Parasites of waterfowl, from southwest Texas: III. The green-winged teal, Anas crecca.

Seventy of 72 green-winged teal, Anas crecca, from southwest Texas were infected with parasites. Seventeen species of endoparasites were recorded: Notocotylus attenuatus, Zygocotyle lunata, Typhlocoelum sisowi, Echinostoma revolutum, Hypoderaeum conoideum, Dendritobilharzia pulverulenta, Cloacotaenia megalops, Sobolevicanthus gracilis, Sobolevicanthus krabbeella, Gastrotaenia cygni, Amidostomum acutum, Amidostomum anseris, Tetrameres crami, Echinuria uncinata, Corynosoma constrictum, Polymorphus minutus. Also recorded were five species of ectoparasites: Trinoton querquedulae, Anaticola crassicornis, Anatoecous icterodes, Holomenopon setigerum and Epidermoptes sp. and the sacrosporidian, Sarcocystis rileyi. Anatoecous icterodes is a new host record for A. crecca. Sobolevicanthus gracilis, S. krabbeella, T. sisowi, and D. pulverulenta are new records for A. crecca in North America. Sobolevicanthus krabbeella is also a new record for North America. Fall juveniles had greater mean parasite intensity (29) than fall (19) and spring adults (19). Juveniles were infected with fewer species of parasites (17) than adults (20). Simpson's index was very low (0.11) indicating a diverse parasite fauna. Sorenson's index of similarity indicated that the parasite fauna for green-winged teal from southwest Texas was more similar to the shoveler's, Anas clypeata, parasites reported from southwest Texas (55%) than to green-winged teal parasites reported from eastern Canada (41%) and New Brunswick, Canada (21%).