Abstract
Observations are reported on diapause and laboratory breeding of Phlebotomus perniciosus Newst. and P. ariasi Tonnoir, the two phlebotomine sandflies incriminated as vectors of visceral leishmaniasis in southern France. Previous field studies had suggested that both species are univoltine in southern France, but the present laboratory investigations showed that diapause is obligatory for neither species. Temperature (both species) and photoperiod (P. perniciosus) were found to affect diapause-induction, and diapause was commonly determined before the overwintering stage (the fourth-instar larva). The results showed that P. perniciosus can be mass-reared for at least three uninterrupted generations each year if it is maintained at 28°C in LD 17:7. Further investigations are needed if P. ariasi is also to be bred in sufficient numbers for epidemiological experiments; its colonisation was prevented primarily by low fertility, and attempts at forced insemination were unsuccessful.