ABSTRACT
This study evaluated the effects of the sugarcane borer Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) on cultivars of sweet and biomass sorghum for the selection of resistant cultivars. The present work consisted of two trials, with natural pest infestation. In the first one, 10 sweet sorghum cultivars were analyzed for the following variables: plant height, number of healthy and damaged internodes, gallery position and size, stem infestation level and soluble solids content (°Brix). In the second trial, it was analyzed 16 genotypes of high biomass sorghum, with the same variables above mentioned, in addition to the lignin, cellulose and hemicellulose contents. Among sweet sorghum genotypes evaluated, the genotype CMSXS647 stood out due to the traits: plant height, infestation level, gallery size and soluble solids content. Among the sorghum genotypes evaluated, CMSXS7030, CMSXS7012 and CMSXS7028 presented ideal characteristics for infestation level, plant height and number of lignocellulosic compounds. Such information, in addition to supporting the bioenergy sorghum breeding program, will assist in integrated pest management for sorghum cultivation.
Foram estudados os efeitos causados pela broca-do-colmo Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), em cultivares de sorgo sacarino e biomassa visando seleção de cultivares resistentes à praga. O presente trabalho foi constituído de dois ensaios, com infestação natural da praga. No primeiro, 10 cultivares de sorgo sacarino foram analisadas quanto às seguintes variáveis: altura das plantas, quantidade de internódios sadios e com injúrias, posição e tamanho da galeria, intensidade de infestação de colmos e teor de sólidos solúveis (°Brix). No segundo ensaio, foram analisados 16 genótipos de sorgo biomassa, com as mesmas variáveis supracitadas, além dos teores de lignina, celulose e hemicelulose. Entre os genótipos de sorgo sacarino avaliados, o genótipo CMSXS647 foi o que se destacou em função das características: altura de plantas, intensidade de infestação, tamanho de galerias e teor de sólidos solúveis. Entre os genótipos de sorgo biomassa avaliados: CMSXS7030, CMSXS7012 e CMSXS7028 apresentaram características ideais para intensidade de infestação, altura de plantas e quantidade de compostos lignocelulósico. Tais informações, além de prover o programa de melhoramento de sorgo energia podem ajudar o programa de MIP para a cultura do sorgo, uma vez que o produtor conhece a suscetibilidade dos materiais escolhidos.
Subject(s)
Cell Wall , Biomass , Sorghum , LepidopteraABSTRACT
O objetivo do trabalho foi conhecer as espécies de tripes (Thysanoptera) que atacam pomares de mangueira no semiárido pernambucano. Foram realizadas coletas no período de um ano, em três plantios comerciais da cv. 'Tommy Atkins'. Avaliações semanais foram realizadas em 75 plantas, nos estádios vegetativo e reprodutivo, perfazendo um total de 10.704 amostras em folhas e 390 em panículas. Os espécimes coletados foram levados ao laboratório da Embrapa Semiárido, Petrolina, PE, para triagem dos adultos em microscópio estereoscópico e, posteriormente, enviados à Universidade Federal de Lavras, MG, para identificação. As espécies Frankliniella gardeniae Moulton e Frankliniella Brevicaulis Hood, pertencentes à família Thripidae, representaram, respectivamente, 77 por cento e 23 por cento do total dos tripes coletados. Este estudo relata a primeira ocorrência dessas duas espécies em associação à cultura da mangueira, no Brasil.
The goal of this study was to survey the thrips (Thysanoptera) fauna that attack mango trees in the "semiárido" of Pernambuco. During one year, three commercial orchards of the 'Tommy Atkins' variety were visited. Weekly evaluations were carried out in 75 plants in the vegetative and reproductive stages, totaling 10.704 leaf samples and 390 panicle samples. The adult specimens were sorted using stereomicroscope at the Embrapa Semiárido lab, Petrolina, PE, and sent to the Lavras Federal University, MG, for identification. The species Frankliniella gardeniae Moulton and Frankliniella Brevicaulis Hood, family Thripidae, represented 77 percent and 23 percent of all collected thrips, respectively. This is the first report of these two species occurring in association with mango trees in Brazil.
ABSTRACT
This is the first report of the parasitoid Lysiphlebus testaceipes (Cresson) as a biological control agent of the aphid Aphis gossypii Glover in watermelon crop in Vale do Açu, RN. It was observed that near the harvest, almost all collected aphids were mummified, and after analyzing the emerged parasitoids, the parasitoid L. testaceipes was identified. Therefore, in the future, this species may be included in A. gossypii integrated management programs.
Este é o primeiro relato do parasitoide Lysiphlebus testaceipes (Cresson) como agente de controle biológico do pulgão Aphis gossypii Glover na cultura da melancia, na região do Vale do Açu, Rio Grande do Norte (RN). Observou-se que próximo da colheita quase todos os pulgões coletados encontravam-se mumificados e, na análise dos parasitoides emergidos, constatou-se o parasitismo por L. testaceipes. Essa espécie, portanto, poderá ser incluída em um programa de manejo integrado de A. gossypii futuramente.
ABSTRACT
The minute pirate bugs, Orius spp., are known as predators on several pests as thrips, aphids, spider mites and whiteflies. Orius insidiosus is an important thrips predator, commercially used around the world. However, one of the main problems on biological control of thrips in temperate regions is the occurrence of reproductive diapause in Orius species. This characteristic promotes the interruption of biological control strategies when predators are exposed to short photoperiods. This research had as objective to evaluate the influence of different photoperiod conditions on eggs/nymphs and adults of O. insidiosus in laboratory. The trials were carried out through the combination of eggs/nymphs and adults reared under the photoperiods 10L:14D; 11L:13D; 12L:12D and 13L:11D, at 25±2°C and 70±10 percent RH. The predators were maintained during their pre-imaginal development time under one of the photoperiods and, after being emerged as adults transferred to another photoperiod regime. The predator had a tendency to present longer development time under photoperiod 13L:11D. There was no influence of the different photoperiods conditions on the reproduction of O. insidiosus. The females laid eggs normally during all their lifetime. O. insidiosus is not sensitive to photoperiod evaluated and do not enter in reproductive diapause.
Subject(s)
Animals , Heteroptera/physiology , Longevity , Photoperiod , Nymph , ReproductionABSTRACT
The genus Orius Wolff, 1811 comprises predatory species, with approximately 70 known species. Informations about the genus in Brazil are scarce. Therefore, the aim of this investigation was to identify Orius species present in four localities in the southeastern Brazil. Samples were taken from several plants, and the material screened in laboratory. The genitalia of both sexes were studied and illustrated. Two species were identified, Orius insidiosus (Say, 1832) and Orius thyestes Herring, 1966. O. insidiosus, the most common species, was collected in all of the localities sampled [Lavras (MG), Holambra, Pindorama and Campinas (SP)]. O. thyestes, registered for the first time in Brazil, occurred only in Lavras (MG) and Pindorama (SP). Some morphologic aspects of these two species are also presented