Abstract: The structure of proventriculus of 14 flea species was studied by means of dis section, histological section and scanning electron microscopy. They include Tunga callida, Pulex irritans, Ctenocephalides felis felis, Xenopsylla cheopis, Vermipsyllaalakurt, Lentistivalius affinis, Neopsylla specialis specialis, Neopsylla dispar fuki enensis, Ctenophthalums eothenomus, Leptopsylla segnis, Macrostylophora euteles,Nosopsyllus wualis bo-seensis, Monopsyllus anisus, Syngenopsyllus calceatus. Theresults are summarized as follows. The external shape of proventriculus could be divided into four types: globular,ellipsoid, tubular and coho truncado. There are altogether twelve types of the apical shape of proventricular spines, I.e., (1) hooked, (2) curved and forked, (3)lobular, (4)acicular, (5) Spearhead, (6) flaring, (7)W-shaped, (8)big forked,(9) small forked, (10) sabre-shaped, (11) cone and (12) ligulate. There is a series of lateral teeth on the spines and the distribution ranges are one half, one-third,one-fourth, two-thirds or throughout the entire length of the spine. The proventri cular spines of the vector fleas of plague, Pulex irritans and Xenopsylla cheopis,have similar features: the spines being broad, long and strongly sclerotized; lateral teeth distributed densely and over one half of the spines. It seems that these structures favour the growth and aggregation of bacteria. However, the teeth are lacking in Verrnipsylla alakurt and Leptopsylla segnis. The proventriculus is absent in Tungs callida, a characteristic of the species.

Key words: fleas——proventriculus——proventricular spines