ABSTRACT
White grubs (Coleoptera, Melolonthidae) in the "Planalto Region", Rio Grande do Sul state, Brazil: Key for identification, species richness and distribution. The objective of this study was to survey the occurrence and geographic distribution of white grub species (Coleoptera, Melolonthidae) in cultivated and non-cultivated fields of the "Planalto Region", Rio Grande do Sul state, Brazil and develop a key at genus-level. Twenty-eight species from 15 genera and three subfamilies were recorded: Dynastinae, Melolonthinae and Rutelinae. The species or genera recorded for the first time in the state are: Cyclocephala metrica, C. tucumana, Isonychus albicinctus, Liogenys bidenticeps, L. fusca, L. obesa and L. sinuaticeps, Paranomala violacea, as well as unidentified species of Amononyx, Dicrania, Leucothyreus, Macrodactylus, Plectris and Rhizogeniates. Among the species recorded, 23 were associated with winter crops. Only Cyclocephala metrica, Dyscinetus rugifrons, two species of Leucothyreus and one species of the tribe Sericini were not present in cultivated crop fields. Cyclocephala flavipennis and Diloboderus abderus occurred in most of the municipalities sampled, often associated with Plectris sp., C. modesta and C. putrida. The highest richness of melolonthids was concentrated in the northeast of the Planalto region.
ABSTRACT
The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) and the corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), are important pests of corn in Brazil and have not been successfully managed, because of the difficulty of managing them with pesticides. The objective of this study was to evaluate the effect of Bt corn MON810, transformed with a gene from Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) insecticide seed treatment, and foliar insecticide spray using treatments developed for control of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), which is the major pest of corn. The experiments were done under field conditions in early- and late-planted corn in the state of Rio Grande do Sul, Brazil, and in the laboratory. The MON810 corn reduced infestations and damage by D. saccharalis and H. zea. The insecticides used in seed treatments or foliar sprays did not affect D. saccharalis and H. zea infestations or damage levels. The exception was the insecticide seed treatment in non-transformed corn, which reduced early infestations of D. saccharalis. The MON810 corn, therefore, can be used for managing these two pest species, especially D. saccharalis.
Subject(s)
Bacillus thuringiensis , Insect Control , Insecticides , Moths , Pest Control, Biological , Animals , Brazil , Larva , Methomyl , Phenylurea Compounds , Plant Leaves , Plants, Genetically Modified , Seasons , Seeds , Species Specificity , Zea maysABSTRACT
Com o objetivo de verificar a ocorrência de insetos da parte aérea na cultura da soja convencional e geneticamente modificada resistente a glyphosate, realizou-se este trabalho durante a safra agrícola 2004/05, em Cruz Alta, RS, na área experimental da Fundação Centro de Experimentação e Pesquisa (FUNDACEP). A semeadura foi realizada no dia 26/11/2004, no delineamento experimental de blocos ao acaso com parcelas subdivididas e com quatro repetições, em esquema fatorial 2 x 3. O fator A correspondeu à cultivar "CD 214 RR" resistente a glyphosate e à "CD 201" convencional e o fator B correspondeu ao sistema de manejo das plantas daninhas (sem controle, controle mecânico e controle químico tradicional) e com um tratamento adicional (controle químico com glyphosate na cultivar "CD 214 RR"). A utilização da soja geneticamente modificada resistente a glyphosate e a aplicação do herbicida glyphosate alteraram a ocorrência de algumas espécies de insetos-praga e inimigos naturais na parte aérea da soja.
The experiment was carried out during the crop season 2004/05, in Cruz Alta, RS, Brazil at Fundação Centro de Experimentação e Pesquisa (FUNDACEP) experimental area. The objective was to study the occurrence of insects in conventional and genetically modified herbicide-tolerant soybean. The seeding was done in November, 2004. The experimental design was randomized blocks and factorial scheme. The factor A was represented by the varieties 'CD 214 RR' (glyphosate-tolerant) and 'CD 201' (conventional). The factor B was composed by weed management systems, were b1- without weed control, b2- mechanical control and b3- chemical control with conventional herbicides. An additional treatment was used, where glyphosate application on 'CD 214 RR' was done. Soybean genetically modified herbicide-tolerant and glyphosate application had effects on some pests and beneficial insects in soybean.
