Optimised dietary regimens for the laboratory maintenance of Phlebotomus langeroni nitzulescu (Diptera: Psychodidae)

The optimal feeding conditions for laboratory colonies of Phlebotomus langeroni, the vector of infantile visceral leishmaniasis in Egypt, were investigated. Sugarmeals were offered only before bloodmeals (the SB regimen), only after blood (BS), or both before and after blood (SBS). In each regimen, three different solutions of sucrose (10%, 30% and 50%, w/v) were tested as the source of sugarmeals. In general, the concentration of sucrose used had no significant effect on female longevity, although the longest lived females were those fed on 30% sucrose. Females on the BS regimen were the longest lived whereas those on the SB were the shortest lived. Sucrose concentration did not significantly affect total fecundity, the number of eggs oviposited by females, or the proportion of each egg batch that remained unlaid, but female flies fed 30% sucrose laid more eggs than those fed 10% or 50%, and SBS females laid more eggs than SB or BS. Sucrose concentration and dietary regimen both significantly affected the proportion of laid eggs that hatched, 30% sucrose giving significantly higher proportions than 10% or 50% (in all tested regimens), and the SBS regimen producing higher proportions than the SB or BS. Provision of 30% sucrose before and after bloodmeals is therefore recommended for the laboratory maintenance of P. langeroni.