Westwoodia Brullé, 1846

Wharton, Robert A., Roeder, Karl & Yoder, Matthew J., 2008, A monograph of the genus Westwoodia (Hymenoptera: Ichneumonidae), Zootaxa 1855, pp. 1-40 : 7-8

Westwoodia Brullé, 1846

Westwoodia Brullé, 1846: 126 –128. Type species: Westwoodia ruficeps Brullé, 1846 , by original designation. Scolobatina Roman, 1915: 4. Type species: Scolobatina ruficeps Roman, 1915 , by original designation. Synonymized by Gauld (1984), who also renamed the type species Westwoodia longipes .

Diagnosis

Head predominantly orange to yellow, quadrate, with vertex and gena polished, unsculptured or with weak, sparse punctation. Clypeus ventrally more or less truncate, without median tooth. Mandible with ventral tooth distinctly longer than dorsal tooth. First flagellomere with ovoid tyloid patch on basal 0.2–0.4, patch not quite extending to margin above annellus, containing large number of sensilla ( Fig. 19 ). Fore tibia with apical tooth; tarsomeres 1–4 with fleshy ventral pads, at least apically; claws simple. Fore wing with or without areolet; RS arising near base of stigma. Petiole with sternite short, reaching 0.3–0.4 of distance to spiracle; glymma present, deep but narrow. Ovipositor short, with dorsal notch.

Remarks

Relative to other members of the tribe from Australia, the very short first metasomal sternite is a feature shared only with some species of the much more heavily sculptured Dictyopheltes . The small but deep glymma is better developed than in Pergaphaga Gauld and Dictyopheltes but not as large as in Hypopheltes .

The insightful synonymy of Scolobatina with Westwoodia ( Gauld 1984) is supported by the new species described below, which bridge the considerable gap between W. ruficeps and W. longipes . Inclusion of W. longipes in Westwoodia greatly expands the definition of the genus and renders homoplastic some of the character states previously used for separation of scolobatine genera. Thus, none of the previously published keys ( Townes 1970; Gauld 1984, 1997) is adequate.

Gauld (1984) suggested that species of Westwoodia have exceptionally large eggs. The eggs of a specimen of Westwoodia that he dissected were ellipsoidal and 0.6X the length of the ovipositor; there were 109 eggs in the metasoma. We compared eggs from one of the female specimens of W. ruficeps with those from specimens of Netelia Gray and Xorides Latreille collected in Texas, and those of Westwoodia were several times smaller and much more numerous. The observations in Gauld (1984) are still valid relative to the ovipositor, but a more detailed comparison of egg size in ctenopelmatines is needed to put the Westwoodia eggs in proper perspective.

Hosts

Gauld (1984) stated that Australian species of Scolobatini attack sawflies of the family Pergidae and listed a single host for Westwoodia : a specimen of W. ruficeps labelled as having been reared from Pseudoperga sp. The record in question may refer to either Pseudoperga or Pergagrapta Benson (= Pseudoperga Ashmead not Pseudoperga Guerin-Méneville ) since confusion in use of the name Pseudoperga was not clarified until after Gauld (1984) ( Schmidt & Smith 2006). Label data on the material examined provide two specific host records for W. ruficeps , namely Pergagrapta spinolae (Westwood) and the somewhat polyphagous Pergagrapta polita (Leach) on Eucalyptus propinqua H. Deane & Maiden and Melaleuca quinquenervia (Cav.) S. T. Blake. Behavioral observations on pergids being attacked by ichneumonids ( Lewis 1837, 1839; Morrow et al. 1976), host plant data on some specimens, and host plant records in Schmidt and Smith (2006) also suggest the possibility of either Pseudoperga lewisii (Westwood) and/or P. guerinii (Westwood) as hosts. On this basis we predict that P. l e w i s i i is a host of W. ruficeps in Tasmania where the species was first collected and described.

Weinstein and Austin (1995) reared several individuals of an undetermined species of Westwoodia from Perga dorsalis Leach feeding on two species of Eucalyptus L’Hér. The single individual we examined from their study is a specimen of the species described below as W. romani . A second individual of W. romani was reared from an unidentified pergid by Raff, about a year after Raff published what appears to be her last work on pergid sawflies and their parasitoids ( Schmidt & Smith 2006).

Thus, limited data on hosts are available only from W. ruficeps and W. romani . Published records and unpublished label data all point to hosts being restricted to Perginae (i.e., Pseudoperga , Pergagrapta , and Perga Leach ) feeding on either species of Eucalyptus or the related myrtacean genus Melaleuca L.

Phylogenetic Analysis

Four trees of length 34 were produced (CI=70, RI=72), using Dictyopheltes and the undescribed genus as outgroups ( Fig. 67). The results confirmed the close relationship among the populations that were initially treated as variants of W. ruficeps relative to the other species treated here (see discussion of variation under species treatment of W. ruficeps ). The internal relationships in this part of the tree are not particularly stable, as evidenced by the equally parsimonious solutions. Otherwise, W. ruficeps is the sister-group to the remaining species, with W. gauldi sister to a clade that includes W. romani , W. longipes , and W. rodmani .

Figures

FIGURES 19 – 23. Antenna. 19, SEM of Westwoodia ruficeps, tyloid on first flagellomere; 20, W. ruficeps, arrow = tyloid on dried specimen; 21, W. ruficeps, sparsely setose first flagellomere; 22, holotype, W. gauldi, n. sp., arrow = densely setose first flagellomere; 23, W. ruficeps, yellow apical flagellomeres.