A method for the rapid recognition of nulliparous and parous females of haematophagous Diptera

Based on the fact that in haematophagous Diptera (e.g. Aedes aegypti, A. togoi, Anopheles gambiae, A. stephensi, Simulium woodi, S. vorax, Chrysops bicolor and Stomoxys calcitrans), the basal bodies, groups of 6-9 specialized epithelial cells in the calyx wall within the ovariolar sheath, become granular after ovulation, a method for rapidly determining parity of the females was developed. After supravitally staining intact ovaries with fresh neutral red solution in physiological saline (1:3000-1:5000) for 1 to 3 min, 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.