Notes on a remarkable abdominal structure in some Crossopalpus BIGOT species (Diptera: Hybotidae), with new records from Southeast Asia (Uber bemerkenswerte Strukturen am Abdomen einiger Arten der Gattung Crossopalpus BIGOT (Diptera: Hybotidae), nebst neuer Fundmeldungen aus Stidostasien)

Abdominal modifications in Crossopalpus hirsutipes COLLIN, 1960 and C. aeneus (WALKER, 1871) have been re-examined and illustrated. These paired structures are normally hidden below the posterior edge of third tergite but became expanded in macerated specimens and then resemble a shaving brush. The possible function of these structures is briefly discussed. Crossopalpus hirsutipes is recorded from Vietnam and Cambodia for the first time. A diagno­ sis of this species and figures of the male terminalia are provided.