993 resultados para Natural Biological Control


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The mite family Stigmaeidae (Acari:Prostigmata) is of considerable importance in biological control, but its genera are often poorly defined and have never been subjected to cladistic analysis. Herein, we report the stigmaeid genus Ledermuelleriopsis Willmann from Australia for the first time, present a preliminary phylogenetic analysis that demonstrates that Eustigmaeus Berlese and Ledermuelleriopsis Willman are distinct, review the genus at the world level, and provide diagnostic characters of the adult females for each of the 21 known species. We also catalogue habitats, distributions and localities of holotypes. Four new species from Australia are described and illustrated: L. parvilla, sp. nov. from old dune sand, L. barbellata, sp. nov. from wet-sandy heath litter, and L. pustulosa, sp. nov. and L. claviseta, sp. nov. from dry eucalypt forest litter. A key to adult females of all known Ledermuelleriopsis species is provided. The Australian species and L. incisa Wood from New Zealand can be separated from all other members of the genus by a synapomorphy: the reduction of the number of setae on the aggenital shield to one pair. Results of a preliminary morphological cladistic analysis for those stigmaeid genera in which the larvae and adults of both sexes are known, indicate that Ledermuelleriopsis is basal to a clade containing Cheylostigmaeus Willman and Eustigmaeus.

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Foi feito um levantamento da fauna de Hymenoptera parasitóides em um transecto eucalipto/vegetação nativa/eucalipto, em Ipaba, Minas Gerais, no período de março de 1997 a março de 1998, com armadilhas Malaise. Foram coletados indivíduos de nove superfamílias (Ceraphronoidea, Chalcidoidea, Chrysidoidea, Cynipoidea, Evanioidea, Ichneumonoidea, Proctotrupoidea, Platygastroidea e Vespoidea), distribuídos em 26 famílias.

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It was studied the parasitism capacity of Trichogramma acacioi on Anagasta kuehniella and Sitotroga cerealella eggs at different temperatures (15, 20, 25, 30 and 35 ± 1°C). The parasitism of T. acacioi varied with temperature and host. The highest parasitism (³80%) were observed during the first days after emergence in both hosts, at all tested temperatures. The accumulated parasitism varied with both host and temperature, being higher on A. kuehniella at 20°C, what shows good parasitoid species adaptation to this temperature. Thus, we conclude that the best host and best temperature to be used at mass-rearing of T. acacioi is A. kuehniella and 20ºC, respectively. Moreover, this Trichogramma species has great potential to be used in field releases at regions where average temperature is around 20ºC.

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A broca-pequena-do-fruto, Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) é uma praga de grande importância na cultura do tomateiro. Desta forma, métodos de manejo que auxiliem no controle dessa praga e que reduzam a aplicação de agrotóxicos devem ser estudados. O objetivo do presente trabalho foi avaliar métodos alternativos de manejo da broca-pequena-do-fruto, como: o controle biológico, através da utilização de parasitoides do gênero Trichogramma e nematoides entompatogênicos (Heterorhabditis indica e Sterneneima carpocapsae); o controle físico, por meio do ensacamento de cachos de tomate com o tecido-não-tecido (TNT); e o controle químico através do estudo da atividade inseticida de plantas como a pimenta, o fumo, o alho e a mamona nas fases embrionárias, larval, pupal e adulta. Desta forma, por meio das análises foi possível verificar que a espécie e/ou linhagem de Trichogramma que mais se destacou foi T. galloi (Tg1) com características biológicas favoráveis ao manejo de N. elegantalis. Para os nematoides entomopatogênicos, S. carpocapsae, foi o mais efetivo, causando uma mortalidade de 82,93% a uma concentração de 65 juvenis infectivos por pré-pupa da broca-pequena-do-fruto. Através do ensacamento dos frutos, foi possível verificar a redução na oviposição da praga em frutos do tomateiro para quase zero com sacolas de TNT com fundo fechado, não ocorrendo alteração no peso, pH e graus brix do fruto, enquanto que no controle químico através de inseticidas botânicos foi possível verificar o destaque do extrato aquoso de fumo, reduzindo a oviposição, entrada e saída das lagartas nos frutos; causando mortalidade na fase embrionária, lagarta, pré-pupa e pupa da broca-pequena-do-fruto.

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A lagarta Duponchelia fovealis Zeller (Lepidoptera: Crambidae) foi relatada em plantios comerciais do morangueiro no estado do Espírito Santo ocasionando grandes problemas à cultura. Porém, por ser uma praga recente, não há registro de produtos para o seu controle. A cada dia aumenta a demanda por alimentos e outros produtos livres de resíduos, além da necessidade de uma agricultura mais desenvolvida e sustentável. Pesquisas com agentes de controle biológico e extratos vegetais surgem como alternativa para o manejo desse inseto-praga. Este trabalho teve como objetivo avaliar a eficiência de formulados comerciais à base de Bacillus thuringiensis e a atividade do uso dos extratos aquosos de alho e fumo, visando sua adoção como métodos alternativos de controle de D. fovealis. Nos bioensaios para avaliar a patogenicidade e virulência de duas formulações comerciais à base de B. thuringiensis, Agree® e Dipel WP®, sobre a dieta artificial adaptada à base de farelo de soja, germe de trigo e açúcar, proposta por King e Hartley (1985) para Diatraea saccharalis (Lepidoptera: Crambidae), foram inoculados 70 μL de cada formulado comercial, na concentração 1 x 108 esporos·mL-1. Em seguida, avaliou-se a virulência dos respectivos formulados, isso através da estimativa da concentração letal (CL50) para o estádio de maior suscetibilidade. Em virtude dos resultados encontrados, observou-se que o estágio 1 de desenvolvimento apresentou 95,88% e 86,76% de mortalidades para os produtos Agree® e Dipel WP®, respectivamente, demonstrando patogenicidade e virulência à D. fovealis. No bioensaio para avaliar a atividade dos extratos aquosos de alho e fumo, estes foram aplicados na concentração 10% (m/v). Todos os tratamentos foram pulverizados com Torre de Potter, calibrada a pressão de 15 lb/pol². Posteriormente estimou-se a concentração letal (CL50) do extrato aquoso de fumo, o qual apresentou 95% de mortalidade no teste de suscetibilidade. Desta forma, com os resultados obtidos na presente pesquisa, concluiu-se que a utilização de formulados comerciais à base de B. thuringiensis e extrato de fumo podem ser uma alternativa no manejo fitossanitário de D. fovealis.

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This study evaluated the effects on the development and predatory capacity of Podisus nigrispinus fed on Spodoptera frugiperda that have ingested different concentrations of neem oil. The predatory capacity of Podisus nigrispinus was assessed, separating nymphs (fourth instar) and adults (males and females). The treatments consisted of S. frugiperda larvae reared in neem oil aqueous solutions (0.077, 0.359 and 0.599%), deltamethrin EC 25 (0.100%) and control arranged in a completely randomized design, with ten replicates. Insects were offered three larval densities (one, three and six), in the third or fourth instars. The predated larvae were examined at 24 and 48 hours after the beginning of the experiment. Biological parameters of Podisus nigrispinus were evaluated in groups of ten second-instar nymphs transferred to pots, in five replicates. Insects were offered 2-6 third and/or fourth-instar larvae reared in the same neem oil concentrations in a completely randomized design. The following parameters were evaluated: duration of each nymph stage (days), nymph mortality (%), weight of fifth-instar nymphs (mg), sex ratio, weight of males and females (mg) and longevity of unfed adults (days). The predatory capacity of nymphs and adults of Podisus nigrispinus was influenced by the neem oil at the concentrations of 0.359% and 0.599% in the highest density. The concentration of 0.359% lengthened the nymphal stage and the concentration of 0.599% reduced the weight of males.

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Dissertação de Mestrado, Biotecnologia em Controlo Biológico, 18 de Dezembro de 2013, Universidade dos Açores.

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Tese de Doutoramento, Biologia (Biologia Celular e Molecular), 18 de Novembro de 2013, Universidade dos Açores.

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Presented thesis at Faculdade de Ciências e Tecnologias, Universidade de Lisboa, to obtain the Master Degree in Conservation and Restoration of Textiles

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In this present study, preliminary data was obtained regarding the mortality rate of the Amazonian anophelines, Anopheles nuneztovari, Anopheles darlingi and Anopheles braziliensis when subjected to treatment with Bacillus sphaericus strain 2362, the WHO standard strain. Initially, experiments were conducted to test the mortality rate of the three species of anopheline larvae. The third larval instar of An. nuneztovari and the second and third larval instars of An. darlingi proved to be the least susceptible. In other experiments, the same three mosquito species were tested with the standard strain 2362, An. nuneztovari was the least susceptible to this insect pathogen, while An. braziliensis was the most susceptible. This latter species showed a difference in the level of LC50 concentration, when compared to the former, of 2.4, 2.5 and 1.8 in readings taken 24, 48 and 72 hours after exposure to the bacillus.

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Resistance of the dengue vector to temephos stimulated its substitution for Bacillus thuringiensis var. israelensis (Bti) since 2001 in Brazil. The persistence of the two Bti formulations employed at that time by the Health Ministry, Vectobac G and Aquabac G, was assayed under laboratory and outdoor conditions. Both formulations were tested at 0.2 g/10 liters of water, the same concentration applied in the field for vector control. The tests were done against Ae. aegypti third instar larvae (Rockefeller strain). In the laboratory, Vectobac G and Aquabac G caused at least 95% mortality until 101 and 45 days after treatment, respectively. In the outdoor assays, test containers of different materials were treated with either formulation and placed in a shaded area. Larvae were introduced each 3-6 days and mortality was recorded 24 and 48 hours later. In the first set of assays, performed in June 2001, mortality levels of 70% or more were attained for 2-5 weeks for both formulations in all containers. The exception was for the iron one that rusted, resulting in low mortality after seven days. In the second set of assays (August 2001), 70% mortality was attained for just 1-2 weeks for all the containers and both formulations.

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We present the fi rst review of Hymenoptera alien to Europe. Our study revealed that nearly 300 species of Hymenoptera belonging to 30 families have been introduced to Europe. In terms of alien species diversity within invertebrate orders, this result ranks Hymenoptera third following Coleoptera and Hemiptera. Two third of alien Hymenoptera are parasitoids or hyperparasitoids that were mostly introduced for biological control purposes. Only 35 phytophagous species, 47 predator species and 3 species of pollinators have been introduced. Six families of wasps (Aphelinidae, Encyrtidae, Eulophidae, Braconidae, Torymidae, Pteromalidae) represent together with ants (Formicidae) about 80% of the alien Hymenoptera introduced to Europe. Th e three most diverse families are Aphelinidae (60 species representing 32% of the Aphelinid European fauna), Encyrtidae (55) and Formicidae (42) while the Chalcidoidea together represents 2/3 of the total Hymenoptera species introduced to Europe. Th e fi rst two families are associated with mealybugs, a group that also included numerous aliens to Europe. In addition, they are numerous cases of Hymenoptera introduced from one part of Europe to another, especially from continental Europe to British Islands. Th ese introductions mostly concerned phytophagous or gall- maker species (76 %), less frequently parasitoids. Th e number of new records of alien Hymenoptera per year has shown an exponential increase during the last 200 years. Th e number of alien species introduced by year reached a maximum of 5 species per year between 1975 and 2000. North America provided the greatest part of the hymenopteran species alien to Europe (96 species, 35.3%), followed by Asia (84 species, 30.9%) and Africa (49 species, 18%). Th ree Mediterranean countries (only continental parts) hosted the largest number of alien Hymenoptera: Italy (144 spp.), France (111 spp.) and Spain (90 spp.) but no correlation was found with the area of countries. Intentional introduction, mostly for biological control, has been the main pathway of introduction for Hymenoptera. Consequently, the most invaded habitats are agricultural and horticultural as well as greenhouses. To the contrary, Hymenoptera alien in Europe are mostly associated with woodland and forest habitats. Ecological and economic impacts of alien Hymenoptera have been poorly studied. Ants have probably displaced native species and this is also true for introduced parasitoids that are suspected to displace native parasitoids by competition, but reliable examples are still scarce. Th e cost of these impacts has never been estimated.

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AbstractINTRODUCTION: This study evaluated whether different strains of Brevibacillus laterosporus could be used to control larvae of the blowfly Chrysomya megacephala , a pest that affects both human and animal health.METHODS:Mortality rates were recorded after 1-mL suspensions of sporulated cells of 14 different strains of B. laterosporus were added to 2.5g of premixed diet consisting of rotting ground beef fed to first instar larvae of C. megacephala . All bioassays were performed using 10 larvae per strain, with a minimum of three replicates for each bioassay. Larval mortality was recorded daily up to seven days.RESULTS:Strains Bon 707, IGM 16-92, and Shi 3 showed the highest toxicity toward the larvae producing 70.5%, 64.5%, and 51.6% of larval mortality, respectively, which was significantly higher than that in the control group (p < 0.05). In contrast, strains NRS 1642, NRS 661, NRS 590 BL 856, NRS 342, ATCC 6457, Bon 712, and NRS 1247 showed limited or no pathogenic activity against the target larvae.CONCLUSIONS:Our preliminary data indicated that B. laterosporus could be used to develop bioinsecticides against C. megacephala .

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Secondary metabolites from plants are important sources of high-value chemicals, many of them being pharmacologically active. These metabolites are commonly isolated through inefficient extractions from natural biological sources and are often difficult to synthesize chemically. Therefore, their production using engineered organisms has lately attracted an increased attention. Curcuminoids, an example of such metabolites, are produced in Curcuma longa and exhibit anti-cancer and anti-inflammatory activities. Herein we report the construction of an artificial biosynthetic pathway for the curcuminoids production in Escherichia coli. Different 4-coumaroyl-CoA ligases (4CL) and polyketide synthases (diketide-CoA synthase (DCS), curcumin synthase (CURS) and curcuminoid synthase) were tested. The highest curcumin production (70 mg/L) was obtained by feeding ferulic acid and with the Arabidopsis thaliana 4CL1 and C. longa DCS and CURS enzymes. Other curcuminoids (bisdemethoxy- and demethoxycurcumin) were also produced by feeding coumaric acid or a mixture of coumaric and ferulic acids, respectively. Curcuminoids, including curcumin, were also produced from tyrosine through the caffeic acid pathway. To produce caffeic acid, tyrosine ammonia lyase and 4-coumarate 3-hydroxylase were used. Caffeoyl-CoA O-methyltransferase was used to convert caffeoyl-CoA to feruloyl-CoA. This pathway represents an improvement of the curcuminoids heterologous production. The construction of this pathway in another model organism is being considered, as well as the introduction of alternative enzymes.