Levantamento de Bacillus thuringiensis no Brasil: Distribuição Geográfica e Atividade Inseticida ContraSpodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)RESUMO -O total de 3408 cepas de Bacillus thuringiensis foi isolado de 1448 amostras de solo provenientes de 10 estados, em quatro regiões brasileiras, abrangendo 96 municípios. As cepas foram avaliadas contra lagartas de Spodoptera frugiperda (J. E. Smith) sendo que apenas 62% mataram entre 81% e 100%, e 1758 não causaram mortalidade. O Sul destacou-se com 16,6% de cepas eficientes (mortalidade>75%) do total obtido por região, seguido das regiões Centro Oeste (3,1%), Sudeste (1,1%), e Nordeste (0,4%). PALAVRAS-CHAVE: Insecta, bactéria, isolado nativo, controle biológico, patologiaABSTRACT -A total of 3408 strains of Bacillus thuringiensis were collected from 1448 soil samples in 10 Brazilian states, four different geographical regions, covering 96 counties. These strains were evaluated against Spodoptera frugiperda (J.E. Smith) larvae. Only 62% killed between 81% and 100% and 1758 caused no mortality. Highest proportion of efficient strains (larval mortality above 75%) was found from the total isolated per region in the South Region (16.6%), followed by Western Central (3.1%), Southeast (1.1%) and Northeast Region (0.4%).

Novel vegetative insecticidal proteins (Vips) identified in the supernatant of Bacillus thuringiensis (B.t.) cultures have shown to provide adequate control over a wide spectrum of economically important crop pests. To evaluate the potential applicability of these proteins against fall armyworm (Spodoptera frugiperda Smith) larvae, the most important insect pest for tropical maize, the characteristics and mortality effects of culture supernatants from five B.t. strains were investigated. Striking differences among strains were detected, not only in terms of efficiency in killing the insect, but also regarding to mortality effects of heated and non-heated supernatants, which were used to distinguish the heat-sensitive protein-derived insecticidal fraction from a thermostable one, with a non-protein nature (b-exotoxinas). The qualitative, quantitative and temporal patterns of total protein secretion in the medium (supernatant) were assessed through spectrophotometry and polyacrylamide gel electrophoresis. The strains showed remarkably distinct rates of growth and timing for protein secretion relative to cell density in culture. Moreover, the electrophoretic-banding patterns also varied in a strain-specific manner, both in denaturing and non denaturing conditions. Polypeptides displaying a molecular weight that is very close to the expected for previously identified Vip3A proteins were found for the strains with high supernatant-mortality ratios. The data suggest the feasibility and usefulness of searching for protein-derived (Vip-like) insecticidal fractions in B.t. supernatants as a mean of developing especific and efficient alternatives of biological control to be employed in integrated pest management programs of S. frugiperda in tropical maize.

Chromobacterium violaceum is a free-living Gram-negative bacterium found in soil and aquatic habitats; abundantly present in the Brazilian Amazon, it is an important example of exploitable microbial diversity of the tropics. In this study, 24 strains from the Brazilian Amazon and ATCC 12472(T) were investigated for biocontrol potential of seven fungi pathogenic to soybean [Glycine max (L.) Merril] seed. Both cells and the supernatants of two Brazilian strains, 07-1 and 27-1, together with ATCC 12472(T) were strongly antagonistic to six out of the seven fungi. The antifungal activity of the Brazilian strains to Fusarium sp., Phomopsis sp. and Cercospora kikuchi was consistently stronger than that of ATCC 12472(T). In addition, the two Brazilian strains, but not ATCC 12472(T), were effective against Corynespora sp., and all three strains and their supernatants were equally effective against Aspergillus sp. and Colletotrichum sp. None of the strains had antifungal activity against Botroyodiplodia sp. Three potential mechanisms related to the antibiosis were investigated: violacein toxicity, cyanide production and chitinolytic activity; however, it was not possible to associate any of them with the antifungal activity. The results highlight the biotechnological potential still to be explored within the poorly characterized microbial biodiversity of the tropics.

Methods of screening Bt collections on the basis of feeding bioassays can be misleading with regards to identifying more promising isolates for biocontrol purposes if physiological differences are not considered. The consequences and implications of these findings for the development of experimental systems that depend on toxicity bioassays to identify alternative Bt strains and entomotoxins with practical applicability have been discussed.

An. Soc. Entomol. Brasil 29(1): 147-153 (2000) PCR Identification of Cry I Genes in Bacillus thuringiensis Strains that are Efficient Against Fall Armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)ABSTRACT -Fall armyworm, Spodoptera frugiperda (J. E. Smith), is the most important maize insect pest in Brazil and its damage can reduce yield up to 34%. The objective of this work was to utilize the PCR technique to Identify Bacillus thuringiensis (B.t) strains that control S. frugiperda in maize crops. Bioassays showed that 16 strains were very effective against S. frugiperda, 15 of them collected from soil samples and one (T09) obtained at the Institute Pasteur. The DNA of these strains were probed with cryI general primers and their proteins were analised by SDS-PAGE eletrophoresis. All strains present positive results for cryI genes. To further characterize these strains, specific cryI primers were employed. PCR technique showed that some strains harbour the same cryI genes. The only difference was the amplification of an unexpected fragment of approximately 160bp when a mixture of cryIB and cryID specific primers was used. Analysis by phase contrast microscope showed that crystal proteins produced by these strains were all bipyramidal crystals. Also, eltrophoretic analysis of proteins by SDS-PAGE showed the same protein banding pattern for most of the strains.

A survey of the natural enemies of S. frugiperda larvae was done during the years of 1992/93 and 94/95, in Cascavel region, Parana State. The most frequent parasitoids were Campoletis sp. (Hymenoptera: Ichneumonidae), which reached 47.0% of parasitism and Archytas marmoratus (Diptera: Tachinidae), which reached 15.4%. Of all Baculovirus found, 10.8% were NPV (nuclear polihedrosis virus) and only 1% was GV (granulosis virus).

Resumo. O presente trabalho apresenta o desenvolvimento da cultura da soja no estado de Mato Grosso quanto aos insetos-praga associados a essa cultura. Constatou-se que em 1978 essa cultura apresentava seis espécies-pragas principais e nenhuma praga secundária ou esporádica. No ano de 2008, 33 espécies são consideradas insetos-pragas nesta cultura, sendo 10 espécies consideradas pragas principais, 11 espécies secundárias e 12 espécies esporádicas. Esses dados demonstram um aumento superior a 450% quanto à incidência de pragas da cultura da soja, no período 1978 -2008, no estado do Mato Grosso, sendo que as pragas principais tiveram um aumento de 66,67%.Palavras-Chave: Insecta; Mato Grosso; Praga; Sojicultura. Evolution of Insect Pests in Soybeans in Mato GrossoAbstract. This study presents the development of soy crops in the state of Mato Grosso regarding the pest-insects that have been associated to that culture. It was found that in 1978 soybean crops had six main pest-species and no secondary or sporadic pests. In 2008, 33 species were considered to be pest-insects to this culture, 10 of which are classified as main pests, 11 as secondary, and 12 as sporadic pests. These data show an increase of over 450% in the incidence of soybean crop pests from 1978 -2008, in the state of Mato Grosso, with a 66.67% increase in main pests. Nos primeiros anos da década de 1970, o cultivo da soja passou a ser uma nova atividade econômica para o estado de Mato Grosso. Com a chegada da soja, seu cultivo foi mais elaborado, trazendo consigo novos conhecimentos e procedimentos, como a mecanização e a modernização das práticas de cultivo (Berno & Schneider 2007).Com estímulos governamentais os grandes proprietários rurais da região sulista do país expandiram as fronteiras agrícolas com destino ao estado de Mato Grosso e com a chegada desses migrantes inicia-se uma reestruturação da paisagem natural do Centro-Oeste (duarte 1989). Os incentivos governamentais e os subsídios oferecidos para esses grandes produtores fizeram com que não só o espaço passa-se por mudanças, mas a própria agricultura.Segundo Bonato (2000), as perdas de produtividade e da própria qualidade do grão da soja estão ocorrendo devido aos diversos fatores, que estão agindo sobre a cultura no decorrer do seu ciclo e um dos maiores problemas, que entravam o aumento de produtividade das plantas de soja é a ocorrência das "pragas", seguidos por doenças, nematóides e pela competição com as plantas daninhas (chriStofoletti 2009).De acordo com cruz et al. (1995), à medida que o produtor rural no estado de Mato Grosso aumenta seu nível tecnológico e sua área de produção, o mesmo passa a utilizar um sistema mais intensivo de monocultura, e com isso normalmente, tem-se um aumento dos problemas entomológicos, pois o mesmo utiliza produtos químicos de maneira abusiva e inadequada, ocasionando resíduos dos produtos e a eliminação dos inimigos naturais, controlando apenas parcialmente a praga. Desta forma, o presente trabalho foi realizado de 2008 a 2010, através de pesquisas ...

Abstract. Costalimaita ferruginea (Fabricius) (Coleoptera: Chrysomelidae) is the main Coleoptera defoliator of eucalyptus in Brazil and has a strong association with plants of the family Myrtaceae, bein the eucalyptus important for the sectors of energy, paper, pulp and furniture industry. The objective of the present study was to record the occurrence of this Chrysomelidae in eucalyptus plants in Sinop, State of Mato Grosso, Brazil, during the months of November 2010 to January 2011, thus contributing to increase in knowledge on the geographic distribution of this insect and also hypothesize that the Coleoptera may soon become a major pest of eucalyptus in the state of Mato Grosso.Keywords: Attack; Damages; Geographical distribution; Occurrence. Novo Registro de Costalimaita ferruginea (Fabricius) (Coleoptera: Chrysomelidae) em plantas de Eucalyptus sp. (Myrtaceae) em Sinop -Mato Grosso, BrasilResumo. Costalimaita ferruginea (Fabricius) (Coleoptera: Chrysomelidae) é o principal Coleoptera desfolhador de eucalipto do Brasil e possui grande associação com plantas da família Myrtaceae, sendo o eucalipto importante nos setores de energia, papel, celulose e indústria moveleira. O objetivo deste estudo foi registrar a ocorrência desse Chrysomelidae em plantas de eucalipto município de Sinop, Mato Grosso, Brasil, durante os meses de novembro de 2010 a janeiro de 2011, contribuindo assim para o aumento no conhecimento sobre a distribuição geográfica desse inseto e ainda, lançar a hipótese de que brevemente esse Coleoptera poderá ser tornar uma importante praga da eucaliptocultura do estado de Mato Grosso.