Trypoxylon tuberantennatum Fu & Li, 2024

Fu, Yan, Li, Qiang & Ma, Li, 2024, Two new species of Trypoxylon Latreille, 1796 from China (Hymenoptera: Crabronidae), Zoological Systematics 49 (4), pp. 309-319 : 312-314

Trypoxylon tuberantennatum Fu & Li , sp. nov. (Fig. 2)

Diagnosis. The new species shares similarities with T. chosenense by the laminar dilation of free margin of clypeus and supraantennal tubercle, but differs from the latter by the following characters: metasomal petiole slender (GL/W = 3.5), and sides of petiole almost parallel medially; punctures on mesoscutum not stacked (PIS≈PD); slope from dorsal area to posterior area of propodeum small, lateral area narrow; body size slim and small; male flagellomeres II–VI with tyloids (vs. metasomal petiole thick and short (GL/W= 2.7), and sides of petiole not parallel medially; punctures on mesoscutum superimposed (PIS ≤ PD); slope from dorsal area to posterior area of propodeum large, lateral area broad; body size robust and larger; male flagellomeres II–VI without tyloids).

Description. Female (Fig. 2A). Body length 6.0–8.0 mm. Labial palpi, maxillary palpi, mandible mostly, free margin Figure 2. Trypoxylon tuberantennatum Fu & Li , sp. nov., female (A, C, F–G, J, L) and male (B, D–E, H–I, K, M–Q). A–B. Habitus, lateral view; C–D. Head, frontal view; E. Male antenna, lateral view; F, H. Pronotal collar and mesoscutum, dorsal view; G, I. Propodeum, dorsal view; J–K. Mesosoma, lateral view; L–M. Metasomal terga I–III, dorsal view; N. Male sternum VIII; O–Q. Male genitalia, ventral, dorsal and lateral view. Scale bar = 0.5 mm.

of clypeus, fore tarsus, mid tarsus I and most of pronotal lobe yellowish brown; tegula, mid tarsis II–V and posterior margin of pronotal collar dark brown; wings hyaline, veins and pterostigma brown. Body covered with short and silvery setae, length shorter than Od, seta on clypeus, lower frons and gena dense and appressed.

Head (Fig. 2C). Head rounded in frontal view, HW: HL = 10: 9. Mandible simple. Clypeus nearly flat, with fine dense punctures; lateral margin of clypeus slightly concave; free margin of clypeus with narrow and short protrusion, and slightly incised in middle. Supraclypeal area broad and short, length approximately equal to its maximum apical width; supraantennal tubercle low tuberiform, with apical transverse carina reaching outer top of antennal socket rim, intercepting supraantennal furrow. F I = AW × 3.0, F I: F II: F III = 3: 2: 2. Frons microscopically coriaceous, with fine, dense punctures (PIS ≈ PD), frontal furrow obvious. Inner eye orbits weakly convergent below, eye incision moderately broad and rather shallow (IODs = 10: 8). Vertex slightly convex, ocellar triangle flattened (OOD: Od: POD = 1: 3: 3). Gena narrow, evenly convex.

Mesosoma (Figs 2F–G, J). Pronotal collar narrow medially and enlarged towards sides, without minute tubercle in middle, anterior margin of collar rounded (Fig. 2F); pronotal lobes rounded. Mesoscutum, scutellum and metanotum microscopically coriaceous, with fine, dense punctures (PIS ≈ PD). Mesopleuron and metapleuron microscopically coriaceous, without puncture. Dorsal area of propodeum without U-shaped groove, without mid furrow, dorsum of propodeum entirely covered with oblique rugae (Fig. 2G). Posterior surface of propodeum with deep mid groove. Propodeal lateral carina well-developed; propodeal side dull, with feeble striations anteriorly (Fig. 2J).

Wings. In fore wing, R1 short, R1 = TCV × 0.5, CV1 = CV2 × 4.0, TCV = CV2, TCV straight.

Metasoma (Fig. 2L). Metasomal petiole club-shaped, about 3.5 × as long as posterior width in dorsal, approximately equal to metasomal terga II–III combined, P: Ma: 2(Ma): 3(Ma) = 39: 11: 21: 21.

Male (Figs 2B, D–E, H–I, K, M–Q). Body length 5.7–7.6 mm, similar to female externally, except: clypeus less produced anteriorly (Fig. 2D); flagellomeres II–VI beneath with tyloids, last flagellomere gradually narrowing from base to apex, slightly curved apically (Fig. 2E); eye incision more broadly and shallowly than female. Measurements: HW: HL = 10: 8.2; F I = AW × 2.4, F I: F II: F III = 6: 5: 5; F XI = BW × 1.7, F X ＜ F XI ＜ F IX–X; IODs = 10: 8.7, OOD: Od: POD = 2: 5: 6; R1 = TCV × 0.2, CV1 = CV2 × 3.5, TCV = CV2, TCV straight; P: Ma: 2(Ma): 3(Ma) = 33: 11: 18: 18; sternum VIII (Fig. 2N); genitalia (Figs 2O–Q).

Material examined. Holotype ♀, China, Zhejiang Province, Ningbo City, Hangzhou Bay National Wetland Park , 30°18′57″N, 121°9′14″E, 4 m, 19.Ⅰ Ⅴ.2011, coll. Yiping Wang ( ZAFU). Paratypes. 50♀ 39♂, same data as holotype except, 14.Ⅰ Ⅹ.2010 (3♀), 8.Ⅹ.2010 (16♀), 5.Ⅹ Ⅰ.2010 (18♀), 5.Ⅹ ⅠⅠ.2010 (1♀), 21.Ⅴ.2011 (1♀), 25. Ⅴ ⅠⅠ.2011 (4♀), 8.Ⅹ.2010 (22♂), 5.Ⅹ ⅠⅠ.2010 (12♂), 29. Ⅴ Ⅰ.2011 (1♂), yellow pan trap; 23. Ⅴ Ⅰ.2011 (7♀), 15. Ⅴ ⅠⅠⅠ.2010 (1♂), 14.Ⅰ Ⅹ.2010 (2♂), 21.Ⅴ.2011 (1♂), sweep net .

Distribution. China (Zhejiang).

Etymology. The specific name is derived from two Latin words: tuber - (= tubercular) and - antennatum (= antenna), referring to the flagellomeres II–VI beneath with tyloids.