Histological structure of the food canal in Nematocera (Diptera) imago head. 2. Culicomorpha [Russian]

摘要

All the Culicomorpha species studied have a well-developed cibarial pump and variously organized pharynx. The ancestral type of the pharynx is suggested to be present in Dixa (Culicoidea). It is characterized by a sclerotized three-radial pharynx devoid of intrinsic circular muscles, perfect development of anterior and posterior pharyngeal dilators, and the well-developed sphincter system. In Culicidae the pharyngeal apparatus is transformed to a great extent: the posterior pharyngeal pump is hypertrophied and the anterior one is greatly reduced. The species of the Chironomoidea family differ much in the pharyngeal apparatus structure. The pharynx of ceratopogonids and simuliids is similar to that in Dixa and Chaoborus. In Thaumalea and especially in Chironomus, it is with weakly developed dilators, less sclerotized pharyngeal intima, folded epithelium, and by the presence of intrinsic circular muscular fibers, the contraction of which causes a reduction of the pharyngeal lumen.