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We developed a DNA assay for bloodmeal identification in haematophagous insects. Specific host cytochrome B gene sequences were amplified by PCR and classified on the basis of their mobility in a heteroduplex assay. In the blackfly #Simulium damnosum s.l.$ (#Diptera$ : #Simuliidae$), human cytochrome B DNA sequences were identifiable up to 3 days following ingestion of the bloodmeal. In the tsetse #Glossina palpalis$ (#Diptera$ : #Glossinidae$) collected from tsetse traps in Ivory Coast, bloodmeals were identified as taken from domestic pigs on the basis of their heteroduplex pattern and DNA sequence. Evidently the cytochrome B sequence shows sufficient interspecific variation to distinguish between mammalian host samples, while exhibiting minimal intraspecific variation. The stability of DNA in bloodmeals, for several days post-ingestion by haematophagous insects, allows PCR-HDA assays to be used reliably for host identification. (Résumé d'auteur)

International audience; Male Lutzomyia longipalpis of two types from Bolivia were compared using isozyme electrophoresis and wing morphometry. One sample (ex Chiflonkaka Cave, alt. 2800 m at Toro Toro, Charcas Province, Potosi Department) was "two-spot" phenotype males (i.e. tergites III and IV with paired pale patches of pheromone glands), whereas two other locality samples (Apa Apa and Imanaco, Sud Yungas Province, La Paz Department) were one-spot male phenotype (only tergite IV with paired pale patches). Multilocus enzyme electrophoresis (using ACON, aGPD, GPI, IDH, MDH, ME, 6PGD, PGM, LAP and PEPB) found no difference between samples from adjacent hen houses at Apa Apa. Nei's standard genetic distance between one-spot samples Apa Apa and Imanaco (5 km apart, 1500 m alt.) was 0,001-0,002, whereas the two-spot males from Toro Toro (800 km away) showed a genetic distance of 0,081 from the one-spot males (Apa Apa and Imanaco). This genetic distance is commensurate with speciation, but may simply be intraspecific differentiation due to "isolation by distance". For comparative wing morphometry, we included additional material of one-spot males from Bolivia (Guyabal, Sud Yungas, La Paz), Brazil, Colombia and Nicaragua. These three other country samples were assumed to be different sibling species in the complex Lutzomyia longipalpis (Lanzaro et al., 1993). Statistics were based on univariate and multivariate analysis. The comparison between size-in and size-free canonical variate analysis (CVA) indicated that the wing morphometric divergence between one-spot and two-spot Bolivian phenotypes was not size dependent and could have taxonomic significance. (Résumé d'auteur)

Human lice (Phthiraptera : Pediculidae) from Africa, America and Europe were electrophoresed for 28 enzymes, with special interest in metabolic factors likely to be involved with insecticide resistance. Zymogram profiles of the body louse (#Pediculus humanus$ L. from France and U.S.A.) and the head louse (#P. capitis$ DeGeer from France, Madagascar, Mali & Senegal) were compared. Only two enzymes, phosphoglucomutase (Pgm) and esterase 3 (Est-3), showed electrophoretic variation. In our starch gel electrophoresis conditions, #P. humanus$ showed three electromorphs of Pgm migrating anodally 6, 11 and 16 mm (designated alleles a, b, c, respectively). Of the putative Pgm alleles, b and c occured in all samples of both species of lice, whereas allele a was found only in #P. humanus$ lab strain from U.S.A. Esterase 3 had four electromorphs migrating 23, 26, 30 and 35 mm (designated allele a, b, c and d). Among putative Est alleles, a was found only in #P. capitis$ from Bamako (all 14 specimens aa homozygotes), allele d was found only in #P. capitis$ from Dakar (39% frequency), whereas Est-3 alleles b and c showed apparently balanced polymorphism in all samples of both #P. humanus$ and #P. capitis$ except from Bamako. Despite the limited amount of isoenzyme variation detected (only 2/31 polymorphic loci), divergences of Est-3 and Pgm among #Pediculus$ populations may be relevant to their biosystematics and resistance. (Résumé d'auteur)