Brullé (1846) based
Westwoodia on a single female specimen collected from Tasmania.
Provancher (1875) included
Westwoodia in a key to genera of Pimplides and added a short diagnosis which unfortunately omitted the distinctive features of the genus noted in
Brullé (1846). Provancher (1875a) also described the North American species
Westwoodia fumipennis Provancher.
Ashmead (1900) implied that the
Westwoodia of Provancher was not the same as
Westwoodia Brullé by including both in a list of ichneumonid genera.
Morley (1913) did not consider
W. fumipennis to be congeneric with W. ruficeps Brullé, and finally
Townes (1945) formally removed
W. fumipennis from Westwoodia. Unfortunately, Davis (1897) based his redescription of
Westwoodia on the North American species
W. fumipennis, and
Ashmead (1900) incorrectly used longitudinally striate abdomen as a defining feature. Roman (1912) noted problems characterizing the genus when he initially suggested that the type species,
W. ruficeps, might be a synonym of a braconid descibed by Fabricius, but then retracted this statement in a footnote at the end of his paper.
Morley (1913) and
Roman (1915) provided the first useful redescriptions of
Westwoodia, and both added new distributional data.
Morley (1913) noted morphological similarities to the European
Scolobates Gravenhorst and Holarctic
Opheltes Holmgren;
Roman (1915) placed
Westwoodia in the small subtribe Scolobatina with the European
Scolobates and a third genus,
Scolobatina, which Roman described as new based on a single male from an unknown locality in Australia.
Roman (1915) provided a detailed key separating the three genera, and gave additional information on the type species of Westwoodia.
Townes et al. (1961) placed
Westwoodia in Mesoleiini while retaining
Scolobates in Scolobatini, thus retaining the two in the same subfamily while rejecting the closer relationship implied by
Roman’s (1915) classification.
Townes (1970) subsequently presented a new classification of Ctenopelmatinae (= Scolobatinae of Townes). He redescribed
Scolobatina and
Westwoodia and included them with two other genera in his newly described Westwoodiini, while placing the widespread
Scolobates and two New World genera in a separate tribe, Scolobatini.
Gauld (1984), noting problems with the classification proposed in
Townes (1970), combined the westwoodiines and scolobatines into a single tribe, Scolobatini, and synonymized
Scolobatina Roman, 1915 with
Westwoodia Brullé, 1846. Zhaurova (2006) analyzed relationships among genera included by Gauld (
1984,
1997) in Scolobatini and found two well-supported clades to which she applied the names Westwoodiini and Scolobatini.
Catalogs by Dalla (1901, 1902), Townes et al. (1961), Gupta (1987), Yu and Horstmann (1997) and Yu et al. (2005) all treat Westwoodia and confirm that the genus is thus far known only from Australia. Prior to the present study, there was but a single published host record: an unidentified species of Pseudoperga Guerin-Méneville (Pergidae) for W. ruficeps (Gauld 1984). Gauld (1984) reported that he had seen specimens from all states except Northern Territory but did not provide specific localities. Prior to the work of Zhaurova (2006), the only specific locality records for Westwoodia were from Tasmania (the type locality), Fremantle (WA), Adelaide, and “near Melbourne” (Brullé 1846, Morley 1913, Roman 1915). Gauld (1984), when redefining Westwoodia, noted that he had seen four species, though only two were described. Although only a few additional specimens have been acquired since Gauld’s (1984) study, the morphological variation among species is considerable.
Tarsomere shape (Figs 46–57) and the setal patterns of the coxa (Figs 58–59), tibia, and tarsus are important defining features for the species of Westwoodia. Until the work of Gauld (1984), Westwoodia had been characterized in part on the basis of the short, broad tarsomeres (Figs 46–49, 57) of the only known species, W. ruficeps. Scolobatina ruficeps Roman, transferred to Westwoodia and renamed by Gauld (1984) has long, slender tarsomeres (Fig. 54), as do other species described here (Figs 52–53, 55–56). In W. ruficeps, tarsomeres 1–4 are short and broad, with those of the fore leg more distinctly so than the hind leg and much more so in females than males. In addition to size and shape differences, there are differences in setal patterns and the fleshy ventral pad. Westwoodia ruficeps exhibits the most derived states, with marked loss of setae and the presence of exceptionally large, inflatable pads on tarsomeres 2–4 (Fig. 47). Outgroup taxa have slender and uniformly setose tarsomeres with no evidence of ventral pads.