Susceptibility of aposymbiotic Culex quinquefasciatus to Wuchereria bancrofti

Larvae of the mosquito Culex quinquefasciatus originating from Kenya were reared in 0.025 mg/ml tetracycline hydrochloride. Some of the resulting progeny were shown, by electron microscopy and crossing experiments, to have been rendered free of the rickettsia like symbiont Wolbachia pipientis and from these progeny, symbiont-free lines were established. In experimental feedings on infected human volunteers and on cryopreserved microfilariae, the aposymbiotic stocks were found to be fully susceptible to the filaria Wuchereria bancrofti. This contrasts with some recently published data on Aedes polynesiensis, from which it has been suggested that rickettsia like symbionts have an important role in the development of filaria in the mosquito.