Ultrastructure of the Eggs of Seven Flea Species (Siphonaptera)

Eggs of seven flea species representing five families, Ctenocephalides felis (Bouche) (Pulicidae), Orchopeas leucopus (Baker) and Aetheca wagneri (Baker) (Ceratophyllidae), Conorhinopsylla stanfordi Stewart and Epitedia faceta (Rothschild) (Hystrichopsyllidae), Sternopsylla distincta texana (C. Fox) (Ischnopsyllidae), and Craneopsylla minerva (Rothschild) (Stephanocircidae), were examined with a scanning electron microscope and are described from the resulting micrographs. In the Pulicidae and Ceratophyllidae the individual outer chorionic cells are not visible; the egg surfaces are covered uniformly with small, nodular tubercles. In contrast, the Hystrichopsyllidae and Ischnopsyllidae have a prominent, raised reticulum, very heavily constructed in the latter, delineating the chorionic cells. The single representative of the Stephanocircidae has only a faintly embossed chorionic reticulum. All of the species examined except E. faceta and C. minerva (both with a single micropylar opening) have multiple micropyles at the posterior end. C. felis, O. leucopus, A. wagneri , and C. stanfordi also have multiple aeropyles at the anterior end (these are lacking in S. d. texana ). Lateral aeropyles, consisting of small groups of pores often associated with small mounds in the chorion, are present (maximum of two seen on any one egg) in all species except E. faceta, C. stanfordi , and C minerva .