[Morphofunctional characteristics of the larval mouth apparatus of the chigger, Neotrombicula pomeranzevi (Trombiculidae)].

Gnathostoma of larvae of the chigger mite N. pomeranzevi is situated terminally on the trunk. The base of the gnathostoma is gnathocoxa represented by conglutinated coxae of pedipalps. Gnathocoxa narrows apically and passes into hypostome protruding up to the cheliceral blades. Lateral borders of the hypostome are bent dorsally thus forming a groove in which cheliceral blades are located. The cheliceral blades have a small groove in their internal surface. Larval chelicerea are free because their tactum is missing. Cheliceral apodemes which serve for the insertion of muscles, elevators of chelicerae, are jointed to the base of inner walls of basal cheliceral joints. Lateral gnathostoma bears five-jointed palps which have strong three-apical claws on tibia. Palps do not take part in the attachment of larvae to the host. The dorsal wall of gnathostoma is formed by the epistoma and caudal subcheliceral plate which further is branched into two cheliceral apodemes. Subcheliceral plate and apodemes serve as an attachment place of muscles, dilatators of the pharynx. The mouth opening is situated not far from the apical end of hypostome and goes into a large pharynx passing along the bottom of gnathosoma. On the whole, the mouth parts of larvae are adapted well for sucking liquid food.