ABSTRACT
BACKGROUND: A central challenge of DNA gut content analysis is to identify prey in a highly degraded DNA community. In this study, we evaluated prey detection using metabarcoding and a method of mapping unassembled shotgun reads (Lazaro). RESULTS: In a mock prey community, metabarcoding did not detect any prey, probably owing to primer choice and/or preferential predator DNA amplification, while Lazaro detected prey with accuracy 43-71%. Gut content analysis of field-collected arthropod epigeal predators (3 ants, 1 dermapteran, and 1 carabid) from agricultural habitats in Brazil (27 samples, 46-273 individuals per sample) revealed that 64% of the prey species detections by either method were not confirmed by melting curve analysis and 87% of the true prey were detected in common. We hypothesized that Lazaro would detect fewer true- and false-positive and more false-negative prey with greater taxonomic resolution than metabarcoding but found that the methods were similar in sensitivity, specificity, false discovery rate, false omission rate, and accuracy. There was a positive correlation between the relative prey DNA concentration in the samples and the number of prey reads detected by Lazaro, while this was inconsistent for metabarcoding. CONCLUSIONS: Metabarcoding and Lazaro had similar, but partially complementary, detection of prey in arthropod predator guts. However, while Lazaro was almost 2× more expensive, the number of reads was related to the amount of prey DNA, suggesting that Lazaro may provide quantitative prey information while metabarcoding did not.
Subject(s)
Arthropods , Animals , Arthropods/genetics , Arthropods/metabolism , Brazil , DNA/metabolism , Ecosystem , Humans , Sequence Analysis, DNAABSTRACT
The efficacy of the fungus Metarhizium rileyi (Farlow) Kepler, S. A. Rehner & Humber (Hypocreales: Clavicipitaceae) against the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) and the impact on the community of epigeans predators as well as the natural occurrence of native fungal strains were evaluated after sequential sprays in maize. In the first season, the infestation was lower than 0.2 larvae per plant throughout the three fungal sprays and no significant difference was observed in the number of infected larvae among treatments. In the second season, insect population reached an average of 0.8 larvae per plant between the second and third sprays and the number of larvae succumbed by M. rileyi was higher in fungal-treated plots in the following weeks. Molecular characterization of the collected isolates on mummified larvae revealed the introduction of a new isolate did not eliminate the native strain on the fungal-treated plots. In both seasons, the diversity and abundance of predator species in the plots were not affected by any of the treatments. We showed that applications of selected strains of M. rileyi early in the season have no significant impact on the occurrence of natural enemies in maize.
Subject(s)
Metarhizium , Moths , Animals , Larva , Spodoptera , Zea maysABSTRACT
A ocorrência de Isogonoceraia divergipennis (Hemiptera: Psyllidae) foi constatada no estado de Mato Grosso, associada a Poincianella pluviosa (Fabaceae). Até o momento a distribuição da I. divergipennis estava restrita aos estados da Bahia, Minas Gerais, Paraná e São Paulo e esse resultado amplia a área de distribuição do inseto para a região centro-oeste do Brasil. O material de estudo foi obtido em Sorriso, Mato Grosso (S12º32'42,78'', W55º43'32,10") e as coletas foram realizadas no período de setembro de 2013 a maio de 2014.(AU)
Isogonoceraia divergipennis (Hemiptera: Psyllidae) associated with Poincianella pluviosa (Fabaceae) was recorded in the state of Mato Grosso, Brazil, for the first time. Previously, I. divergipennis was known only in the states of Bahia, Minas Gerais, Paraná and São Paulo. Our results extend the known area of distribution of the insect to central-western Brazil. The studied material was from Sorriso, Mato Grosso (S12º32'42.78'', W55º43'32.10"), collected from September 2013 to May 2014.(AU)
Subject(s)
Animal Distribution , Hemiptera , Fabaceae , InsectaABSTRACT
Triplaris americana is a plant that has been applied as ornamental specie and also as natural medicine. Adults and immature stages of Aethalion reticulatum were observed colonizing specimens of this plant in Sinop, MT, Brazil, which represent the first record of this leafhopper colonizing this specie.
ABSTRACT
Um inventário dos Cerambycinae para o Estado de Mato Grosso, em especial a região de Sinop e Claudia, é apresentado neste trabalho. Trinta e quatro espécies, distribuídas em 32 gêneros, são registradas para o estado. Entre elas, quatro são novos registros para o Mato Grosso: Anoplomerus rotundicollis G.-Méneville, 1844; Juiaparus mexicanus (Thomson, 1861); Poeciloxestia ochrotaenia (Bates, 1870); Thoracibidion ruficaudatum (Thomson, 1865).
An inventory of Cerambycinae for the state of Mato Grosso, in particular the region of Sinop and Claudia, is presented. Thirty four species, distributed in 32 genera, are recorded for the state. Among them, four are new records for Mato Grosso: Anoplomerus rotundicollis G.-Méneville, 1844; Juiaparus mexicanus (Thomson, 1861); Poeciloxestia ochrotaenia (Bates, 1870); Thoracibidion ruficaudatum (Thomson, 1865).
ABSTRACT
A incidência de pragas nos coqueirais constitui um fator limitante à exploração, respondendo de maneira significativa pelo depauperamento geral da cultura e também pela redução da produtividade, visto que grande parte do coqueiral brasileiro é cultivado por pequenos produtores sem acesso à tecnologia e a recursos financeiros, o que aumenta ainda mais a precariedade no manejo dessas enfermidades. Dessa forma, o objetivo deste trabalho foi verificar os curculionideos-praga na cultura do coco na região de Sinop, MT a apresentar possíveis métodos de controle. O experimento foi conduzido em três propriedades com cultivo de coco (Cocos nucifera L.) em Sinop, Mato Grosso, Brasil, no período de setembro de 2009 a abril de 2010. Para a coleta foram utilizadas armadilhas Tipo Balde e Tipo Pet espalhadas dentro dos coqueirais e os resultados indicaram o primeiro registro da ocorrência de Metamasius cinnamominus Perty 1830, Metamasius hemipterus hemipterus Linnaeus, 1765 e Rhynchophorus palmarum Linnaeus 1758 no estado de Mato Grosso e de Rhinostomus barbirostris Fabricius 1775, na região de Sinop, além de Homalinotus coriaceus Gyllenhal, 1836 e Amerrhinus ynca Sahlberg, 1823. Dados de distribuição e controle também são apresentados.
The incidence of pests in coconut trees is a factor that limits its cultivation, accounting for a significant depletion of the culture as well as for reducing productivity, considering that, in Brazil, coconut is mostly cultivated by small farmers who do not have access to technology and financial resources, thus increasing the precariousness of disease control. Therefore, the objective of this study was to identify the curculionidae-pests in coconut cultures in the region of Sinop Mato Grosso, and present possible control methods. The experiment was conducted at three coconut (Cocos nucifera L.) farms in Sinop, Mato Grosso, Brazil, from September 2009 to April 2010. Bucket and PET (Polyethylene terephthalate) bottle traps were used to collect the samples. The traps were spread among the coconut trees, and the results indicated the first record of Metamasius cinnamominus Perty 1830, Metamasius hemipterus hemipterus Linnaeus, 1765 and Rhynchophorus palmarum Linnaeus, 1758 in the State of Mato Grosso, and of Rhinostomus barbirostris Fabricius, 1775, in the Sinop region, as well as Homalinotus coriaceus Gyllenhal, 1836 and Amerrhinus ynca Sahlberg, 1823. Distribution and control data are also presented.
Subject(s)
Coleoptera , Cocos , WeevilsABSTRACT
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.
