Halipeurus fallacis Timmermann, 1960

(Figs 11, 18, 37, 51, 61, 68–69)

Halipeurus fallacis Timmermann, 1960: 328, fig. 12. Type host: Bulweria fallax Jouanin, 1955 . Holotype 3 in NHML. Halipeurus (Halipeurus) fallacis; Timmermann, 1965: 149, fig. 91.

Halipeurus fallacis; Zonfrillo, 1988: 74.

Halipeurus (Halipeurus) fallacis; Price et al., 2003: 187.

DIAGNOSIS: Male: habitus as in Fig. 68.; clypeal signature as in Fig. 11; terminalia (ventral view) as in Fig. 37; genitalia as in Fig. 61. Female: habitus as in Fig. 69; clypeal signature as in Fig. 18; terminalia (ventral view) as in Fig. 51.

Measurements of both sexes as in Table 1.

MATERIAL EXAMINED

Types

Ex Bulweria fallax: Holotype 3, allotype Ƥ, Indian Ocean, East of Sokotra, 12o04’N- 57o44’E, 6 Aug. 1953, W.W.A. Phillips (NHML 1953-736).

DISCUSSION: The Timmermann (1960) description of Halipeurus fallacis is brief. Besides measurements and a comparison with H. bulweriae, which he regarded as the closest species, the description includes only one schematic illustration of the male genitalia. Apart from the two types, no additional specimens of H. fallacis have been reported in the literature and I have been unable to obtain any further specimen. Considering the rarity of H. fallacis and the paucity of specimens of Bulweria fallax available in collections, in addition to the difficulties to identify the host correctly (see Zonfrillo, 1988), I include additional illustrations of key features and habitus of both sexes of H. fallacis to facilitate the identification of this species.

The petrel that became the type host of H. fallacis was originally identified and published by Alexander (1954: 489) as Pterodroma aterrima (Bonaparte, 1857), the Mascarene black petrel. That petrel was caught alive on board a ship, examined, measured, sketched, deloused and then released. Jouanin published his new species Bulweria fallax in 1955. Therefore, the host name attached to the lice that became the types of H. fallacis must have been changed to B. fallax at the NHML—albeit without a re-examination of the actual bird—prior to Timmermann’s (1960) publication. The identity of the petrel reported by Alexander (1954) as P. aterrima has been discussed by Jouanin (1957: 19). He admits that the descriptive data given by Alexander (1954) does not clearly fit either Pt. aterrima or B. fallax but, considering the geographical coordinates where the bird was captured, Jouanin (1957: 19) believes it was more likely B. fallax . Obviously, without a voucher specimen to support a definite identification, the identity of that petrel will remain forever in doubt. The uncertainty opens the possibility that the identity of the type host of H. fallacis may be in error. New louse collections from authenticated B. fallax and/or Pt. aterrima will be extremely useful to clarify that uncertainty.