Growth of two phleboviruses after experimental infection of their suspected sand fly vector, Phlebotomus perniciosus (Diptera: Psychodidae).

Phlebotomus perniciosus were infected by intrathoracic inoculation and membrane feeding techniques with two phleboviruses (Toscana and Arbia) isolated in Italy from this sand fly species. Low levels of multiplication of both viruses were detected after intrathoracic inoculation of the sand flies. Only some insects were found infected after oral ingestion of the two viruses. The percentage of flies infected orally was related to the amount of virus ingested. Toscana virus was transovarially transmitted to two larvae of the F1 progeny of orally infected sand flies. No signs of infection were observed after oral infection when unnatural virus-vector combinations were tested, e.g., Toscana virus-P. papatasi or Naples sand fly fever virus-P. perniciosus. The virus concentrations recorded in P. perniciosus experimentally infected with both Toscana and Arbia viruses were similar to those found in naturally-infected sand flies.