RESUMO

ABSTRACT Spodoptera cosmioides (Walker, 1858) is an economically relevant polyphagous moth, widely distributed in the Neotropics and part of the Spodoptera latifascia (Walker, 1856) species group. In this study, we used extensive sampling from different regions to describe the spatial distribution of S. cosmioides in Brazil and evaluate its variability both from morphological and molecular perspectives. Variable coloration and several morphological similarities were found among S. cosmioides and congeners of the S. latifascia complex, diverging from each 0.5 to 3.5% of mitochondrial DNA. The genetic divergence at the species level of S. cosmioides was 0.5% throughout Brazil, and a geographic structure was absent, including shared haplotypes with S. descoinsi Lalanne-Cassou & Silvain, 1994. Spodoptera cosmioides was found in all six biomes of Brazil, with the highest abundance recorded in the Cerrado, followed by the Amazon, Atlantic Rainforest, Caatinga, Pantanal, and Pampa.

RESUMO

BACKGROUND: The invasion of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) into the New World has made it possible for this pest to hybridize with a native American species, H. zea (Boddie), under natural conditions. We investigated the viability and development of hybrids of these two Helicoverpa species. We reared the parental species and evaluated crosses between H. armigera males and H. zea females and vice versa, two intercrosses between hybrids, and eight backcrosses between hybrids and parental species. We estimated the length of immature stages, fecundity, survival, sex ratio, and heterosis. RESULTS: Although hybridization occcurred, with heterosis during the development of immatures, reproductive incompatibilities also were observed between the parental species and between hybrids from subsequent crosses. The interspecific crosses between hybrids and backcrosses confirmed the possibility of introgression events and their perpetuation in field populations. The results indicate that hybridization events are favored at high population levels, while at low population levels the 'species identities' will be maintained. CONCLUSIONS: The possibility of interspecific gene flow and its perpetuation through successive crosses and backcrosses suggests several recommenations for management. Populations of both species should be maintained at an equilibrium level to reduce the chance of interspecific crosses, which are presumably more likely to occur during pest outbreaks. The existence of hybridization and resistance to different active pesticide ingredients should be monitored. All practices related to managing the resistance of these pests to chemical and biological insecticides should be systematized to reduce the chance of selecting for resistant individuals.

Assuntos

Mariposas , Zea mays , Animais , Feminino , Humanos , Vigor Híbrido , Hibridização Genética , Masculino , Mariposas/genética , Controle de Pragas

RESUMO

Abstract Antispastis Meyrick, 1926 is a poorly known genus of leaf-mining micromoths endemic to the Neotropics, with still uncertain taxonomic position within the Yponomeutoidea. In the present study, the egg, larva and pupa of A. clarkei Pastrana, previously known only from Argentina, are described and illustrated with the aid of optical and scanning electron microscopy. Data on life history, including histology of the mine, are also provided. Family placement of the genus is reassessed based on comparison of morphology and DNA sequences with closely related lineages. The larvae form blotch mines on the upper surface of Solanum L. (Solanaceae) leaves, feeding on palisade parenchyma in all instars. Pupation occurs outside the mine, in an inverted basket-like, large-meshed cocoon constructed on the plant surface. DNA analysis of Cytochrome oxidase I gene of A. clarkei revealed interspecific differences averaging 10% with A. xylophragma, which provided species separation matching morphological differences. Antispastis was closely related phylogenetically to Digitivalva, clustering in the Acrolepiinae together with the genera Acrolepia and Acrolepiopsis, and ultimately placed within Glyphipterigidae. The geographical distribution of A. clarkei is expanded to the Southern Atlantic forest (Rio Grande do Sul and Paraná states, Brazil).

RESUMO

ABSTRACT During recent studies performed in the Atlantic Forest, a new species of Phyllocnistinae (Gracillariidae), Phyllocnistis hemera sp. nov., leaf miner of Daphnopsis fasciculata (Thymelaeaceae) was discovered. The adults are described and illustrated as well as the immature stages, with notes on natural history including a description of the leaf mine. Additionally, DNA barcode sequences were compared to other representatives of Phyllocnistinae to test for the specific status of P. hemera and to infer phylogenetic relationships. This is the fifth species described for the genus Phyllocnistis in the Atlantic Forest and the first record of a gracillarid mining Thymelaeaceae leaves.

RESUMO

ABSTRACT The Neotropical micromoth genus Leurocephala Davis & Mc Kay, 2011 (Lepidoptera, Gracillariidae) was originally described to include only the type species, L. schinusae Davis & Mc Kay, 2011, whose leaf miner larvae are associated with Anacardiaceae in Argentina, Brazil and Paraguay. An integrative analysis including morphology, life history and DNA barcode sequences revealed that specimens collected on Schinus molle L. (Anacardiaceae) in the coastal valleys of the Atacama Desert of northern Chile belong to a second species of this formerly monotypic genus. Adults of Leurocephala chilensis Vargas & Moreira sp. nov. are herein described and illustrated in association with the immature stages and life history, and corresponding phylogenetic relationships are assessed based on DNA barcode sequences. This finding provides the first record of Leurocephala from west of the Andes Range, expanding remarkably its geographic range. It is suggested that the extent of diversity within Leurocephala is much greater and that variation in geographic factors and host plant use may have modeled it, an evolutionary hypothesis that should be assessed in further studies.

RESUMO

ABSTRACT Gracillariidae (Lepidoptera) are commonly known by the leaf miner habit found in the larval stage of most species. By using worldwide, public databases on species diversity and DNA sequences available for extant gracillariid species, we determined changes in the rate of taxonomic species descriptions through time, mapped their spatial distributions, examined their phylogenetic diversification, and estimated the number of species yet to be described for the family in the Neotropics. We recovered 185 species, a number that is smaller than that found in any other biogeographic region. However, it was estimated that at least 3875 additional species remain to be described in the region. Phylogenetic diversification showed a pattern of expanding diversity. A few entomologists have been involved with gracillariid taxonomy in the Neotropics, having 39% of the species been described by a single taxonomist. In most of such cases, descriptions were based on the adults only. A few species have been described from biomes known to have some of the greatest diversity on earth, such as the Atlantic Forest. Thus, such a scenario results from low sampling and scarce taxonomic activity that has prevailed for this family of moths in the Neotropics. It may also be associated with their small body size and to the fact that gracillariids do not seem to be attracted to light traps as much as other moths, which make their collection and identification by non experts difficult. We also suggested scientific and political actions that could be adopted to overcome such an unfavorable scenario.

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A field survey of flowering plants used as food resource by the adults of Heliconius erato phyllis (Fabricius, 1775) was carried out in four sites located in Rio Grande do Sul state, Brazil. Samples were taken in preserved areas of the Atlantic Rain and Myrtaceae forests, an Eucalyptus plantation, and an urban park. Adult feeding frequencies on flowers were registered monthly from December 1996 to May 1997, on plants located on previously marked 200 m long transects. Flowers on which H. erato phyllis fed in the field were collected, drawn and morphometrically characterized. Feeding was registered on flowers of twenty-three species, of which seventeen are new records for H. erato in Brazil . The use of a given plant varied among localities, as a function of its corresponding abundance. The most visited flowers were those of Lantana camara L. and Stachytarpheta cayennensis (Rich.) Vahl, followed by Dahliapinnata Voss in the urban site. The data suggest the existence of size and shape convergence between the proboscis and the small, tubular flowers upon which H. eratophyllis feeds. They also indicate that H. eratophyllis adults have an opportunistic nectar feeding / pollen gathering habit, using several of those flowers available in a given time and locality that fit such a morphometrical pattern. Since plant species of both primitive and derived families are used, there is no indication that phylogenetic constraints play a major role in this association, nor that color of flowers, growth pattern or size of the plants are relevant in determining their use by H. erato phyllis.