A review of the genus Geraldus Fitton (Hymenoptera: Ichneumonidae: Banchinae), with description of a new species Author Broad, Gavin R. text Journal of Natural History 2010 2010-05-24 44 23 - 24 1419 1425 http://dx.doi.org/10.1080/00222931003678800 journal article 10.1080/00222931003678800 1464-5262 5209729 Geraldus fittoni Broad , sp. nov. ( Figure 3 ) Female Fore wing length 6.2 mm ; areolet sessile dorsally, pentagonal, with vein 3 rs-m slightly shorter than 2 rs-m ; vein cu-a separated from vein Rs&M by 0.8 times length of cu-a ; hind wing with abscissa of vein Cu 1 between M+Cu and cu-a 0.15 times as long as cu-a . Clypeus basally convex, then flattened with apex notched and slightly outcurved ( Figure 2B ). Antennal scrobes deep and coriaceous; antenna slenderer than in G. cambrensis , first flagellomere six times as long as apically broad, with all flagellomeres slightly widened apically. Head with temples long, slightly widened behind eye and slightly longer than dorsal length of eye. Legs not spiny; tarsal claws less curved, longer than in G. cambrensis , subapical accessory tooth shorter ( Figure 2D ); hind leg very long (slightly longer than body), slenderer than G. cambrensis , hind coxa not robust, about 0.6 times length of first metasomal tergite, hind tibia slimly clavate; inner hind tibial spur 0.3 times length of basitarsus. Head and thorax coriaceous, with some inconspicuous punctures ( Figure 2B ); meoscutum with shallow notauli, extending back to slightly anterior of front edge of tegulae; propleurum with a ventroposteriorly directed lobe; mesopleurum with epicnemial carina not quite reaching front edge of mesopleurum, sternaulus absent; propodeum coriaceous, lacking carinae except for posterior trace of pleural carina; propodeal spiracle ovoid, about twice as long as medially wide. Metasoma mostly impunctate, shining, some sparse punctures on basal half of first tergite; first tergite sub-basally raised, with spiracle at basal 0.3 and glymma deep, basal; sclerotized part of of first sternite reaching 0.15 times length of tergite; laterotergites large, colourless, coriaceous, overlapping ventrally; metasoma elongate, sixth and seventh tergites longer than broad, eighth tergite visible in dorsal view, ovipositor sheaths projecting beyond metasomal apex ( Figure 4 ). Figure 3. Geraldus fittoni , holotype female. Scale bar 1 mm. Colour . Mostly reddish brown; following parts dull yellow: clypeus (except basal ridge), inner orbits up to level of hind edge of ocelli but interrupted adjacent to antennal scrobes, subalar prominence, upper part of epicnemium, anterior edge of mesoscutum laterad and slightly internal of notauli, strip on lower, posterior edge of pronotum, anterior side of fore coxa; following parts black: antennal flagellum, pedicel and posterior side of scape, patch around tentorial pits and upper corner of mandible, transverse groove of pronotum, groove above subalar prominence, upper posterior edge of mesopleurum, lower posterior corner of mesopleurum, vertical anterior groove of propodeum, posterior edge of propodeum, narrowly at ends of trochantelli; wing membrane hyaline, venation reddish brown. Figure 4. Geraldus fittoni , metasoma. Male Unknown. Material examined Holotype female: labelled as ‘ Chile HE13. Puerto Eden , Isla Wellington. 49ºS[A1]. 2500ft. 5.xii.1958 .’ ‘Nothofagus scrub’. The holotype and only known specimen was found recently in a drawer of unidentified Banchinae in BMNH . Etymology This species is named after Mike Fitton, who has recently retired from the Natural History Museum, for all his help and encouragement. Identification of Geraldus species and phylogenetic affinities Species of Geraldus can be recognized as such by the following combination of characters: (1) upper mandibular tooth broad, weakly subdivided; (2) hind wing with abscissa of vein Cu 1 between M+Cu and cu-a much shorter than cu-a ; (3) epicnemial carina present; (4) tarsal claws with accessory tooth. The two known species of Geraldus are restricted to the southern parts of South America, having been collected in Argentina and Chile . The fact that the six known specimens comprise two distinct species may suggest that there are further Geraldus species to be found. No other members of the Banchus group of genera are known to occur in these countries. The species G. cambrensis and G. fittoni are abundantly distinct and can be readily separated from each other on colour pattern, metasoma shape, hind leg morphology and areolet shape, among other differences. However, two synapomorphic characters indicate a congeneric relationship between the two species: the tarsal claws have a distinct accessory tooth and the clypeus has a sub-basal ridge, clearly separating the basal, convex section from the flattened remainder of the clypeus. Fitton (1987) recognized the accessory tooth as a unique apomorphy of Geraldus , but there is a similar structure present on the tarsal claws of Philogalleria , albeit much more resembling a solitary pecten from a pectinate claw (other genera of the Banchus group lack all trace of pectination or accessory teeth). This structure ( Figure 2E ) is present in all four species of Philogalleria present in BMNH. If we assume that the accessory teeth of Geraldus and Philogalleria have a common origin in plesiomorphic claw pectination, then the state found in the two species of Geraldus can be assumed to be derived relative to that in Philogalleria as the morphology of this tooth has diverged more from the original pectination. As both genera seem to be rather basal within the Banchus group ( Fitton 1987 ; results from certain analyses in Quicke et al. 2009 ) it would appear that any trace of pectination has been lost in other genera. Philogalleria species possess two wing venation apomorphies that suggest that they comprise a monophyletic group: fore wing vein 1 m-cu with a distinct ramellus, and fore wing vein cu-a is separated from Rs&M by a distance greater than the length of cu-a . Philogalleria has a wide range of body forms, which Fitton (1987) argued was evidence that Philogalleria and Geraldus are archaic genera within the Banchus group. The discovery of a second species of Geraldus with a body form widely divergent from that of the type species, G. cambrensis , lends weight to this hypothesis, that these are Gondwanan relics of an early diversification.