Lepidoptera genitalia

About: Lepidoptera genitalia is a research topic. Over the lifetime, 10114 publications have been published within this topic receiving 78876 citations. The topic is also known as: Uncus.

Molecular Characterization of Host Strains of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Southern Brazil

Abstract: Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a Neotropical species found from Argentina to the United States of America. In its distribution area, two genetically distinct strains are found that differ in their plant host distribution. The strains are morphologically identical, and they can only be reliably distinguished by molecular markers. In this study, we characterized caterpillars collected in corn, Zea mays L., and rice, Oryza sativa L., plantations in the state of Rio Grande do Sul, Brazil. The mitochondrial haplotype typical of the rice strain was found in 100% of the caterpillars collected from that crop, whereas 83% of the caterpillars obtained from corn were of the corn strain haplotype. A sex-linked tandem repeat element called FR was previously shown to have a strain-biased distribution in North American populations. We demonstrated that the same element is found in Brazilian fall armyworm and that it also organized in large tandem repeat clusters that are most frequently observed in caterpillars collected from rice and that display the rice strain mitochondrial haplotype. These results indicate that the Brazilian and North American fall armyworm populations are virtually indistinguishable with respect to the known genetic markers that are diagnostic of strain identity. Furthermore the data are consistent with other studies suggesting substantial gene flow between these widely separated populations. The strain-biased distribution of the FR element makes it a potentially useful marker to estimate interstrain hybridization frequencies of this species in Brazil.

Large-scale evolutionary patterns of host plant associations in the Lepidoptera

Abstract: We characterized evolutionary patterns of host plant use across about 2500 species of British Lepidoptera, using character optimization and independent phylogenetic contrasts among 95 operational taxa, and evaluated the extent to which caterpillars are monophagous, use woody host plants, and feed concealed. We also analyzed the use of different Angiosperm superorders and related these associations to other key variables. The Nepticulidae, Pterophoridae, and Gracillariidae allowed explicit comparisons between the British fauna and the Lepidoptera worldwide, which indicated that our broad categorizations for Britain are accurate predictors for the global fauna. The first (lower glossatan) radiation of the Lepidoptera started with monophagous, internal feeding on woody Eurosids I. Polyphagy on nonwoody Eurosids I evolved together with the ability to feed externally, but did initially not produce significant radiations. Exposed feeding became associated with radiations in the lower Ditrysia and Apoditrysia and remained correlated with more polyphagy, fewer woody host plants, and increasing use of other Angiosperm superorders. The macrolepidopteran radiation has frequent reversals to monophagy on woody Eurosids I, particularly in taxa that lost concealed feeding. We discuss the general implications of these results and address several key adaptations and constraints that have characterized the major transitions in lepidopteran life histories.

Molecular markers to discriminate among four pest species of Helicoverpa (Lepidoptera: Noctuidae).

Abstract: The four significant pest species in the Helicoverpa genus (H. armigera, H. assulta, H. punctigera and H. zea) are morphologically similar and can only be reliably distinguished through dissection of adult genitalia. Two partial regions of the mitochondrial DNA (mtDNA), the cytochrome oxidase subunit I (COI) and the cytochrome b (Cyt b) genes were amplified by PCR and digested with restriction endonucleases. The restriction patterns, generated by the endonucleases BstZ17I and HphI, demonstrated reliable differentiation of the four Helicoverpa pest species. This technique is fast, reliable and effective at distinguishing specimens irrespective of their life stages and offers support to conventional taxonomic differentiation based on morphological characters.