The occurrence of roubaud's “race autogene” in a German strain of culex pipiens in England: With notes on rearing and bionomics

An account is given of the discovery of ROUBAUD'S “Race autogéne” in a strain of Elberfeld C. pipiens sent from Germany to England. 2. The validity of the “autogenous” race as far as concerns the British species was tested, proving that the latter were incapable of the “autogenous” type of development. 3. A description is provided of the special technique employed in establishing a flourishing strain of the Elberfeld mosquitoes at the Wellcome Entomological Field Laboratories in England. 4. The effect of blood ingestion by the females prior to the laying of “autogenous” eggs has been investigated, and indicates that the consumption of blood has no subsequent effect on these ova. 5. On the other hand, it is shown that blood ingested by the females after the “autogenous” eggs have been laid, results in the production of rafts which contain a much larger average number of ova than are contained in the “autogenous” rafts. 6. It has been demonstrated that the “autogenous” faculty in the Elberfeld mosquitoes is preserved unaltered over, at least, six “blood generations.”