίτερα ο I. fumosorosea (υπόστρωμα μόνο S.D.A) προκάλεσε θνησιμότητα του S. nonangrioides που κυμάνθηκε από 80 έως 93%. Η παρουσία του εκχυλίσματος κρόκου στο υπόστρωμα αύξησε σημαντικά (P<0,05, test Bonferoni) τη θνησιμότητα του εντόμου (80-96%) ένεκα του εντομοπαθογόνου μύκητα M. robertsii. Η σημαντική θετική επίδραση του εκχυλίσματος κρόκου στην αύξηση και την αποτελεσματικότητα του εντομοπαθογόνου μύκητα M. robertsii επί των προνυμφών του S. nonangrioides χρήζουν περαιτέρω διερεύνησης ως προς τους μηχανισμούς με τους οποίους επετεύχθη αλλά και ανοίγουν νέους δρόμους ως προς την ανάπτυξη νέων μεθόδων βιολογικής καλλιέργεια. / This thesis was produced as part of the Interdepartmental Graduate Program entitled “Medicinal Chemistry: Design and Development of Medicinal Products”. The intention of this thesis was to study the effect of saffron extract at the growth of entomopathogenic fungi in semi selective substrates and at the efficacy of entomopathogenic fungi on larvae of the insect S. nonangrioides.
This study used Beauveria bassiana Balsamo (Vuillemin) (Hypocreales: Cordycipitaceae), Metarhizium robertsii (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) and Isaria fumosorosea (Wize) Brown & Smith (Hypocreales: Clavicipitaceae) from the collection of the Benaki Phytopathological Institute and maintain with the selective medium method in laboratory of Plant Physiology at the Department of Biology (Strasser et al. 1996). Saffron (stigmas of Crocus sativus) was extracted with methanol:water 1:1, v/v (3 mL/50 mg dry plant material) for 4 h in the absence of light.
Entomopathogenic fungi were cultured in petri dishes with Sabouraud Dextrose Agar (S.D.A.) for 5 days in the presence (3.0%, v/v) and absence (100% S.D.A. and 98,5% S.D.A. -1,5% methanol) of saffron extract. Methanol in the culture medium did not affect fungal growth at the particular concentration. After the five days, entomopathogenic fungi B. bassiana and I. fumosorosea were not affected by the presence of saffron extract in the growing medium, whereas M. robertsii growth was influenced positively (P<0.05, Bonferoni test) by the presence of saffron extract.
In addition, the effect of saffron extract on the efficacy of entomopathogenic fungi on larvae of S. nonangrioides was studied. For each entomopathogenic fungus three concentrations (106, 107, 108 conidia/mL) were used, while the mortality of larvae was recorded daily for 7 days. Entomopathogenic fungi caused high mortality in larvae of the insect; particularly I. fumosorosea (substrate SDA) induced mortality ranging from 80 to 93%. Saffron in the culture medium of M. robertsii significantly (P<0.05, Bonferoni test) increased insect mortality (80 to 96%). The significant positive effect of saffron in the semi-selective substrate on the growth and effectiveness of M. robertsii on S. nonangrioides larvae demand further investigation of the mechanisms of action and pose new dimension in the use of biological agents.
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Produção e eficiência de isolados de Metarhizium anisopliae (Metsch.) Sorok. no controle da cigarrinha-das-raízes da cana-de-açúcar, Mahanarva fimbriolata (Stal, 1854) (Hemiptera: Cercopidae)Gassen, Mariana Hollanda [UNESP] 25 May 2010 (has links) (PDF)
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gassen_mh_dr_botfca.pdf: 1151986 bytes, checksum: d10ca5877ac7bff31ebce19ef7356faf (MD5) / A cana-de-açúcar colhida sem queima é uma realidade em todo o Estado de São Paulo e os ataques da cigarrinha-da-raiz da cana estão cada vez mais freqüentes e intensos. O controle biológico desta praga com o fungo Metarhizium anisopliae também vem se desenvolvendo e adquirindo relevada importância. Com isso, este trabalho foi conduzido com os seguintes objetivos: avaliar a produção de conídios de diferentes isolados para o controle da cigarrinha-das-raízes, a partir de dois tipos de arroz; avaliar a eficiência dos isolados selecionados como mais produtivos em populações naturais de Mahanarva fimbriolata, na cultura da cana-de-açúcar colhida mecanicamente e; verificar o manejo da população de M. fimbriolata em áreas de cana-de-açúcar colhidas sem queima da palha, observando a influência da umidade sobre sua ocorrência. Foram avaliados 14 isolados, os quais foram produzidos em arroz tipo 1 e arroz parboilizado, em sacos de polipropileno, incubados em sala climatizada para desenvolvimento do fungo. Avaliou-se a concentração e viabilidade de cada isolado para os dois tipos de arroz. Os isolados que apresentaram maior produtividade foram aplicados em campo para avaliar a patogenicidade dos mesmos à cigarrinha-das-raízes, sendo eles: ESALQ 1037, IBCB 425, IBCB 353, IBCB 410, F 99 e IBCB 333. Foram pulverizados 2 kg/ha de arroz+fungo, contendo 1,0 x 1012 conídios/ha, além do tratamento com o inseticida tiametoxam 250 WG e a testemunha, sem aplicação. As avaliações foram realizadas aos 15, 30, 60, 90 e 120 dias após a aplicação (DAA), observando-se o número de ninfas e adultos de M. fimbriolata vivos, mortos, parasitados ou não, em cada parcela. A partir dos resultados, foi possível observar que os isolados IBCB 410 e F 99 causaram, respectivamente, mortalidades de 66,67 e 33,33% para ninfas, aos 15 DAA. Após 30 DAA, os isolados IBCB 425, IBCB 353 e IBCB 333... / The sugar cane is harvested without burning a reality throughout the state of Sao Paulo and the attacks of the leafhopper-root cane are increasingly frequent and intense. Biological control this pest with the Metarhizium anisopliae also has been developing and acquiring increasing importance. Therefore, this work was conducted to evaluate the production of conidial selected for the control of root speatlebug in two types of rice, evaluate the efficiency of the isolates selected as the most productive in natural populations of M. fimbriolata, the culture of cane sugar harvested mechanically, monitor the population of M. fimbriolata in areas of sugarcane harvested without burning the straw, and the influence of temperature and humidity on its occurrence. We evaluated 14 isolates, which were produced in rice type 1 and parboiled rice in polypropylene bags, incubated in a room for fungal growth and were evaluated the concentration and viability of each isolate for both types of rice. The isolates that had higher yields were applied in the field to assess the pathogenicity of the same root speatlebug, namely: ESALQ 1037, IBCB 425, IBCB 353, IBCB 410, F 99 and IBCB 333. Were sprayed 2 kg / ha of rice + fungus, containing 1,0 x 1012 conidia / ha, in addition to treatment with the insecticide tiametoxam 250 WG and the control. Evaluations were performed at 15, 30, 60, 90 and 120 days after the application, noting the number of nymphs and adults of M. fimbriolata alive in each plot, and the number of nymphs and adults dead, infected and non-parasitized. From the results, it was observed that isolates IBCB 410 and F 99 caused mortality to nymphs of 66.67 and 33.33%, respectively, at 15 days after application. After 30 days of spraying, the isolates IBCB 425, IBCB 353 and IBCB 333 had efficiencies... (Complete abstract click electronic access below)
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Potvrzení výskytu \kur{Beauveria caledonica} v NP Šumava pomocí metod molekulárních markerů / Confirmation of \kur{Beauveria caledonica} occurence in Šumava National park by molecular markersBINDER, Richard January 2015 (has links)
Biological plant protection against insect pests is an important alternative to chemical protection. One of the most important group used in the biological plant protection against insect pests are the entomopathogenic fungi. Entomopathogenic fungi are microscopic fungi that are able to induce a primary disease to insect pests. It is a very heterogeneous group of species. Worldwide there were isolated and described more than 750 species of entomopathogenic fungi. Genus Beauveria is considered one of the most important genera of entomopathogenic fungi. In the Czech Republic there has been confirmed species B. bassiana, B. brongniartii and now, on the basis of this work, B. caledonica. This study is aimed to confirm the occurrence of B. caledonica in National Park Šumava. To confirm this occurrence, I used analyzes based on the methods of molecular markers. Molecular markers are an indispensable part of science in the field of mycology, for example the strain characterization, population genetics, detection and identification of fungi, phylogenetic studies and evolutionary biology. For this study there were used sequence analysis of ITS, EF1- and LSU regions. The output data of these analyzes were used to create phylogenetic trees. The result of my thesis is taxonomical classification of studied isolates on species level.
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Účinnost entomopatogenní houby \kur{Metarhizium anisopliae} na vybrané druhy hostitelů / Efficacy of entomopathogenic fungus \kur{Metarhizium anisopliae} against different hostsKONOPICKÁ, Jana January 2016 (has links)
Entomopathogenic fungus \kur{Metarhizium anisopliae} is one of the most common species used in biological control against pests. The thesis is analyzing effectiveness of original strains and continuously passaged strains of \kur{M. anisopliae} through nutrient substrates and different developmental stages mealworm \kur{(Tenebrio molitor)}. For original and continuously passaged strains were also evaluated the growth and spore production at different temperatures cultivation. In this thesis was investigated the efficacy of the original strains of \kur{M. anisopliae} on selected economically important pests. Strains were tested on populations of adults Pollen beetles \kur{(Meligethes aeneus)} and Cabbage seedpod weevil \kur{(Ceutorhynchus obstrictus)} and the eggs of Colorado potato beetle \kur{(Leptinotarsa decemlineata)} in laboratory conditions. Other entomopathogenic fungi were tested on the eggs of Colorado potato beetle eggs.
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Kompatibilita vybraných druhů entomopatogenních hub s parazitoidem Encarsia formosa / Compatibility of different entomopathogenic fungi with parasitoid Encarsia formosaŠTĚPÁNOVÁ, Kristýna January 2007 (has links)
This M.Sc. thesis is aimed to describe level of the compatibility between various strains of several entomopathogenic fungi with parasitoid wasp Encarsia formosa. From many species of entomopathogenic fungi Aschersonia aleyrodis, Beauveria bassiana, B, brongniartii, Lecanicillium lecanii, Metarhizium anisopliae and Paecilomyces fumosoroseus were the species which were tested in experiments. It was found, that A. aleyrodis is very selective, because it infects only unparasitized nymphs of greenhouse whitefly Trialeurodes vaporariorum. All other strains of tested fungi were much less selective, however their efficacy always increased total efficacy when compared with the efficacy of parasitoid alone. It was concluded, that fungi A. aleyrodis, L. lecanii and P. fumosoroseus posse{\crq}s big potential for construction of IPM programs.
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Možnosti techniky AFLP ve studiu genetické struktury populací Beauveria bassiana / Possibilities of AFLP technique in study of \kur{Beauveria bassiana} genetic structureKOTLANOVÁ, Kristina January 2010 (has links)
Beauveria bassiana is widely used in biological control against the economically significant pests. Detection of morphological and genetic polymorphism among single species and strains in natural environment is important to study of the distribution and the effects in the ecosystem. The aim of this study was to determine the links of "local strains" with ecological aspects of biological control in protected zone of National park and assess the polymorphism of the population monitored in NP Šumava and exotic strains using molecular markers. There were analyzed 39 strains collected in the NP Šumava and the Krkonoše National Park in the Czech Republic and 11 strains from different countries and areas. The polymorphism of these strains was evaluated by different methods based on DNA analysis. In this study, the genetic variability is evaluated by AFLP markers. The results reveal that population from NP Šumava is very closed and the "local strains" can be very well characterized thanks these methods and compared with other strains from different parts of the Czech Republic and other countries. Thanks to these screening analyses, the strain Bba I101was determined for the preparation which will be used for bark beetle (Ips typographus) control in the National Park Šumava in the Czech Republic. This study was supported by grants GACR 521/08/H042, MSM 60076658-06, MZP SP/2d1/41/08.
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Produção, persistência e eficiência da pulverização eletrostática de Isaria javanica no manejo de Bemisia tabaciFigueiredo, Lara Leal 28 May 2018 (has links)
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Previous issue date: 2018-05-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The whitefly, Bemisia tabaci (Gennadius, 1889), is an insect that has great importance
in world agriculture. It adapts easily to diverse cultures and environments, thus, making it difficult
to handle. The use of the entomopathogenic fungus Isaria javanica is considered a promising tactic
for the management of whitefly. The objectives of this work were to select isolates of I. javanica
with higher conidia production in solid medium; to evaluate the efficiency of different methods of
entomopathogenic fungus application on whitefly nymphs; quantify the number of conidia
deposited on the abaxial face of the bean leaves and evaluate the persistence of the conidia in the
environment. To evaluate the production of conidia, three isolates of I. javanica were used and
placed in Erlenmeyer containing 200 grams of parboiled rice. The isolate CNPAF 14 presented the
highest yield of conidia (1.20 x 1010 conidia / gram of rice). In the evaluation of the efficiency of
different spraying methods, the electrostatic sprayer, CO2 and Air brsuh were used. Bean plants
were grown in pots in the greenhouse and infested with white-fly adults for nymphs. Bean plants
with 2nd instar nymphs were sprayed with Tween 80® solution [0.05%], suspension of fungus I.
javanica [1x107 conidia.mL -1 ] and spiromesifene 0.5 L / ha. The methods of electrostatic spraying
and CO2 did not show differences in the mortality of whitefly nymphs. To evaluate the deposition
and the persistence of conidia was used the isolate CNPAF 14 [5x106 conidia.mL -1 ]. Suspension
was applied with the electrostatic sprayer and CO2 in the potted bean plants in the greenhouse. The
spraying methods did not increase the amount of conidia deposited on the abaxial face of the bean
leaves and did not interfere in the persistence. Future studies should be conducted to enable
commercial production of the entomopathogenic fungus I. javanica to assist in the management of
B. tabaci. / A mosca-branca, Bemisia tabaci (Gennadius, 1889), é um inseto que tem uma grande
importância na agricultura mundial. Adapta-se facilmente a diversas culturas e ambientes, assim,
dificultando o seu manejo. O uso do fungo entomopatogênico Isaria javanica é considerado uma
tática promissora para o manejo de mosca-branca. Os objetivos deste trabalho foram selecionar
isolados de I. javanica com maior produção de conídios em meio sólido; avaliar a eficiência de
diferentes métodos de aplicações do fungo entomopatogênico sobre ninfas de mosca-branca;quantificar o número de conídios depositados na face abaxial das folhas de feijoeiro e avaliar a
persistência dos conídios no ambiente. Para avaliar a produção de conídios, foram utilizados três
isolados de I. javanica e colocados em Erlenmeyer contendo 200 gramas de arroz parboilizado. O
isolada CNPAF 14 apresentou o maior rendimento de conídios (1,20 x 10 10 conídios/grama de
arroz). Na avaliação da eficiência de diferentes métodos de pulverização foi utilizado o
pulverizador eletrostático, CO2 e Air brsuh. Plantas de feijão foram cultivadas em vasos na casa de
vegetação e infestadas com adultos de mosca-branca para a obtenção de ninfas. As plantas de
feijão com ninfas de 2o instar foram pulverizadas com solução de Tween 80® [0,05%], suspensão
do fungo I. javanica [1x10 7 conídios.mL -1 ] e espiromesifeno 0,5 L/ ha. Os métodos de pulverização
eletrostático e CO2 não apresentaram diferenças na mortalidade de ninfas de mosca-branca. Para
avaliar a deposição e a persistência de conídios foi utilizado o isolado CNPAF 14 [5x10 6
conídios.mL -1 ]. A suspenção foi aplicada com o pulverizador eletrostático e CO2 nas plantas de
feijão em vasos na casa de vegetação. Os métodos de pulverização não incrementar na quantidade
de conídios depositados na face abaxial das folhas de feijoeiro e não interferiram na persistência.
Estudos futuros deverão ser conduzidos para viabilizar a produção comercial do fungo
entomopatogênico I. javanica para auxiliar no manejo de B. tabaci.
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Controle de Tetranychus urticae Koch com fungos entomopatogênicos. / Control of Tetranychus urticae Koch with entomopathogenic fungi.Marco Antonio Tamai 21 March 2002 (has links)
Dentre 45 isolados de Hyphomycetes testados, oito de Beauveria bassiana e quatro de Metarhizium anisopliae causaram em Tetranychus urticae, mortalidades superiores a 80 e 90%, respectivamente, cinco dias após a inoculação na concentração de 5x10 7 conídios/mL. Hirsutella sp. atingiu 73% de mortalidade na concentração de 1,7x10 7 conídios/mL. Entre 80 a 100% dos cadáveres de ácaros colonizados pelos isolados de B. bassiana e M. anisopliae apresentavam, internamente, cristais de cálcio. Conídio aéreo, blastósporo e célula de levedura de cinco isolados B. bassiana foram patogênicos a esta praga. Diferenças significativas (P ³ 0,05) para CL50 e coeficiente angular entre os isolados e entre as estruturas infectivas foram observadas. Os valores da CL50 variaram de 4,95x10 6 a 8,21x10 7 estruturas infectivas/mL. Não houve diferença significativa entre as estruturas infectivas para os dois parâmetros avaliados, contudo, houve diferenças significativas para a CL50 entre as estruturas infectivas em um mesmo isolado de B. bassiana. Três formulações de fungicidas, 24 de inseticidas e/ou acaricidas foram compatíveis com B. bassiana, sendo formulados com as seguintes moléculas: propamocarb hidrocloreto, enxofre, abamectin, acefato, acetamiprid, betacyflutrin, bifentrina, ciromazina, deltametrina, diafentiuron, diflubenzuron, dimetoato, fenpropatrina, fenpyroximate, fenvalerate, imidacloprid, metamidofós, propargite, tebufenozide e triclorfon. Houve grande variação na toxicidade dos produtos dentro de cada grupo químico e produtos formulados com a mesma molécula química. B. bassiana foi eficiente no controle de T. urticae em crisântemo (Dendranthema grandiflora) cultivado em estufa, quando pulverizado na concentração de 2x10 8 conídios/mL. O controle microbiano foi superior ao proporcionado pelo controle químico utilizado na propriedade agrícola. Efetuando-se quatro pulverizações do fungo em um período de 14 dias, a densidade reduziu de 1,8 para 0,1 ácaro/folha. Na cultura do morango (Fragaria spp.) a eficiência de B. bassiana foi inferior ao crisântemo, com densidade média de ácaros ao longo de 21 dias de avaliação para as concentrações 1x10 8 e 5x10 7 conídios/mL de 13 ácaros/folíolo, contra 43 ácaros/folíolo nas parcelas não tratadas. As variedades de morango Campinas e Princesa Isabel foram as que apresentaram as menores densidades do ácaro, contudo, não houve evidência de que estas variedades interferiram na eficiência de controle da praga por B. bassiana. Assim, M. anisopliae, B. bassiana e Hirsutella sp. foram os fungos mais promissores para serem formulados como micoacaricidas para o controle de T. urticae. / Among 45 isolates of hyphomycetes tested against Tetranychus urticae, 8 Beauveria bassiana and 4 Metarhizium anisopliae isolates caused mortality > 80 and 90%, respectively, 5 days after inoculation with 5x10 7 conidia/mL. Hirsutella sp. caused 73% mortality at a concentration of 1.7x10 7 conidia/mL. Eighty to 100% of cadavers infected by B. bassiana or M. anisopliae isolates had calcium crystals inside their bodies. Conidia, blastospores and yeastlike cells of five B. bassiana isolates were pathogenic against this pest. Significant differences (P ³ 0.05) were observed among the LC50's and slopes of dose-mortality lines for the different isolates and infective structures. LC50 values ranged from 4.95x10 6 to 8.21x10 7 cells/mL. There were no significant differences among the infective structures in the two tested variables. However, there were significant differences among the LC50's with different infective structures within the same B. bassiana isolate. Three fungicide formulations and 24 insecticides and/or mitecides were compatible with B. bassiana including those with the following active ingredients: propamocarb hydrochloride, sulphur, abamectin, acephate,acetamiprid, betacyfluthrin, bifenthrin, cyromazine, deltamethrin, diafentiuron, diflubenzuron, dimethoate, fenpropathrin, fenpyroximate, fenvalerate, imidacloprid, methamidophos, propargite, tebufenozide and trichlorfon. There was large variability in the toxicity of products withing a chemical group and products containing the same active ingredient. B. bassiana was an efficient T. urticae mite control in chrysanthemum (Dendranthema grandiflora), when applied at a concentration of 2x10 8 conidia/mL. Microbial control was better than that provided by chemical pesticides normally used in the greenhouses. With four fungal sprays within 14 days, the mite density was reduced from 1.8 to 0.1 mite/leaf. In strawberry (Fragaria sp.), T. urticae control was lower than in chrysanthemum, with mean density of mites for 21 days after application of 1x10 8 or 5x10 7 conidia/mL at 13 mites/leaflet, compared to 43 mites/leaflet in control plots. The strawberry varieties 'Campinas' and 'Princesa Isabel' had the lowest mite densities, however, these varieties did not affect the efficacy of mite control by B. bassiana. Thus, M. anisopliae, B. bassiana and Hirsutella sp. were the most promissing fungi to be formulated as mycomiticides for T. urticae control.
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Utilização de fungos entomopatogênicos para o controle de Orthezia praelonga (Sternorryncha: Ortheziidae). / Utilization of entomopathogenic fungi for the control of Orthezia praelonga (sternorryncha: ortheziidae).Marcelo de Oliveira Garcia 14 May 2004 (has links)
Avaliou-se a patogenicidade de 50 isolados de 8 espécies de fungos entomopatogênicos e o produto comercial Boverilâ, formulado com isolado ESALQ-447 de B. bassiana para ninfas de 2 e 3 ínstar de Orthezia praelonga. Em outro experimento avalio-se a produção do isolado selecionado em dois sistemas de produção. Nos ensaios de seleção foram usados tubetes de citros infestados pela cochonilha. O patógeno foi inoculado pulverizando-se 5mL de suspensão conidial por muda, na concentração de 1 x 108 conídios/mL, utilizando-se um pulverizador com pressão constante de 0,5 libras/segundo. As mudas foram mantidas em estufas B.O.D. (25±0,5°C, 70±10% UR e 12 horas de fotofase). Dos isolados testados, 30 foram patogênicos para cochonilha causando mortalidade corrigida que variaram de 1,0 % a 46,6%, sendo que os melhores resultados foram obtidos com os isolados ESALQ-972 e ESALQ-1300 de V. lecanii que proporcionaram 46,6 % e 40,5%, respectivamente, após 12 dias da aplicação. Para os testes de produção foram utilizados dois métodos. O método da bandeja no qual se utilizou o arroz pré-cozido, esterilizado e inoculado com fungo em bandejas de plástico, com ciclo de produção de 15 dias. No outro método, utilizou-se de uma caixa plástica, contendo uma lâmina dágua no fundo do recipiente e um sistema de aeração constante para fornecer pressão positiva e manter o ambiente com umidade acima de 90 %. O isolado testado foi o ESALQ-972, e os métodos da bandeja e da caixa proporcionaram produção de 1,8 x 109 e 1,0 x 109 conídios/grama de arroz, respectivamente. / The pathogenicity was evaluated for 50 isolates of 8 species of entomopathogenic fungi and the commercial product Boverilâ, composed by the isolate ESALQ-447 of B. bassiana for nymphs of 2 and 3 instar of Orthezia praelonga. In another experiment the production of the isolated was selected in two production systems. In the selection tests, seedlings of citrus infested by the scale were used. The pathogen was inoculated pulverizing 5 ml of conidial suspension by seedlings, with a concentration of 1 x 108 conidia/ml, using a pulverizer with constant pressure of 0.5 lbs/second. The seedlings were kept in B.O.D. (25±0,5°C, 70±10% UR and 12 hours of photophase). From the isolates tested, 30 were pathogenic to the scale causing corrected mortality that varied from 1.0% to 46.6%, while the best results were obtained with the isolates ESALQ-972 and ESALQ-1300 of V. lecanii which generated 46.6% e 40.5%, respectively, after 12 days of aplication. For the production tests two methods were utilized. The tray method, which used the pre-cocked rice, sterilized and inoculated with fungus in plastic trays, with a production cicle of 15 days. In the other method, a plastic box was used, containing a water blade in the bottom and a constant ventilation system to provide positive pressure and keep the environment with humidity above 90%. The isolate tested was the ESALQ-972, resulting that the tray and the plastic box methods produced 1.88 x 109 and 1.0 x 109 conidia/gram of rice, respectively.
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