[Host range of drosophila melanogaster C virus among diptera and lepidoptera (author's transl)].

The host range of the C picornavirus of Drosophila melanogaster was studied, using numerous strains of Drosophila together with four other genera of diptera and two species of lepidoptera. C virus was injected into the different hosts and serially passaged in them. The extracts from each passage were biologically assayed on virus free D. melanogaster. Four different situations were found. 1) A high level of multiplication leading, in 45 strains of Drosophilidae, to the early death of the hosts. This phenomenon was particularly related to the subgroup melanogaster and in the dipteron Ceratitis capitata. The titre of the virus in this latter insect was high as in D. melanogaster, but its cellular tropism was wider. 2) An active viral multiplication but without symptoms, in two strains of D. immigrans and in the lepidopteron Galleria mellonella. In these two insects, the viral titre was clearly inferior to that observed in D. melanogaster. 3) Maintenance of the virus, without multiplication in the dipteron Calliphora erythrocephala and the lepidopteron Arctia caja. In these insects, the decrease in virus titre was directly related to the dilution factor at each passage. 4) Rapid disappearance of the virus, in the mosquitoes Culex pipiens and Aedes aegypti. The host range of C virus is compared to that of Sigma virus of Drosophila and of two other picornaviruses of insects.