Xyo pseudohistrix Travassos & Kloss, 1958 (Hystrignathidae)

Carreno, Ramon A., 2018, Pinworms (Nematoda: Thelastomatoidea) from Insects Collected in Mississippi, USA, with description of a new species of Protrellus Cobb, 1920 from the Cockroach Ischnoptera deropeltiformis Brunner von Wattenwyl, 1865 (Blattaria: Ectobiidae), Zootaxa 4531 (4), pp. 567-577 : 574

Xyo pseudohistrix Travassos & Kloss, 1958 (Hystrignathidae)

Measurements. Females (n=2): Body length 3538 ± 265 (3350–3725); maximum width 155 ± 21(140–170); buccal cavity 9 ± 2 (8–10); oral annule length 13 ± 4 (10–15); oral annule width 34 ± 2 (33–35); esophagus 584 ± 30 (563–605); length of anterior corpus groove 65; corpus length 448 ± 25 (430–465); corpus maximum width 43 ± 11 (35–50); isthmus 50; bulb length 90 ± 11 (83–98); bulb width 75 ± 7 (70–80); vulva from anterior end 1968 ± 11 (1960–1975); vulva from posterior end 1570 ± 255 (1390–1750); tail 390 ± 57 (350–430); body width at tail 75 ± 7 (70–80); egg length 110 ± 8 (100–120); egg width 40 ± 4 (33–40); a = 23 ± 1 (22–24); b = 6 ± 1 (6–6.2); c = 9 ± 1 (9–10); V = 56 ± 4 (52–59).

This species is distinguished from H. rigidus in having 32 longitudinal rows of spines rather than 16. Our measurements are consistent with the few data provided in a redescription of the species by Christie (1934). The species described by Christie was considered to be a synonym of Xyo histrix Cobb, 1898 , the type species from Australia. However, Travassos & Kloss (1958) distinguished the North American species as separate from the Australian species. Xyo pseudohystrix was considered a species inquirenda by Hunt (1982) but retained in a more recent revision of the Hystrignathidae (Adamson & van Waerebeke, 1992b) . It was not possible to further clarify the status of X. pseudohystrix in this study. Few records of this species exist, and its taxonomic status is in need of revision.