Two new species and new records of nasal mites of the genus Sternostoma (Acarina: Rhinonyssinae) from birds in Texas.

Two new species and new host and locality records are established for nasal mites of the genus Sternostoma from birds in Texas. Sternostoma tracheacolum Lawrence is reported for the first time from Pipilo fuscus and Pyrrhuloxia sinuata, respectively. Additionally, a new host record for Sternostoma porteri Hyland from Centurus aurifrons and a new locality record for Sternostoma pirangae Pence from Piranga rubra are established. A redescription is provided for Sternostoma augei Amaral from Speotyto cunicularia. Sternostoma crotophagae sp. n. is described from Crotophaga sulcirostris. It differs from the other species of the genus by the heavily sclerotized margins of the anal plate and tiny cribrum, the two small rounded bifuractions of the movable digit of the chelicerae, abscence of dorsal opisthosomal setae (J, Z, and R series), and chaetotaxy of tarsi II, III, and IV which have only 3 ventral club-shaped setae in the distal row (al1, av2, and pl1 with pv1 apparently absent) and 2 club-shaped setae in the more proximal row (al2 and av3 with pv3 modified into a spinelike seta in the more proximal row and al2 and av3 with pv3 modified into a spinelike seta having an enlarged base and pl2 shorter and with a rounded tip). Sternostoma sayornis sp. n. is described from Sayornis nigricans. The new species is most similar to Sternostoma hedonophilum Fain but differs in the absence of enlarged punctate areas around the stigmata, 5 additional pairs of seta on dorsal opisthosoma (Z and R series), absence of gnathosomal and capitular setae, and slight differences in the leg chaetotaxy with al1 and pl1 on tarsi II, III, and IV very long and whip-like and slight differences in the solenidia on and adjacent to the sensorial area of tarsus I. The host-parasite relationships and affinities of the species of Sternostoma from the host family Tyrannidae are briefly discussed and Sternostoma callithrix Fain and Aitken is reduced as a synonym of Sternostoma longisetosa Hyland on the basis of their existing descriptions.