Elimination of protein-food ingested into the crop, and failure of ovarian development in female mosquitoes, Culex pipiens pallens

ABSTRACT. A protein-food rarely activates oogenesis in female mosquitoes when the protein is mixed with sugar and therefore ingested into the crop. A high occurrence of ovarian development occurs, however, when the protein is stored in the midgut. Examination of female C. pipiens pallens fed on egg albumin containing sugar revealed that the protein, once stored in the crop, was easily eliminated without any absorption and that ovarian development occurred only in those few females which retained some part of the ingested albumin for more than 24 h after feeding. Sugar mixed with the albumin was not detected in any excreta of fed females, suggesting that the sugar was digested irrespective of the protein elimination.