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Paulo Roberto Valle da Silva Pereira

Bio: Paulo Roberto Valle da Silva Pereira is an academic researcher from Empresa Brasileira de Pesquisa Agropecuária. The author has contributed to research in topics: Aphid & Population. The author has an hindex of 13, co-authored 42 publications receiving 434 citations. Previous affiliations of Paulo Roberto Valle da Silva Pereira include Centro Hospitalar de Vila Nova de Gaia/Espinho.
Topics: Aphid, Population, Pentatomidae, Biology, Infestation

Papers
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Journal ArticleDOI
TL;DR: Information is brought together on biological and ecological aspects of WCM, including its taxonomic status, occurrence, host plant range, damage symptoms and economic impact, and management strategies that have been directed at this mite-virus complex are presented.
Abstract: The wheat curl mite (WCM), Aceria tosichella, and the plant viruses it transmits represent an invasive mite-virus complex that has affected cereal crops worldwide. The main damage caused by WCM comes from its ability to transmit and spread multiple damaging viruses to cereal crops, with Wheat streak mosaic virus (WSMV) and Wheat mosaic virus (WMoV) being the most important. Although WCM and transmitted viruses have been of concern to cereal growers and researchers for at least six decades, they continue to represent a challenge. In older affected areas, for example in North America, this mite-virus complex still has significant economic impact. In Australia and South America, where this problem has only emerged in the last decade, it represents a new threat to winter cereal production. The difficulties encountered in making progress towards managing WCM and its transmitted viruses stem from the complexity of the pathosystem. The most effective methods for minimizing losses from WCM transmitted viruses in cereal crops have previously focused on cultural and plant resistance methods. This paper brings together information on biological and ecological aspects of WCM, including its taxonomic status, occurrence, host plant range, damage symptoms and economic impact. Information about the main viruses transmitted by WCM is also included and the epidemiological relationships involved in this vectored complex of viruses are also addressed. Management strategies that have been directed at this mite-virus complex are presented, including plant resistance, its history, difficulties and advances. Current research perspectives to address this invasive mite-virus complex and minimize cereal crop losses worldwide are also discussed.

97 citations

Journal ArticleDOI
TL;DR: It is concluded that the introduction of H. armigera in Brazil probably occurred before October 2008 and was already present from the extreme southern part of Brazil to the extreme northern part (Amapa) of Brazil in August 2012.
Abstract: This study presents registers of Helicoverpa armigera (Hubner) occurrence to assess its spatial and temporal distribution in Brazil. We used data from collections, especially from the Southern Region, systematic collections in Rio Grande do Sul, occasional collections of caterpillars and adults in different regions of Brazil, as well as literature registers. We conclude that the introduction of H. armigera in Brazil probably occurred before October 2008. We also register that in August 2012 H. armigera was already present from the extreme southern part (Rio Grande do Sul) to the extreme northern part (Amapa) of Brazil.

68 citations

Journal ArticleDOI
TL;DR: Injuries caused by the stink bugs Dichelops furcatus, E. heros and N. viridula were similar in intensity to those by D. melacanthus and the injuries caused by E. heroes were less intense than those of the other species.
Abstract: Injuries caused by the stink bugs Dichelops furcatus (F.), Nezara viridula (L.) and Euschistus heros (F.), compared with Dichelops melacanthus (Dallas), to corn (Zea mays L.) seedlings were studied. The experiment was conducted in a greenhouse in a completely randomized design with five treatments (four species of stink bugs and control, without infestation) using eight replications. In the vegetative stage (V1 to V3) D. melacanthus, at the density of one adult/plant, caused reduction in height, in the number of expanded leaves, in root dry matter, and caused injuries and winding of the central leaves. D. furcatus, E. heros and N. viridula caused injuries, but at different intensities. Injuries caused by D. furcatus and N. viridula were similar in intensity to those by D. melacanthus and the injuries caused by E. heros were less intense than those of the other species.

34 citations

Journal ArticleDOI
TL;DR: The pink hibiscus mealybug, Maconellicoccus hirsutus (Green) and the associated hymenopterous parasitoid, Anagyrus kamali Moursi, 1948 (Hymenoptera: Encyrtidae), are reported for the first time in Brazil.
Abstract: The pink hibiscus mealybug (PHM), Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) and the associated hymenopterous parasitoid, Anagyrus kamali Moursi, 1948 (Hymenoptera: Encyrtidae), are reported for the first time in Brazil. Specimens of the PHM were collected on nine hosts plants, Annona muricata L. (Anonnaceae), Glycine max (L.) Merr. (Fabaceae), Centrolobium paraensis Tul. (Fabaceae), Inga edulis Mart. (Fabaceae), Hibiscus rosa-sinensis L. (Malvaceae), Psidium guajava L. (Myrtaceae), Averrhoa carambola L. (Oxalidaceae), Citrus sinensis (L.) Osbeck (Rutaceae) and Solanum lycopersicum L. (Solanaceae), in four municipalities in the north-northeast of the state of Roraima. The plants C. paraensis, I. edulis and C. sinensis are recorded for the first time as a hosts for PHM. Characteristic injuries observed on the host plants infested by PHM and suggestions for its management are presented.

26 citations

Journal ArticleDOI
TL;DR: O presente trabalho objetivou avaliar o desenvolvimento de Zabrotes subfasciatus (Boh.), praga de graos armazenados, em genotipos de feijoeiro (Phaseolus vulgaris L.) comumente cultivados no Parana e com arcelina, e a possivel resistencia desses materiais ao bruquineo.
Abstract: O presente trabalho objetivou avaliar o desenvolvimento de Zabrotes subfasciatus (Boh.), praga de graos armazenados, em genotipos de feijoeiro (Phaseolus vulgaris L.) comumente cultivados no Parana e com arcelina, e a possivel resistencia desses materiais ao bruquineo. Foram realizados testes em laboratorio (27oC, 50 ± 10% UR, fotofase 12h) com os genotipos TPS-Bionobre, IAC-Una, IPR-Uirapuru, IAPAR 44, IPR Juriti, IAPAR 81, Perola, Carioca e Bolinha, alem de dois outros contendo arcelina, Arc 1 e Arc 2. Os genotipos com os alelos Arc 1 e 2 sugerem resistencia do tipo antibiose, com elevada mortalidade das fases imaturas, e Arc 1, com periodo de desenvolvimento prolongado e drastica reducao de peso de machos e femeas. A resistencia do tipo nao-preferencia para oviposicao nao foi observada para estes dois genotipos. Dentre os genotipos sem arcelina, IAPAR 44 destacou-se como o mais resistente a Z. subfasciatus, pois foi o menos preferido para oviposicao, promovendo baixo percentual de ovos viaveis, longo periodo de desenvolvimento e reduzido peso de machos e femeas. As cultivares Perola, IPR Juriti e Bolinha foram os mais suscetiveis, com alto numero de ovos e ovos viaveis, alem de baixa porcentagem de mortalidade de fases imaturas.

24 citations


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Journal ArticleDOI
TL;DR: The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts.
Abstract: Helicoverpa armigera and Helicoverpa zea are major caterpillar pests of Old and New World agriculture, respectively. Both, particularly H. armigera, are extremely polyphagous, and H. armigera has developed resistance to many insecticides. Here we use comparative genomics, transcriptomics and resequencing to elucidate the genetic basis for their properties as pests. We find that, prior to their divergence about 1.5 Mya, the H. armigera/H. zea lineage had accumulated up to more than 100 more members of specific detoxification and digestion gene families and more than 100 extra gustatory receptor genes, compared to other lepidopterans with narrower host ranges. The two genomes remain very similar in gene content and order, but H. armigera is more polymorphic overall, and H. zea has lost several detoxification genes, as well as about 50 gustatory receptor genes. It also lacks certain genes and alleles conferring insecticide resistance found in H. armigera. Non-synonymous sites in the expanded gene families above are rapidly diverging, both between paralogues and between orthologues in the two species. Whole genome transcriptomic analyses of H. armigera larvae show widely divergent responses to different host plants, including responses among many of the duplicated detoxification and digestion genes. The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts. H. armigera’s invasion of the Americas in recent years means that hybridisation could generate populations that are both locally adapted and insecticide resistant.

242 citations

Journal ArticleDOI
TL;DR: It is shown that both H. armigera subspecies have greater genetic diversity and effective population sizes than do the other species, and no signals for gene flow are found among the six species, pointing toward the emergence of novel hybrid ecotypes.
Abstract: Within the mega-pest lineage of heliothine moths are a number of polyphagous, highly mobile species for which the exchange of adaptive traits through hybridization would affect their properties as pests. The recent invasion of South America by one of the most significant agricultural pests, Helicoverpa armigera , raises concerns for the formation of novel combinations of adaptive genes following hybridization with the closely related Helicoverpa zea . To investigate the propensity for hybridization within the genus Helicoverpa , we carried out whole-genome resequencing of samples from six species, focusing in particular upon H. armigera population structure and its relationship with H. zea . We show that both H. armigera subspecies have greater genetic diversity and effective population sizes than do the other species. We find no signals for gene flow among the six species, other than between H. armigera and H. zea , with nine Brazilian individuals proving to be hybrids of those two species. Eight had largely H. armigera genomes with some introgressed DNA from H. zea scattered throughout. The ninth resembled an F1 hybrid but with stretches of homozygosity for each parental species that reflect previous hybridization. Regions homozygous for H. armigera -derived DNA in this individual included one containing a gustatory receptor and esterase genes previously associated with host range, while another encoded a cytochrome P450 that confers insecticide resistance. Our data point toward the emergence of novel hybrid ecotypes and highlight the importance of monitoring H. armigera genotypes as they spread through the Americas.

106 citations

Journal ArticleDOI
TL;DR: Information is brought together on biological and ecological aspects of WCM, including its taxonomic status, occurrence, host plant range, damage symptoms and economic impact, and management strategies that have been directed at this mite-virus complex are presented.
Abstract: The wheat curl mite (WCM), Aceria tosichella, and the plant viruses it transmits represent an invasive mite-virus complex that has affected cereal crops worldwide. The main damage caused by WCM comes from its ability to transmit and spread multiple damaging viruses to cereal crops, with Wheat streak mosaic virus (WSMV) and Wheat mosaic virus (WMoV) being the most important. Although WCM and transmitted viruses have been of concern to cereal growers and researchers for at least six decades, they continue to represent a challenge. In older affected areas, for example in North America, this mite-virus complex still has significant economic impact. In Australia and South America, where this problem has only emerged in the last decade, it represents a new threat to winter cereal production. The difficulties encountered in making progress towards managing WCM and its transmitted viruses stem from the complexity of the pathosystem. The most effective methods for minimizing losses from WCM transmitted viruses in cereal crops have previously focused on cultural and plant resistance methods. This paper brings together information on biological and ecological aspects of WCM, including its taxonomic status, occurrence, host plant range, damage symptoms and economic impact. Information about the main viruses transmitted by WCM is also included and the epidemiological relationships involved in this vectored complex of viruses are also addressed. Management strategies that have been directed at this mite-virus complex are presented, including plant resistance, its history, difficulties and advances. Current research perspectives to address this invasive mite-virus complex and minimize cereal crop losses worldwide are also discussed.

97 citations