Discovery of Rodrigama Gauld in the Old World, with description of two new species (Hymenoptera, Ichneumonidae, Poemeniinae)

Two new species of the genus Rodrigama Gauld are described: R. gauldi sp. n. from Ryukyus, Japan and R. takakuwai sp. n. from Taiwan. Th e genus Rodrigama was known from a single Costa Rican species and these new species are the fi rst representatives of the genus in the Old World. Th e distribution of these species in the Palaearctic/Oriental Region reinforces the hypothesis that the Poemeniinae originated in the north temperate region and diversifi ed into tropical regions, and that the Costa Rican R. gamezi is a relict of a group that once had a wider distribution. A key to the species of the genus is provided.


Introduction
, in their phylogenetic analysis of Pimpliformes, demonstrated that Rodrigama occupies a basal position in the Poemeniinae and is the sister group to higher poemeniines, and accordingly bestowed tribal status (Rodrigamini) on the one species known at the time, Rodrigama gamezi Gauld.Th ey regarded the genus Pseudorhyssa Merrill as the sister group to all other Poemeniinae and erected the tribe Pseudorhyssini.Pseudorhyssa is somewhat aberrant among the subfamily and Quicke et al. (2009) noted that it might deserve its own subfamily status.Th e apparently primitive genus, Rodrigama, was known from only a single species, R. gamezi, described from Costa Rica.Th e isolated distribution of this archaic genus in Mesoamerica was anomalous and did not fi t the hypothesis of an Holarctic origin of the Poemeniinae (Wahl and Gauld 1998).Recently, two new species of Rodrigama have been found, one from the Ryukyu Archipelago, at the Oriental and Palaearctic boundary in Japan, and another from Taiwan.

Materials and methods
Type specimens of the two new species are preserved in the collection of Osaka Museum of Natural History (OMNH), except the holotype of R. takakuwai in the Taiwan Agriculture Research Institute, Taichung, Taiwan (TARI) and one paratype of R. gauldi in the Natural History Museum, London (BMNH).Th ree paratype specimens (two females and one male) of the genotype, Rodrigama gamezi Gauld, 1991, preserved in BMNH, were examined for comparison.A scanning electron microscope (KEYENCE VE-7800) was used for detailed observation of external morphology of adults.Th e image of the specimen of R. gamezi was taken using a Canon EOS 450D digital camera and Pentax 50 mm macro lens.Several partially focused images were combined using Helicon Focus v. 4.80.Terminology of adult morphology follows Gauld (1991).
Diagnosis.Rodrigama can be distinguished from all other poemeniines by either of the following: 1) paired antero-lateral and postero-lateral oblique grooves delimiting a central rhombic area on the second metasomal tergite; 2) fused tergite and sternite of the fi rst metasomal segment and can be readily identifi ed using Wahl & Gauld's (1998) key to genera.Description.Medium to large ichneumonids with fore wing length 12-26 mm.Apical segment of fl agellum tapered apically, with distal end narrowly truncate; eyes with inner margins parallel; lower face transverse, about 1.3 × as broad as high at narrowest point; clypeus (Fig. 6) moderately large, not divided into basal and apical parts; clypeal margin thin, more or less indented, about 2 × as wide as high; mandible (Fig. 6) stout, with lower tooth slightly twisted forwards, entire mandible evenly tapered, bidentate, with lower tooth distinctly longer and stouter than upper tooth; posterior ocellus separated from eye by 1.4-1.7 × its maximum diameter; occipital carina (Figs 4, 5) centrally narrowly incomplete, mediodorsally slightly dipped; upper part of gena smooth; head in dorsal view with genae of moderate length, barely narrowed behind eyes.Pronotum (Fig. 7) with a mediodorsal posteriorly directed tooth, with strongly impressed and transversely striate groove extending from upper hind corner down to lower corner; upper part of epomia weak and short.Mesoscutum highly polished, sparsely covered with fi ne punctures and pubescence, without transverse rugae; epicnemial carina present, with upper end reaching level of lower corner of pronotum.Propodeum (Figs 8, 18) quite short, convex, with longitudinal carinae weak or absent; pleural carina clearly discernible; propodeal spiracle oval.Metapleuron strongly convex; submetapleural carina complete.Fore wing (Fig. 16) with vein 3rs-m present, defi ning a shortly petiolate, very wide, irregularly rhombic areolet; vein Rs+M opposite or a little basad of cu-a; 2rs-m about as long as M between 2rs-m and 2m-cu; 2m-cu with two bullae; Cu1b shorter than abscissa of Cu1 between 1m-cu and Cu1a; hind wing with 4-5 hamuli on costal margin proximally.Tarsal claws of both sexes simple, large, symmetrical, abruptly curved, with neither inner tooth nor spatulate bristles; hind leg very slender with tibia and tarsus particularly long and slender, with trochantellus not exceptionally long.Metasoma of female (Figs 1-3) moderately slender, fusiform; tergite 1 19) very long and slender, dorsally smooth and polished, without lateromedian and lateral longitudinal carinae, with spiracles on promontories at centre of tergite; sternite 1 fused to tergite, anteriorly forming cylinder; glymma absent; tergites 2-4 with grooves delimiting more or less rhombic central areas 13,20); last visible tergite extending into fl at, shelf-like posterior prolongation which overhangs cerci (Fig. 14); sternites 2+ to subgenital plate medially indented, latter with small median incision posteriorly; ovipositor moderately stout, projecting beyond subgenital plate by about 4.5 × length of hind tibia, apex somewhat depressed, evenly tapered to point; lower valve dorsolaterally expanded to partially enclose upper, with distinct teeth (Fig. 15); male with metasoma slightly compressed; sternites evenly sclerotized, folded on mid-line; subgenital plate transverse, with posterior margin slightly concave.
Biological notes.Host unknown.Females of R. gamezi were observed fl ying around an old, dead tree, and one was collected whilst probing in an old beetle boring with its ovipositor (Gauld 1991).Subalar prominence yellow (Fig. 1).First to fi fth metasomal tergites brown to dark brown, with posterior whitish band (this band sometimes interrupted medially) (Fig. 1).Pronotum with weak, medially incomplete oblique groove from epomia to ventroposterior corner (Fig. 7).Area dorsal to this groove weakly punctate.First metasomal tergite gradually broadened posteriorly in dorsal aspect, with posterior end much broader than width at anterior 0.2 (Fig. 12 2).First to fi fth metasomal tergites brown to reddish brown all over, never with posterior whitish band (Fig. 2).Pronotum with strongly impressed and transversely striate groove from epomia to ventroposterior corner (Fig. 17).Area dorsal to this groove rather strongly and densely punctate, slightly rugose.First metasomal tergite broadened at anterior 0.1 and slightly narrowed a little posterior to spiracle, with posterior end slightly broader than width at anterior 0.2 (Fig. 19

Rodrigama gamezi Gauld, 1991
Fig. 3 Notes.Gauld's (1991) description is suffi cient for recognition of R. gamezi; we add the following characters for comparison with the two species newly described here: epicnemial carina present on mesoscutum; mesopleural suture mostly smooth, with some faint transverse striations; posterior transverse carina of propodeum strongly raised; fi rst metasomal sternite extending back to about half way between spiracle and posterior margin of tergite 1.A paratype ♀ is illustrated in Fig. 3. Paratypes.3♀,(OMNH), 1♀, 14-20.v(BMNH), otherwise same data as holotype, collected in a Malaise trap operated by K. Sugino.

Rodrigama gauldi
Diagnosis.Th is species can be distinguished from all congeners by the following: pronotum with weak, medially incomplete oblique groove from epomia to ventroposterior corner; area dorsal to this groove weakly punctate; subalar prominence yellow; fi rst metasomal tergite with apical whitish band; tergites 2-5 each with paired whitish transverse markings apically, these markings sometimes fused dorso-medially.
Etymology.We are very pleased to be able to name this species after the late Dr Ian Gauld, who recognised Rodrigama as a basal poemeniine and who has left such a rich legacy of ichneumonid taxonomy.It is a great pity that he did not live long enough to see these additional Rodrigama species.
Diagnosis.Th is species can be distinghished from all congeners by the following: Pronotum with strongly impressed and transversely striate groove from epomia to ventroposterior corner; area dorsal to this groove rather strongly and densely punctate; subalar prominence reddish brown, without yellow mark; metasomal tergites entirely brown to reddish brown, without whitish transverse markings apically.
Description.Female.Length of fore wing 12 mm.Malar space about 0.2 × basal width of mandible.Pronotum (Fig. 17) with strongly impressed and transversely striate groove from epomia to ventroposterior corner; area dorsal to this groove rather strongly and densely punctate, slightly rugose.Mesoscutum in front of scuto-scutellar groove 1.5 × as long as wide in dorsal view; length of pubescence at centre of middle lobe about 3 × as long as distance between adjoining punctures; mesopleuron moderately punctate anteriorly, rather fi nely and sparsely punctate posteriorly, rather densely covered with pubescence; mesopleural suture strongly transversely striate; propodeum (Fig. 18) moderately punctate, transversely striate dorsomedially, with anterior part of lateromedian longitudinal carina present (sometimes very short), without swelling above spiracle; posterior transverse carinae very weak and incomplete.First metasomal tergite (Fig. 19) broadened at anterior 0.1, slightly narrowed a little posterior to spiracle, with posterior end slightly broader than width at anterior 0.2; posterior end of fi rst metasomal sternite at posterior 0.35 between spiracle and posterior end of fi rst metasomal tergite; tergites 2-4 sparsely covered with fi ne punctures and minute pubescence.
Colouration (Fig. 2).Head largely yellow with following parts black: apical half of mandible, frons except narrow yellow stripe extending along inner orbit to top of eye, dorso-median area of vertex and occiput; gena brown above.Pronotum black with yellow elongate marking next to antero-lateral margin on both side, with upper margins yellow posteriorly.Mesoscutum black with pair of yellow longitudinal spots; mesopleuron reddish brown, area between subalar prominence and speculum black; mesosternum black; scutellum black with median yellow triangular marking; scutellum yellow; propodeum dark brown, ventrally reddish brown below lateral longitudinal carina behind spiracle; metapleuron reddish brown with anterior margin blackish.Legs yellowish brown.Coxa, trochanter and trochantellus of fore leg slightly paler.Middle coxa black dorsally.Hind coxa fulvous, dorsally black.Trochanter darkened dorsally, hind femur and tibia reddish brown, latter darkened apically; basal 0.6 of fi rst tarsomere brown.Wings hyaline, slightly tinged with brown; pterostigma brown, with faint brownish spots around junction of of cu-a and Cu1, and on Rs+2r below pterostigma.Metasomal tergites brown to reddish brown.Ovipositor brown, sheath black.Male.Similar to female but smaller.Length of fore wing 8.0-9.5 mm.Body colour similar to that of female; dark stripe on dorsal face of mid coxa reduced; hind femur blackish dorsally; metasoma reddish brown; fore wing without brown spot.
Distribution.Taiwan (central mountainous region).Etymology.Th is species is named after Dr Masatoshi Takakuwa who collected the Holotype.
Biological notes.Host unknown.Adult wasps were hand netted in mature forest of rather high altitude (1,100-1,400m a.s.l.).Both the preceding species and this Taiwanese species have only been found in mature forest.

Redefi nition of the genus
In addition to the characters listed in the original description of Rodrigama, the following characters are shared by all three known species of Rodrigama and also serve to defi ne the genus: apical segment of fl agellum tapered apically, with distal end narrowly truncate; vein 2m-cu of fore wing with two bullae; apex of ovipositor somewhat depressed.On the other hand, the following characters have now been found to be variable within the genus and cannot be used to defi ne the genus: epicnemial carina present ventrally; propodeum with lateral and lateromedian carinae discernible from anterior edge to quite strongly raised posterior transverse carina; fi rst metasomal sternite extending back to a level about half way between spiracle and posterior margin of tergite.Th ese are characters unique to R. gamezi.Wahl and Gauld (1998) recognized the spiracles of the fi rst metasomal tergite on promontories as an autapomorphy of the genus.Th is character is shared by all three members of the genus and reconfi rmed here as an autapomorphy.Wahl and Gauld (1998) incorrectly coded the epicnemial carina as absent in R. gamezi and were incorrect also in their tribal diagnosis of Rodrigamini, as the epicmnemial carina is present in all three species of the genus.Incidentally, the occipital carina of R. gamezi was coded as complete but it is centrally narrowly incomplete.Wahl and Gauld (1998) hypothesized that the Pimpliformes arose in the north temperate region and diversifi ed into the tropical regions, particularly into the Old World tropics, and latterly into the New World tropics.Th is scenario is well supported by the distributions of Acaenitinae and Rhyssinae (Wahl and Gauld 1998;Yu et al. 2005), in which the most derived genera are primarily tropical and the less derived are Holarctic.Th is pattern is also mostly upheld by the Poemeniinae, in which most of the more plesiomorphic genera, i.e.Pseudorhyssa, Poemenia, Deuteroxorides and Neoxorides, are Palaearctic or Holarctic, whereas the derived lineages, Guptella + Cnastis + Ganodes, Eugalta, have radiated into the more equatorial latitudes (Podoschistus is present in the temperate and Oriental realms).Wahl and Gauld (1998) noted an exception in that the Rodrigamini, the second basal-most branch of the Poemeniinae, was represented by one Neotropical species.Th ey suggested that the Costa Rican species was a relict of a group that once had a wider distribution.Discovery of these additional species of Rodrigama in the Ryukyus and Taiwan, at the Oriental and Palaearctic boundary, strongly supports their hypothesis.It suggests a former, wider distribution of the genus in the Holarctic region, now surviving only on the Pacifi c rim of the Old World and in Central America.A similarly disjunct distribution is known, within Ichneumonidae, for the xoridine genus Aplomerus (Townes 1969;Watanabe and Matsumoto 2010;Broad in prep.), known from North America, Japan and Vietnam.