Howard, Dyar and Knab in their monograph “ The Mosquitoes of North and Central America and the West Indies,” in discussing the rearing of mosquitos, emphasise the importance of larvae in specific determination. They write (Vol. I, p. 181) “ Many species of Culex are of uncertain determination without the associated larvae, while some Aëdes have identical adults, yet dissimilar larvae. The characters of the larvae reside in the modifications of the chitinous appendages of the skin and the arrangement of the hairs. As these are fully retained by the cast skins, it is possible to preserve both the larva and the adult of the same identical specimen, thus assuring absolutely correct associations.”