The Rearing of Dragonflies from Eggs*

Abstract

In working out the life history of certain trematode parasites which occur as adults in vertebrate animals it was necessary to rear parasite-free dragonflies which serve as intermediate hosts in the life history. Since parasitologists have to rear hosts which are free from certain kinds of parasites at least, it makes the problems of food and feeding more difficult. The literature on the subject of rearing common, well-known species of invertebrate animals in the laboratory is scarce and there is an increasing demand for such knowledge; so that the author deems it worth while to make this information available. The following excerpts are from Needham and Heywood (20, p. 239): “Some eggs obtained in September at Ithaca hatched the following January, having been kept the while in a laboratory of the normal temperature. Doubtless under normal conditions they do not hatch before spring.“ “Mr. F. R. Nevin has raised vicinum from eggs, laid on October 1 by females from this same pond, which hatched, indoors, from November 28 to January 4 and yielded imagoes on May 3 to May 10, after 11 larval instars.