Ultrastructure of the eggs of four species of Culicoides Latreille (Diptera: Ceratopogonidae) with a key to the eggs of all studied species by SEM

The ultrastructure of eggs of Culicoides anophelis Edwards, C. fulvus Sen and Das Gupta, and C. huffi Causey are described along with a re-description of C. oxystoma Kieffer based on scanning electron micrographs (SEM). The importance of the distribution and abundance of ansulae in species recognition is demonstrated by compiling the morphology of all species for which data is available for a key to species based on egg morphology. No correlation between egg morphology and phylogenetic placement of species was found although some association between morphology and egg habitat was noted.