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Os nematóides são encontrados em quase todos os ambientes do mundo; aproximadamente 10% são parasitas de plantas podendo causar danos em todas as partes vegetais, sendo as raízes seu alvo principal. Os prejuízos financeiros decorrentes da atividade destes parasitas nos diferentes cultivos foram estimados em cerca de R$ 400 milhões anuais. São conhecidas mais de 90 espécies do gênero Meloidogyne; no entanto, as que causam danos econômicos importantes são: M. incognita, M. javanica, M. arenaria e M. hapla. As bactérias com capacidade de causar doenças aos fitonematóides possuem diferentes modos de ação e podem ser encontradas no solo, nos tecidos das plantas hospedeiras e nos próprios nematóides. As principais bactérias estudadas para controle biológico dessa praga são aquelas da rizosfera com capacidade de invadir os tecidos internos das plantas, ou seja, endofíticas facultativas, como Bacillus spp. e Pseudomonas spp., além das bactérias parasitas obrigatórias de nematóides, como o gênero Pausteria. Essa revisão destaca as principais bactérias com potencial de controle de fitonematóides, como B. subtilis, B. firmus e B. thuringiensis as quais têm demonstrado grande eficiência no controle destes parasitas. Os estudos também destacam o potencial de bactérias do gênero Pseudomonas com efeito nematicida principalmente contra os nematóides formadores de galhas (Meloidogyne spp.). Dentre as bactérias parasitas, Pausteria penetrans possui grande potencial de aplicação no controle biológico de fitonematóides, especialmente quando utilizada em conjunto com práticas culturais. Palavras-chave: fitonematóides; fitopatógenos; controle biológico; endofíticos; Bacillus.

ABSTRACT. This study presents data on the color polymorphism in Chau/iogl1alhus flavipes Fabricius 1781 (Coleoptera, Cantharidae), analysing the variations in the emergence pattem of phenotypic classes for elytra color and mating system. The frequency of the phenotypic classes varies signiíicantIy throughout the season (males:X 2 = 59,705; females: X2 = 61 ,0 17; 10 gl; p

A Bt soybean has been recently developed, thus, efficiently regulating the populations of major lepidopteran pests. However, in other cases, these benefits have been reduced or lost because of the rapid evolution of pest resistance to the Bt toxins in transgenic crops. When pest populations are exposed to Bt crops and to refuges (non-Bt plants), the evolution of resistance is governed by the fitness of resistant individuals relative to susceptible individuals for both the presence and absence of Bt toxins. One major ecological concern regarding the biosafety of Bt crops on the environment is their potential effects on non-target organisms, especially predators and parasitoids that play an important role in pest control. This information is important for supporting insect resistance management (IRM) programs and for improving agricultural practices in a crop production system with Bt plants. Before the use of Bt plants for insect pest control in Brazil is adopted, IRM programs should be established to ensure the sustainability of this technology for integrated pest management (IPM). This review presents data on Bt soybean and lepidopteran pests as well as on the importance of natural enemies as a form of biological control, and applications for IPM and IRM.

The phylogenetic relationships of twelve species of Chauliognathus were investigated by studying the mitochondrial cytochrome oxidase I gene. A 678 bp fragment of the COI gene was sequenced to test the hypothesis that the Müllerian mimicry species of the "yellow-black" complex make up a monophyletic clade, separated from species with other colour patterns. The data set was analysed by neighbour-joining, maximum parsimony and maximum likelihood procedures.The results support a single origin of the yellow-black colour pattern during the evolution of the genus, with one main clade formed by Chauliognathus lineatus, C. tetrapunctatus, C. riograndensis, C. flavipes, C. octomaculatus, C. fallax, and another one formed by two species, C. expansus and C sp 1, plus an orange-black-coloured species. The nucleotide divergences found between C. sp 3 (black) and the other species studied fall within the level expected for species from different genera. The similarity of colour patterns of the yellow-black species has been considered an example of Müllerian mimicry by conservation of the ancestral state with some minor modifications.

This paper describes a survey of arthropods in rice-growing areas of Rio Grande do Sul, Brazil, undertaken to identify the main groups of insect pests and their natural enemies present in three producing regions during the stages of crop development. The study was conducted during the crop years 2007/2008 and 2008/2009 in the municipalities of Cachoeira do Sul, Eldorado do Sul and Capivari do Sul. A total of 44,231 arthropods were collected: 26,821 in 2007/2008 and 17,410 in 2008/2009. Spatial and temporal patterns were analyzed utilizing the 28 principal families and applying the Morisita-Horn coefficient and the Detrended Correspondence Analysis (DCA). Both results demonstrated variances of abundance and richness from 1 year to the next in the evaluated areas.The results indicate that the arthropod communities in southern Brazilian rice crop agro-ecosystems are formed of a few families with high abundance and a large number of other smaller families. Among the phytophagous arthropods found, Pentatomidae, Orthoptera and planthoppers were predominant while the natural enemies were mainly predatory mites, spiders, Hymenoptera and Odonata. This study demonstrates that irrigated rice fields located in subtropical areas of the Brazilian South sustain a great variety of arthropods which facilitate studies on bio-diversity conservation and the development of sustainable management of the pests.

In this study, we evaluate spatial and temporal variations of the water's quality used in rice fields. Every 15 days during the different phases of cultivation of the rice-vegetative, reproductive, and maturity-samples were collected from the main irrigation channel, from the surface water in the field, and from the excess-water drainage channel. The differences in the values of 13 variables were analyzed by the analysis of variance system and by the Principal Component Analysis (PCA) technique. The results demonstrate that the values observed for the presence of total coliforms, heat-tolerant coliforms, and pH were higher in the irrigation water and that the calcium and magnesium components were greater in the drainage water. The PCA results indicate that three groups of variance exist and that these three account for 77 % of the observed variances. The first principal component, (39 % of the variances), includes the variables pH, phosphorus, potassium, carbon, and turbidity; the second (28.1 %), calcium, magnesium, and conductivity; while the third accounts for only 9.9 % of the variation and incorporates the variable biological thermotolerant coliforms. The spatial pattern resulting from the distribution of the sampling locations as regards the first two principal components indicates a difference between the irrigation and drainage waters. The variables of the first and third items (except for the turbidity in the second component) reach higher values in the irrigation water, while the variables associated with the second component have higher values in the drainage water. The information provided is important for the analysis of the influence exercised by plantation management decisions on the microbiological, physical, and chemical quality of the water. The results confirm the ability of paddy rice field to filter out some of the chemicals and coliforms from the irrigation water as it passes through the agro ecosystem.