Relationship Between Filtering Activity and Ingestion of Solids by Larvae of the Mosquito Culex Pipiens: a Method for Assessing Phagostimulant Factors

Abstract

Continuous recording of the filtering activity of larvae previously glutted on Chinese ink and individually observed in paniculate suspensions of dried yeast or latex microspheres revealed that the amount of particulate ingested, recorded simultaneously in terms of the displacement of ink rearwards along the gut, was proportional to the cumulative time spent actually filtering. Whether or not particulate material was present, the proportion of time spent filtering was markedly increased by solutes such as yeast extract or adenylic acid which have previously been found to increase the overall rate of ingestion of various non-sapid particulates. Evidently the phagostimulant effect of such solutes results from their stimulating increased filtering, and observation of changes in filtering activity consequent upon the introduction of test solutes into water provides an alternative test for phagostimulant activity.