Taxonomic revision of the New Zealand endemic parasitoid genus Rhyssaloides Belokobylskij, 1999 (Hymenoptera: Braconidae)

The New Zealand cyclostome braconid fauna is poorly studied but has a high diversity of Mesostoinae compared to other regions. We redescribe the endemic New Zealand genus Rhyssaloides Belokobylskij, 1999 and compare it to two morphologically similar New Zealand endemics, Zealastoa Quicke & Ward, 2020 and Doryctomorpha Ashmead, 1900. Two new species, Rh. maculatus sp. nov. and Rh. noyesi sp. nov., are described and illustrated. The species Rhyssaloides antipoda Belokobylskij, 1999, which is a parasitoid of the native cerambycid Ambeodontus tristis (Fabricius, 1775), is placed as a junior synonym of Rhyssaloides ambeodonti (Muesebeck, 1941), syn. nov. A key for determining the three known species is provided.

A recent molecular-based phylogenetic study of cyclostome taxa (including several genera of Mesostoinae) (Quicke et al. 2020b) showed Rhyssaloides is sister to Doryctomorpha, while the morphologically similar Zealastoa is sister to Metaspathius. All four genera formed a distinct New Zealand clade separate to other included mesostoine genera.
In this paper, we undertake a revision of the endemic New Zealand mesostoine genus Rhyssaloides Belokobylskij and, in so doing, redescribe the genus, treat the three included species, two of which are new, and provide a key to facilitate their identification.

MATERIAL AND METHODS
The terminology used for morphological features and measurements follows Belokobylskij and Maeto (2009). The wing venation nomenclature follows Maeto (2009), with van Achterberg (1993) terminology shown in parentheses. Specimens were examined using an Olympus SZ51 stereomicroscope. Photographs were obtained using a Canon EOS 70D digital camera mounted on an Olympus SZX10 microscope (Zoological Institute RAS, St Petersburg). The images were enhanced, and the plates composed using Adobe Photoshop.
The holotype and most of paratypes of the new species are housed in the New Zealand Arthropod Collection (Auckland, New Zealand; NZAC), with a few paratypes in the Zoological Institute of the Russian Academy of Sciences (St Petersburg, Russia; ZISP). Belokobylskij, 1999 Type species: Rhyssaloides antipoda Belokobylskij, 1999(= Doryctes ambeodonti Muesebeck, 1941, by original designation and monotypy.

Diagnosis
This genus is very similar to the recently described Zealastoa Quicke & Ward, 2020(Quicke et al. 2020b), but differs from it in having fewer (18-28) antennal segments (33-35 segments in Rhyssaloides); mesoscutum smooth and shiny but with many deep setiferous punctures (densely and finely or very finely granulate to coriaceous with punctation in Rhyssaloides); second transverse anal vein (2a) in fore wing absent (present but usually colourless in Rhyssaloides); second radial abscissa (3-SR) in fore wing less than 1.5 × length of the first radial abscissa (r) (2.0-2.8 × in Rhyssaloides); median area of metanotum in posterior half with distinct median longitudinal carina transformed in dorsal obtuse lobe (without such carina and lobe in Rhyssaloides); and the ovipositor shorter than metasoma (much longer in Rhyssaloides).
Rhyssaloides Belokobylskij resembles the New Zealand genus Doryctomorpha Ashmead from which it distinctly differs in the high face (rather narrow in Doryctomorpha), short normal mandible (long and massive in Doryctomorpha), usually glabrous eyes (setose in Doryctomorpha), antennae longer than body (antennae distinctly shorter than body in Doryctomorpha), long tarsal segments of fore and middle legs (short segments in Doryctomorpha), antefurcal or interstitial position of recurrent vein (m-cu) (distinctly postfurcal in Doryctomorpha), second transverse anal vein (a) present (absent in Doryctomorpha), and distinctly sculptured first metasomal tergite (finely coriaceous in Doryctomorpha).

Redescription
Head. Subcuboid or weakly transverse. Ocelli in triangle with base 1.2-1.3 × its sides. Frons not or only weakly concave, without median keel. Eyes glabrous or with sparse short setae. Occipital carina present, fused with hypostomal carina at upper base of mandible. Malar suture absent or sometimes very fine and incomplete. Clypeal suture distinct. Clypeus with wide ventral flange. Hypoclypeal depression rather large and subcircular or weakly oval. Postgenal bridge present but narrow, sometimes very narrow. Palpi rather long and slender; maxillary palpus six-segmented; labial palpus three-segmented; second segment of labial palpi shortened, 0.6-0.7 × as long as its third segment. Scape wide and rather short, without apical lobe and not angled apically. Pedicel subcuboid. First flagellar segment distinctly longer than second segment.
Mesosoma. Neck of prothorax elongated. Pronotal keel present, transverse in anterior third and semicircular in posterior third. Propleural lobe distinct, short and wide. Mesonotum highly and almost perpendicularly elevated above prothorax, entirely densely setose. Median lobe of mesonotum without anterolateral corners, usually with complete or incomplete longitudinal furrow. Notauli deep and crenulate in anterior half or three-fifths, very shallow or absent in posterior half or two-fifths. Mesoscutum with distinct median longitudinal carina complete or in posterior half. Prescutellar depression relatively long, with high median carina. Scuto-scutellar suture present but fine. Scutellum convex, without lateral carinae at least in anterior half. Metanotum with short median carina not transformed in flange. Subalar depression rather shallow and wide. Precoxal sulcus (sternaulus) distinct, relatively wide, straight, oblique and crenulate. Prepectal carina distinct and complete. Metapleural flange short, wide and round apically. Propodeum with basolateral areas and usually areola distinctly delineated by carinae, lateral tubercles wide and short. Propodeal spiracles small and round.
Legs. Fore tibia with rather dense slender spines arranged in narrow row. Hind coxa without basoventral tooth. Hind femur elongate-oval. Hind tibial spurs short, slender, weakly curved; inner spur 0.15-0.20 × as long as hind basitarsus. Basitarsus of hind tarsus 0.6-0.7 × as long as second to fifth segments combined.
Metasoma. First tergite wide and short. First tergite with distinct dorsope and usually long dorsal carinae; spiracular tubercles weakly or almost indistinct, placed in basal third of tergite. Second suture absent or sometimes very fine. Second and following tergites without separate laterotergites; spiracles placed on sides of tergites; third and following tergites covered by rather dense irregular pale setae. Hypopygium rather large, pointed apically. Ovipositor longer than metasoma. Apical part of ovipositor with very wide and low dorsal node, serrate ventrally.

Holotype
Of Rhyssaloides antipoda Belokobylskij, 1999   combined. Width of hypoclypeal depression subequal to distance from depression to eye, 0.4-0.5 × as wide as face. Head strongly and roundly narrowed below eyes.
Mesosoma. 1.8-2.0 × longer than its height. Mesoscutum 0.9-1.0 × as long as maximum width (near tegulae). Median lobe of mesoscutum usually with complete, narrow and shallow median longitudinal furrow, which is deep and wide in posterior half, but sometimes almost indistinct in anterior half. Notauli deep and coarsely crenulate in anterior half, almost absent or absent in posterior half. Prescutellar depression rather deep, with distinct median carina, mainly weakly rugulose, 0.35-0.40 × as long as scutellum. Scutellum with fine and complete lateral carinae. Subalar depression shallow, entirely coarsely rugulose-reticulate, without striation. Sternaulus weakly curved, coarsely crenulate with rugosity, running along anterior 0.6 of lower part of mesopleuron. Propodeum weakly and almost evenly curved posterior, but abrupt in posterior fifth.
Sculpture and pubescence. Vertex densely and finely to very finely coriaceous; frons distinctly densely granulate and sometimes with additional rugulosity; face finely reticulate coriaceous with punctation, sculpture finer below; temple very finely coriaceous to almost smooth. Mesonotum densely and distinctly punctate and additionally coriaceous or finely granulate in interspaces. Mesopleura very finely reticulate-coriaceous, partly almost smooth. Propodeum finely or sometimes distinctly rugulose-reticulate, with coarse carinae delineated areas; areola short and rather wide, pentagonal, but sometimes its anterior carinae (furca) fine and areola almost open anteriorly, 1.1-1.6 × longer than maximum width; petiolate cell rather long and trapezoid; median carina present in basal third of propodeum, but sometimes rather fine, 0.8-1.5 × longer than furca of areola. Hind coxa finely coriaceous to smooth; hind femur densely reticulate-punctate. First metasomal tergite distinctly curvedly striate, with fine reticulation between striae. Remaining tergites completely smooth. Head covered by relatively sparse, short and semi-erect pale setae. Mesoscutum entirely with very densely and shortly yellow setae. Hind tibia with short, semi-erect and dense yellow setae; length of setae on dorsal side about 0.5 × maximum width of hind tibia.
Colour. Body mainly light reddish brown to yellowish brown, rarely mesosoma and metasoma mainly dark reddish brown and partly with almost black spots; mesosoma laterally, first tergite and distal third of metasoma or rarely metasoma entirely reddish brown to dark reddish brown. Palpi pale yellow. Antennae light brown, faintly darkened towards apex. Legs light brown or yellow, basally pale yellow; middle femur in apical third, hind femur in apical third or half and hind tibia basally and in distal third infuscate to reddish brown. Wings faintly infuscate, more distinctly darkened along veins. Pterostigma brown medially, pale marginally. Ovipositor sheath light reddish brown or yellow, dark brown apically.
Metasoma. 0.7-1.0 × as long as head and mesosoma combined. Length of first tergite 1.2-1.4 × its apical width; apical width 1.5-1.8 × its basal width. Length of second and third tergites combined 1.3-1.4 × basal width of second tergite, almost equal their maximum width. Suture between second and third tergites present laterally.
Colour. Body mainly dark reddish brown, often head and mesoscutum reddish brown or light reddish brown; sometimes body light reddish brown or yellowish brown with dark metasoma behind first tergite. Antennae brown to dark brown, pale to yellow basally. Legs yellow basally, but mainly brownish yellow, sometimes not distinctly infuscated. Wings infuscate, without more intensive darkening along of veins. Pterostigma mainly brown or light brown, pale basally.

Remarks
The holotype of Doryctes ambeodonti Muesebeck should be in the Smithsonian Institute (Washington) according to the information from the original description of the species (Muesebeck, 1941). However, the information about this species is absent in the Internet catalogues of the types preserved in the Institute (https://collections.si.edu/), and additional searching could not locate it. Fortunately, some of the paratypes of this species (7 females and 1 male from the original description of 23 females and 2 males) (Muesebeck, 1941) were found in the New Zealand Arthropod Collection, and the images of the best-preserved specimen were produced for this paper.
The comparison of the description and this illustration of Doryctes ambeodonti with the description and paratypes preserved in the ZISP collection allow us to synonymise these species names: Doryctes ambeodonti Muesebeck, 1941 = Rhyssaloides antipoda Belokobylskij, 1999, syn. nov.

Diagnosis
This new species is very similar to Rh. noyesi sp. nov.; the differences between these species are shown below and in the key.
Mesosoma. 1.9-2.1 × longer than its height. Mesoscutum 0.8-0.9 × as long as maximum width (near tegulae). Median lobe of mesoscutum with rather deep median longitudinal furrow in posterior two-thirds, absent anteriorly. Notauli deep and coarsely crenulate in anterior half, completely absent in posterior half. Prescutellar depression distinct, with high median carina, mainly finely rugulose or almost smooth, 0.3 × as long as scutellum. Scutellum with distinct lateral carinae, convex. Subalar depression rather shallow, almost entirely weakly reticulate-rugulose, without striation. Sternaulus weakly oblique, coarsely crenulate, running along anterior 0.6 of lower part of mesopleuron. Propodeum (lateral view) weakly and almost evenly curved in anterior two-thirds, strongly abrupt in posterior third.
Metasoma. 0.7-0.8 × as long as head and mesosoma combined. First tergite weakly and almost linearly widened towards apex, with distinctly spiracular tubercles in basal third and convex wide suboval medial area, length of tergite 1.2-1.3 × its apical width; apical width about 1.8 × its subbasal width. Length of second and third tergites combined 1.3-1.4 × basal width of second tergite, almost equal to their maximum width.
Sculpture and pubescence. Vertex very densely and finely punctate and weakly coriaceous; frons finely coriaceous to almost smooth; face finely coriaceous-punctate, smooth laterally; temple upper very finely punctate and smooth in lower half or mostly. Mesonotum distinctly and densely punctate and finely coriaceous in interspaces. Mesopleuron very finely reticulate-coriaceous, below or medially partly almost smooth. Propodeum rugulose-reticulate in posterior half and laterally; basolateral areas relatively long, mainly densely granulate or coriaceous with short additional rugae along carinae; areola short and very narrow, pentagonal; petiolate areal small and trapezoid; median carina present in basal half of propodeum, 3.5-4.0 × longer than anterior furca of areola. Hind femur almost entirely densely rugulose-punctate. First metasomal tergite with few sparse carinae, almost entirely densely and finely reticulate-granulate. Remaining tergites smooth. Head almost entirely in very dense, relatively long and curved semi-erect yellow setae. Mesoscutum almost entirely in densely and relatively long semi-erect white setae. Hind tibia dorsally with short and long, dense, semi-erect, pale setae; length of long setae on dorsal side about equal to maximum width of hind tibia.
Colour. Body mainly or entirely dark reddish brown, sometimes head mostly, mesosoma dorso-anteriorly and metasoma medially reddish brown. Palpi yellow. Antennae mainly dark brown to black, reddish brown basally. Fore and middle legs yellow, but tibiae at least partly and tarsi almost entirely brownish; hind leg partly yellow, distal two-thirds of hind femur, base and apical third of hind tibia dark reddish brown, hind tarsus reddish brown; all fifth tarsal segments dark brown; sometimes hind coxa brownish yellow. Wings faintly infuscate, apices of radial (marginal) and third radiomedial (submarginal) cells with rather wide and subround dark spots, without or finely infuscate along veins. Pterostigma light brown, darkened apically.

Female
Unknown.

Type material
Holotype