Biological Species confused under the Name Culicoides austeni (Carter, Ingram and McFie)

Abstract

THE age-grading techniques at present widely used in the study of biting Diptera having been found applicable to Culicoides in Gambia, they were used systematically with material referred to C. austeni (Carter, Ingram and McFie). As a result it became apparent that material referable on morphological grounds to this species showed pronounced biological differences correlated with differences in its larval habitat. Hopkins² and Nicholas³ reared this species from rotting banana litter and Gambian material from this habitat agreed with theirs in requiring blood-meals throughout life for maturation. It never mated under laboratory conditions and field observations showed that mating normally occurred in crepuscular swarms. Far more abundant in Gambia, however, was a form of this species which, while morphologically identical, differed in having its larval habitat in the salt-water mangrove swamps of the river estuary. The salt-water form proved to be autogenous in the first ovarian cycle, maturing its first batch of eggs at the expense of the larval fat body without taking a blood-meal. Swarming was never observed in this species and was evidently not obligatory since it mated freely without it under laboratory conditions, even as a single pair in a glass vial.