title: On first-stage larval resistance under controlled conditions of three species of nematodes of the family Protostrongylidae Leiper, 1926.
abstract: A study was made on the survival of the first larval-stage of three species of the Family Protostrongylidae (Cystocaulus ocreatus, Muellerius capillaris and Neostrongylus linearis). At every temperature (5, 12, 20, 26 and 36 degrees C) and humidity (100, 70 and 30%) combinations, the species which needed the least time to reach the pre-established (50, 75 and 95%) mortality rates was Neostrongylus linearis. In all cases Muellerius capillaris was the species needing the longest time to reach the same mortality percentages (rates). The direct relationship between the survival capacity of each species and their relative abundance in the grazing zone of the sheep used as a source of larvae studied is also discussed. The comparison of our results with those of other authors is made on the basis of an adaptive relationship between the species of parasites studied and their definitive hosts.
mesh_terms: D000818:Animals; D005243:Feces; D007814:Larva; D009349:Nematode Infections / Q000209:etiology / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000209:etiology; D013320:Strongyloidea / Q000254:growth & development* / Q000302:isolation & purification