Tenthredo megamaculata, Xiao & Niu & Wei, 2020

Xiao, Wei, Niu, Gengyun & Wei, Meicai, 2020, Two new species of the Tenthredo grahami group from China (Hymenoptera: Tenthredinidae), with a revised key to species, Zoological Systematics 45 (2), pp. 118-125 : 122-123

Tenthredo megamaculata sp. nov. ( Figs 1 C–D, 3)

Diagnosis. This new species is most similar to T. gulmargi Singh & Saini, 1987 from North India, but differs from the latter by the black spots on the 2nd to 8th abdominal tergites distinctly longer than half length of abdominal tergites, the 5th cypsella of lancet much shorter than 5th serrula, the male penis valve with narrow and long apical process, and the apex of parapenis almost truncate without inner process, while in T. gulmargi , the black spots on abdominal tergites about half length of the abdominal tergite, the 5th cypsella of lancet as long as 5th serrula, the male penis valve simple without apical process, and the apex of parapenis with a distinct inner process).

Description. Female. Body length 10.5–11.5mm ( Fig. 1C ). Body and legs light green in alive by yellow brown in dried; following parts black: median fovea and connected broad lateral stripes of frons and postocellar area, ocellar basin, a small middle spot on postocellar area ( Fig. 3B ), antenna except apex of first antennomere, a narrow transverse stripe on bottom of pronotum, a wide middle stripe on mesoscutal middle lobe, dorsum of mesoscutal lateral lobe, bottom of parapsides, basal 1/3 of 1st abdominal tergite, middle strongly constricted basal bands on dorsum of 2nd to 8th abdominal tergites ( Fig. 1C ), slightly curved vertical narrow stripe on mesepisternum ( Fig. 3D ), a dorsal narrow stripe on all legs from trochanter to tarsi; most hairs on upper 2/5 of hind orbit and dorsum of head, thorax and abdomen black, setae on sheath brown, most hairs on lateral and ventral side of body silver. Wings hyaline, pterostigma and vein C yellow green, other venation brownish.

Dorsal side of head ( Fig. 3B ) with fine but clear microsculpture, weakly shiny, microsculpture within black spots more distinct; mesonotum finely but densely sculptured, lateral lobe with sparse and minute punctures; anterior slope of mesoscutellum faintly microsculptured, posterior slope and lateral of appendage shallowly and sparsely punctured; upper half of mesopleuron finely microsculptured, shiny, ventral half sparsely punctured mixed with microsculpture; abdominal tergites finely sculptured, weakly shiny; sides of apical sheath with fine microsculpture, strongly shiny.

Hairs on dorsum of head straight and distinctly inclined forward, 0.8 times as long as diameter of lateral ocellus; length of hairs on mesonotum, mesoscutellum and mesopleuron about 0.5, 0.75 and 1 times diameter of lateral ocellus, respectively. Apex of labrum round; clypeus large and flat, distinctly broader than distance between eyes below, anterior margin narrowly and shallowly incised to a depth about 0.25 times length of clypeus, lateral lobe truncate ( Fig. 3A ); malar space equal to diameter of lateral ocellus; distance between lower corners of eye 0.9 times longest axis of eye; supraantennal tubercles strongly elevated, free-standing and slightly divergent backwards, height 1.1 times its width, length about 2 times its height and as long as postocellar area, distance between posterior ends of tubercles 1.2 times its breadth, posterior end abruptly cut off from frontal ridges, bottom of median fovea without carina; interocellar furrow deep and straight, postocellar furrow deep; postocellar area hardly elevated, about 1.4 times as broad as long, without middle carina or middle furrow, lateral furrows weakly curved, distinctly divergent backward; in dorsal view length of temple 0.5 times eye length, lateral sides distinctly curved and narrowed backward ( Fig. 3B ); occipital carina low but complete, lower part without fold. Antenna filiform, not compressed, about as long as head and thorax together, 3rd antennomere 1.5 times as long as 4th antennomere, 8th antennomere 2.5 times as long as broad ( Fig. 3I ). Mesoscutellum roundly elevated, without longitudinal carina or peak but with faint transversal ridge, mesoscutellar appendage with short longitudinal carina; distance between cenchri 2.2 times longest axis of a cenchrus; mesepisternum weakly elevated at middle, ventral thorn absent ( Fig. 3D ). Hind tibia 0.8 times as long as tarsus, inner tibial spur 0.55 times as long as basitarsus; basitarsus slender, 0.8 times as long as following 3 tarsomeres together; claw with a short and obtuse basal lobe, inner tooth distinctly shorter than outer tooth. Vein cu-a in forewing joining cell 1M at basal 0.35, cell 2Rs distinctly longer than cell 1Rs; hind anal cell sessile ( Fig. 1C ). Lancet narrow and long with 17 serrulae ( Fig. 3C ), serrulae distinctly oblique, middle serrulae each with 1 inner subbasal tooth and 11–13 distal subbasal teeth, annular sutures strongly oblique, annular spines bands very narrow, annular spines very short and sparse; 5 th to 7 th serrulae as in Figure 3H .

Male. Body length 8.5–9.5 mm ( Fig. 1D ). Body color and structure similar to female but hind coxa with narrow black dorsal and ventral stripes, malar space 0.5 times diameter of lateral ocellus, distance between eyes below about 0.7 times longest axis of eye, in dorsal view head shorter and distinctly narrowed, basal lobe of claw distinct; subgenital plate 1.2 times as long as broad, apex roundly and narrowly convex; harpe longer than broad, apex of parapenis almost truncate without inner process ( Fig. 3F ); penis valve broad with a long and narrow apical process ( Fig. 3G ).

Material examined. Holotype. ♀, China, Sichuan Province, Mt. Emei, Leidongping (29°55′N, 103°33′E; elev. 2350 m), 7 July 2009, Meicai Wei leg. Paratypes. 1♀, Sichuan Province, Mt. Emei, Leidongping (29°55′N, 103°33′E; elev. 2350 m), 7 July 2009, Meicai Wei leg. ; 2♀ 2♂, Sichuan Province, Mt. Emei, Leidongping (29°55′N, 103°33′E; elev. 2350 m), 8 July 2009, Meicai Wei leg. ; 1♀ 1♂, Sichuan Province, Mt. Emei, Leidongping (29°55′N, 103°33′E; elev. 2350 m), 8 July 2009, Gengyun Niu leg. ; 2♀ 3♂, Sichuan Province, Mt. Emei, Leidongping (29°55′N, 103°33′E; elev. 2350 m), 7 July 2009, Zejian Li leg. ; 1♀ 2♂, Sichuan Province, Mt. Emei, Jinding (29°31.37′N, 103°21.22′E; elev. 3073 m), 20 July 2011, Junzhe Xue & Hu Ping leg. ; 1♀, Tibet, Chaya County, G241 (30°42.59′N, 97°19.56′ E; elev. 3350 m), 24 June 2009, Zejian Li leg.

Distribution. China (Sichuan, Tibet).

Etymology: The specific epithet is composed of a Latin prefix mega- and maculata, referring to the abdomen with large black maculae.

Figures

Figure 1. Tenthredo spp., adults. A–B. T. nigrobullifera sp. nov. C–D. T. megamaculata, sp. nov. A, C. Female; B, D. Male. Scale bars=1.0mm.

Figure 3. Tenthredo megamaculata sp. nov. A. Female head, front view. B. Female head, dorsal view. C. Lancet. D. Mesopleuron and metapleuron, female. E. Apical segments of abdomen and ovipositor, lateral view. F. Gonoforcep. G. Penis valve. H. The 5th–7th serrulae. I. Female antenna.