Maize plants expressing Cry proteins exhibited FAW control failures in southern Brazil, necessitating insecticidal sprays. In contrast, Bt maize containing the Vip3Aa20 protein remained effective against FAW. However, regardless of the insecticide used against FAW surviving on Bt maize, grain yields were similar. © 2017 Society of Chemical Industry.

Previous research revealed complex diversification patterns in the parthenogenetic weevil Naupactus cervinus. To understand the origin of clonal diversity and successful spreading of this weevil, we investigated its geographic origin and possible dispersal routes and whether parthenogens can persist in habitats under unsuitable environmental conditions. This study is based on samples taken throughout a broad area of the species’ range. We used both mitochondrial and nuclear markers and applied phylogenetic and network analyses to infer possible relationships between haplotypes. Bayesian phylogeographic analyses and ecological niche modeling were used to investigate the processes that shaped genetic diversity and enabled the colonization of new geographic areas. Southeastern Brazil emerges as the original distribution area of N. cervinus. We detected two range expansions, one along natural corridors during the Pleistocene and the other in countries outside South America during recent times. Isolation due to climate shifts during the early Pleistocene led to diversification in two divergent clades, which probably survived in different refugia of the Paranaense Forest and the Paraná River delta. The origin of the clonal diversity was probably a complex process including mutational diversification, hybridization, and secondary colonization. The establishment of N. cervinus in areas outside its native range may indicate adaptation to drier and cooler conditions. Parthenogenesis would be advantageous for the colonization of new environments by preventing the breakup of successful gene combinations. As in other insect pests, the present distribution of N. cervinus results from both its evolutionary history and its recent history related to human activities.

Several parthenogenetic species of broad-nosed weevils exist, some of them of economic importance because of their pest status. Screening of the maternally inherited Wolbachia bacterium in 29 weevils of the tribe Naupactini, using multilocus sequence typing allowed us to assess a significant correlation between asexuality and infection, and suggests an involvement of Wolbachia in the origin of this reproductive mode. The nine Wolbachia strains retrieved from the Naupactini belong to the B supergroup. Phylogenetic analysis of these strains, along with other 23 strains obtained from arthropods and nematodes, supports previous hypotheses that horizontal transfer of Wolbachia amongst species from unrelated taxa has been pervasive.

ABSTRACT. Since its detection in Brazil in 2013, the Old World cotton bollworm Helicoverpa armigera has been reported in Argentina, Paraguay, and Bolivia. Here we present evidence extending the South American range of H. armigera to Uruguay, using polymerase chain reaction and sequencing of the partial mitochondrial DNA (mtDNA) cytochrome oxidase I region. Molecular characterization of this gene region from individuals from Paraguay also supports previous morphological identification of H. armigera in Paraguay. Shared mtDNA haplotypes in H. armigera from Brazil, Uruguay, and Paraguay were identified. Additional surveying of populations in this region will be imperative to better monitor and understand factors that are underpinning its presence and successful adaptation in these South American regions. We discuss our findings with respect to the development of resistance pest management strategies of this invasive insect pest in a predominantly monoculture soybean crop landscape in the Southern Cone region.

Mites Associated with Soybean Crop in Rio Grande do Sul State, BrazilABSTRACT -During the last growing seasons, high infestations of phytophagous mites were observed in the State of Rio Grande do Sul, Brazil, becoming necessary to apply pesticides for their control. The objective of this study was to identify phytophagous and predatory mite species associated with soybean Mononychellus planki Polyphagotarsonemus latus Tetranychus desertorum Tetranychus gigas Phytoseiulus fragariaeTyphlodromalus aripo De Leon) were found. T. desertorum Phytoseiulus fragariae and T. aripo biological control agents in soybean crop was discussed. Among the hypotheses to explain the increasing the dry spells observed in the last few years in the growing season, changes in soybean cropping system that led to increased use of pesticides and utilization of new soybean cultivars with morphological or biochemicals characteristics that favour the development of these mite populations.KEY WORDS: Glycine max L., Tetranychoidea, Tarsonemidae, Phytoseiidae diversos municípios do Rio Grande do Sul, demandando a utilização de pesticidas para seu controle. à soja em dez municípios daquele estado, nas safras de 2002/03 e 2003/04, em cinco cultivares de Mononychellus planki Polyphagotarsonemus latus Tetranychus desertorum Tetranychus gigasPhytoseiulus fragariae & Schicha e Typhlodromalus aripo De Leon). Tetranychus desertorum foi registrada pela primeira vez, associada à soja, no país. P. fragariae e T. aripo foram registradas pela primeira vez em soja. O a expansão progressiva da área cultivada, os veranicos observados nos últimos anos durante a estação desenvolvimento de populações desses ácaros. PALAVRAS-CHAVE:Glycine max L., Tetranychoidea, Tarsonemidae, Phytoseiidae A soja, Glycine max mais importante no Brasil, ocupando mais de 20 milhões de ha, sendo cultivada em mais de 20 estados de todas as regiões e o maior exportador mundial de grãos de soja. A produção, plantas daninhas e ataque de pragas e doenças. Os insetos têm 2005). Entretanto, recentemente, a ocorrência de ácaros tem ganhado importância, tanto pelos danos à cultura quanto pela necessidade de uso do controle químico.