Aphid derived sugars in the neotropical sandfly--Lutzomyia peruensis.

It is known that a sugar meal is a prerequisite for the transmission of Leishmania by sandflies in the laboratory. Lutzomyia peruensis the proven vector of Leishmania peruviana, was caught by aspiration from crevices in rocks near Chaute in the Rimac Valley, Peru, cryopreserved and analysed for sugars using HPLC. The major sugars present are glucose and fructose as well as smaller amounts of sucrose, maltose, melibiose, turanose and a trisaccharide, probably raffinose. The results indicate that the major carbohydrate sugar meal of Lutzomyia peruensis is aphid honeydew. This is the first report of such behaviour in Neotropical sandflies.

Separation of Psychodopygus carrerai carrerai and P. yucumensis (Diptera: Psychodidae) by gas chromatography of cuticular hydrocarbons.

Specimens of two species of sandfly, Psychodopygus carrerai carrerai and P. yucumensis, vectors of Leishmania braziliensis braziliensis in the subandean lowlands of Bolivia, were subjected to cuticular hydrocarbon analysis to ascertain if the technique could separate the females. A high degree of separation (87%) was obtained based on significant differences in the cuticular hydrocarbon composition of these two species. Statistical treatment of the data shows that these species, initially identified by the colour of the mesonotum, can also be distinguished by their hydrocarbons.

Chemical analysis of compounds extracted from the tergal "spots" of Lutzomyia longipalpis from Brazil.

The chemical composition of the compounds contained in the tergal spots of Lutzomyia longipalpis was investigated. Four populations of L. longipalpis were examined, originating from: Sobral, Ceará, Brazil (one spot and two spot populations), Santarém, Pará, Brazil (one spot) and Marajó Island, Pará, Brazil (one spot). The tergal spots were dissected out, extracted in hexane and analysed on a gas chromatograph/mass spectrometer. Two compounds were found, identical to compounds found in earlier studies, but there was no correlation between number of tergal spots and type of compound present. It was suggested that the number of tergal spots could not be used as a marker for reproductively isolated populations, and that analysis of the compound present within the spots might be necessary to characterize potentially good vector populations.