Based on the fact that in haematophagous Diptera, the basal bodies, groups of six to nine
specialized epithelial cells in the calyx wall within the ovariolar sheath, become granular after ovulation, a
method for rapidly determining parity of the females has been developed. After supravitally staining intact
ovaries with fresh neutral red solution in physiological saline (1:3000-1:5000) for one to three minutes,
granular basal bodies in parous females can be clearly recognized under a stereo-microscope or a compound
microscope with a raised condensor. The advantages of the method are its speed, accuracy and simplicity.
