Adelognathus leucotrochi Shaw & Wahl, 2014

Shaw, Mark R. & Wahl, David B., 2014, Biology, early stages and description of a new species of Adelognathus Holmgren (Hymenoptera: Ichneumonidae: Adelognathinae), Zootaxa 3884 (3), pp. 235-252 : 237-240

Adelognathus leucotrochi Shaw & Wahl , sp. n.

( Figs 1–7 )

Type material: Holotype: UNITED KINGDOM, England, Cumbria, Beetham : ♀ “ Nematus leucotrochus on Ribes uva-crispum with 2 ectos, 26.5.1991, em. 21.4.1992; NMSZ 1993.143” (M.R. Shaw) ( RSME). Condition of holotype: intact . Paratypes: similar data as holotype but often different brood size, collection and emergence dates (collection dates of 24.v.1991, 25.v.1991, 26.v.1991, and 28.v.1991, emergence dates in iv.1992), 36♀, 20♂ ( AEIC, HNHM, NHML, RMNH, RSME, ZINC); UNITED KINGDOM, Scotland, Edinburgh, Grange (suburbs), from same host species, collected 6.vi.1998 and 13.vi.1998, emerged iv.1999 (M.R. Shaw), 6♀ ( RSME). Non-paratype material: 2♀ collected in England (North Yorkshire, Tadcaster , 24.iv.2011 (W.A. Ely )) and Scotland (Edinburgh, Grange, 3.v.1990, (M.R. Shaw )) .

Diagnosis. This species ( Fig. 1 ) can be recognized by the following combination of characters: clypeus, supraclypeal area, and paraocular area yellow ( Fig. 5 ); clypeal apex truncate; flagellomere 4 about 2.2 × as long as wide; subocular sulcus absent; mesoscutum smooth and evenly setose; mesopleuron centrally glabrous; hind coxa white; hind leg with tarsomere 2 about 1.1 × as long as tarsomere 5; vein 3rs-m of fore wing spectral (and areolet superficially appearing open in many specimens); T1 smooth; T2 smooth and with widely scattered minute setiferous punctures medially and laterally, mediolaterally impunctate.

Description. Female. Structure. Scape about 2.0 × as long as pedicel (measured on ventral surface); flagellum about 0.8 × length of hind wing; 12 flagellomeres, flagellomeres 7–12 distinctly thickened ( Fig. 6 ); flagellomere 4 about 2.2 × as long as wide. Clypeus smooth with weak transverse grooves, apex truncate and narrowly reflexed ( Fig. 5 ). Labrum extending beyond clypeus, its apical margin distinctly concave ( Fig. 5 ). Supraclypeal area granulose. Malar space about 0.3 × as long as basal mandibular width. Subocular sulcus absent. Occipital carina not elevated as lamella. Hypostomal carina joining occipital carina before base of mandible. Propleuron weakly convex. Mesoscutum smooth, with minute setiferous punctures separated by 3.0–5.0 times their diameter ( Fig. 2 ); lateral lobes weakly and shallowly foveolate. Epicnemial carina complete, its dorsal end touching anterior margin of mesopleuron. Mesopleuron smooth and centrally glabrous ( Fig. 3 ). Propodeum with anterior and posterior transverse carinae absent, anterior 0.5 of median longitudinal carina absent; anterior 0.3–0.5 smooth, posterior 0.5–0.7 with numerous more or less longitudinal rugulae on granulate surface ( Fig. 2 ). Tarsomere 4 of fore leg about 1.8 × as long as wide; hind leg ( Fig. 7 ) with tarsomere 2 about 1.1 × as long as tarsomere 5. Vein 3rs-m of fore wing spectral (and areolet superficially appearing open in many specimens). T1 1.3–1.5 × as long as apical width, appearing subpetiolate in dorsal view ( Fig. 2 ), smooth and shining; S1 about 0.2 × as long as T1 ( Fig. 7 ). T2 smooth and with widely scattered minute setiferous punctures medially and laterally (punctures separated by at least 1.0 × setal length), mediolaterally impunctate ( Fig. 4 ). Color. Black, the following yellow: mandible except for dark brown apex, gena immediately adjacent to mandible, labrum, clypeus, supraclypeal area, paraocular area (extending 0.6 × distance between antennal socket and apex of eye), ventral surfaces of scape and pedicel, ventral 0.5 of propleuron, ventral 0.7 of anterior edge and dorsal posterior corner of lateral area of pronotum, subalar ridge and immediately adjacent area of mesopleuron, tegula, apical 0.2 of T2, apical 0.4 of T3–4, apical 0.5–0.6 of T5, and following tergites. Flagellum with ventral surface light brown, dorsal surface dark brown. Legs with coxae, trochanters, and trochantelli white, except for diffuse light brown of basal 0.1 of hind coxa; femora, tibiae, and tarsi brownish-yellow. Pterostigma of fore wing light brown. Length. 3.4–3.7 mm (3.6 mm); fore wing 3.7–3.9 mm (3.8 mm).

Male. Structure. As in female, except flagellomeres 6–8 with elevated linear tyloids. Color. As in female, except: yellow of paraocular area extending to 0.8–0.9 × distance between antennal socket and apex of eye; ventral surface of flagellum brownish-yellow; lateral area of pronotum yellow but for brown stripe extending from median area to center of lateral area. Length. 3.1–3.5 mm; fore wing 2.9–3.2 mm.

Comments. In Fitton et al. (1982), the female of A. leucotrochi runs to couplet 9, where it founders due to the short antenna, and yellow supraclypeal area and paraocular area. In Kasparyan (1990), A. leucotrochi will go smoothly to couplet 56, which leads to A. brevicornis Holmgren and A. rufithorax Kasparyan. However , the combination of the length of flagellomere 4 and color patterns of the supraclypeal area, propleuron, and mesopleuron rules out placement in either species. Comparisons with determined material (including specimens used by Kasparyan) and published descriptions convince us that A. leucotrochi cannot be construed as belonging to any described species. It can be distinguished by the combination of: distinctly thickened flagellomeres 7–12, flagellomere 4 about 2.2 × as long as wide, color pattern of anterior head surface ( Fig. 5 ), regularly punctate mesoscutum (thus appearing evenly setose in pristine specimens), black mesopleuron and propodeum, length of S1 about 0.2 × length of T1, and smooth surface of T2. In particular, female A. leucotrochi differ from A. brevicornis , the closest species to it morphologically, in its completely yellow supraclypeal area, more extensively yellow portion of the gena immediately adjacent to the mandible, more extensive yellow markings on the propleuron and pronotum, and almost entirely yellow hind coxa (usually extensively brown in A. brevicornis ). In males, the pronotal and propleural coloration of the two species is more similar, but in A. leucotrochi the yellow paraocular area extends further dorsally (about 0.8 × the distance between the antennal socket and the apex of the eye, against 0.5 × in A. brevicornis ). In addition, A. brevicornis has a later flight period in Britain (June through July, possibly also August through September) and different hosts (found several times on an undetermined tenthredinid on Betula ).

Yellow to whitish apical banding is found on the tergites of many species of Adelognathus . In A. leucotrochi , the apical bands in tergites 3+ appear to be caused by a particularly thin epidermis, as they are often degraded to the point where a good portion of a band is missing in a mottled and irregular fashion.

Etymology. The specific name derives from that of the host, Nematus leucotrochus Hartig.

Figures

FIGURES 1–3. Adelognathus leucotrochi sp. n., ♀. 1. Habitus, lateral; 2. Mesosoma and first metasomal tergite, dorsal; 3. Mesosoma, lateral.

FIGURES 4–7. Adelognathus leucotrochi sp. n., ♀. 4. Metasomal tergites from second, dorsal; 5. Head, anterior; 6. Head and antenna, lateral; 7. Metasoma and hind leg, lateral.