title: Derris (Lonchocarpus) urucu (Leguminosae) extract modifies the peritrophic matrix structure of Aedes aegypti (Diptera:Culicidae).
abstract: Aqueous suspension of ethanol extracts of Derris (Lonchocarpus) urucu (Leguminosae), collected in the state of Amazonas, Brazil, were tested for larvicidal activity against the mosquito Aedes aegypti (Diptera:Culicidae). The aim of this study was to observe the alterations of peritrophic matrix in Ae. aegypti larvae treated with an aqueous suspension of D. urucu extract. Different concentrations of D. urucu root extract were tested against fourth instar larvae. One hundred percent mortality was observed at 150 microg/ml (LC(50) 17.6 microg/ml) 24 h following treatment. In response to D. urucu feeding, larvae excreted a large amount of amorphous feces, while control larvae did not produce feces during the assay period. Ultrastructural studies showed tha larvae fed with 150 microg/ml of D. urucu extract for 4 h have an imperfect peritrophic matrix and extensive damage of the midgut epithelium. Data indicate a protective role for the peritrophic matrix. The structural modification of the peritrophic matrix is intrinsically associated with larval mortality.
authors.affiliation: Laboratorio de Biotecnologia, Centro de Biociências e Biotecnologia, Campos dos Goytacazes, RJ, Brazil.
authors.forename: Desiely Silva
authors.initials: DS
authors.lastname: Gusmão
authors.forename: Valéria
authors.initials: V
authors.lastname: Páscoa
authors.forename: Leda
authors.initials: L
authors.lastname: Mathias
authors.forename: Ivo José
authors.initials: IJ
authors.lastname: Curcino Vieira
authors.forename: Raimundo
authors.initials: R
authors.lastname: Braz-Filho
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Alves Lemos
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D007887:Fabaceae / Q000737:chemistry*; D007814:Larva / Q000187:drug effects / Q000648:ultrastructure; D008854:Microscopy, Electron; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology
chemical_list: D010936:Plant Extracts