Tasactes pilosus Lü & Zhang, 2025

Lü, Heyu & Zhang, Runzhi, 2025, Four new species of the genus Tasactes Faust, 1894 (Coleoptera, Curculionidae, Dryophthorinae) from China, ZooKeys 1256, pp. 141-161 : 141-161

Tasactes pilosus Lü & Zhang sp. nov.

Figs 7 , 8 Chinese common name: 毛杯象 [máo bēi xiàng ]

Material examined.

Holotype: ♂, labelled: printed: 西藏 林芝市 巴宜区 排龙乡 迫龙沟 [ Xīzàng, Línzhīshì, Bāyíqū, Páilóngxiāng , Pòlónggōu ] / D 2 / 30.02421°N, 95.00770°E / Alt. 1923 m / 2018. VIII. 3 / 周润 [ Zhōu Rùn] leg. // printed: IOZ (E) 1965698 . Paratype: 1 ♀, same data as holotype, except a printed label: IOZ (E) 1965699 .

Type locality.

Polong Gully, Pailong Township, Bayi District, Linzhi City, Xizang Autonomous Region, China.

Comparative diagnosis.

Tasactes pilosus sp. nov. resembles T. dudkoi but differs unequivocally in: (i) body smaller (length 4.20–4.40 mm vs 5.40–6.20 mm in T. dudkoi ); (ii) antennal scape shorter and stouter (l / w4.75 vs l / w 6.70 in T. dudkoi ); (iii) pronotum lacking median carina, whereas with weak median carina in T. dudkoi ; (iv) pronotum bearing median longitudinal pilose pustule, while the latter is absent in T. dudkoi (see Legalov 2021: fig. 1); (v) temones distinctly more slender than in T. dudkoi (see Legalov 2021: fig. 2).

Description.

( holotype, except female sternite 8 and genitalia).

Coloration (Fig. 7 A, B ). Body entirely black; antennal scape and funicle, and tarsomeres reddish brown.

Head (Fig. 7 C – E ). Forehead flat, slightly narrower than rostrum base width; eyes elongate-oval, distinctly separated ventrally; rostrum elongate ( Rl / Rw 5.16), longer than pronotum ( Rl / Pl 1.10), evenly curved in lateral view, from base to apical 1 / 6 with short pubescence, apex with dense punctures; antennae inserted at apical 1 / 3 of rostrum; scape long (l / w4.75), not reaching eyes, gradually widening from base to apex, apical 1 / 3 markedly widened; funicular segments 1 and 2 elongate, segment 2 funnel-shaped, segments 4–6 transverse; club subobconical (l / w1.66).

Pronotum (Fig. 7 F ). Longer than wide ( Pl / Pw 1.07), widest at middle, apical 1 / 8 distinctly constricted, sides rounded; disc slightly convex in lateral view, densely covered with coarse punctures, punctures sparser on disc than laterally; dense, short pubescence forming median longitudinal pilose pustule; postocular lobes weak.

Scutellum. Small, subtriangular.

Elytra. Longer than wide ( El / Ew 1.27), widest at basal 1 / 4, apical 1 / 6 distinctly constricted, sides rounded; disc nearly flat in lateral view; interstriae convex, subequal in width, with dense short pubescence, interstriae 1–8 bearing interrupted longitudinal pilose pustules, pustule width subequal to interstrial width; striae deep, punctures large, bearing dense, short pubescence; distance between punctures exceeding puncture diameter.

Abdomen (Fig. 7 G ). Abdominal ventrites densely covered with coarse punctures; ventrite 2 with anterior margin slightly convex at middle, posterior margins of ventrites 2–4 rectilinear; ventrite 2 0.8 times length of ventrite 1, ventrite 3 slightly longer than ventrite 4, ventrite 5 2.0 times as wide as long.

Legs. Densely covered with short pubescence; femora and tibiae with punctures; procoxae subconical, contiguous; profemur more robust than mesofemur and metafemur, femora unarmed; profemur 3.3 times as long as wide; tibiae bearing single long uncus; protibia 6.2 times as long as wide; tarsi long, tarsomeres 1–3 obconical, ventrally with setae, onychium elongate; claws free, divergent; protarsomere 1 1.8 times as long as wide, tarsomere 2 1.3 times, tarsomere 3 1.4 times, onychium 4.3 times.

Male genitalia (Fig. 7 H – K ). Pedon 0.2 times length of temones, curved in lateral view, sides curved, base symmetrical, apex broad and not narrowed; temones slender, slightly curved; manubrium of tegmen very robust, elongate, apex curved, approximately 3.0 times as wide as temones; spiculum gastrale robust, evenly curved; basal plate bifurcate, basal arms opposed, upper part of each basal arm approximately triangular, length subequal to width, apices with rounded angles.

Female sternite 8 and genitalia (Fig. 8 G – I ). Sternite 8 with apodeme 0.8 times length of lamina; lamina bifurcate at base, sides curved, apex with sparse setae; gonocoxites cylindrical, apices with dense setae; styli short, cylindrical, width approximately 1 / 4 width of gonocoxite apices, apices with short setae; spermatheca with curved, apically rounded cornu; corpus robust; ramus and collum weakly developed.

Variation.

Male holotype. Measurements (in mm): Bl: 4.20. Rl: 1.65, Rw: 0.32. Pl: 1.50, Pw: 1.40. El: 2.42, Ew ( Bw): 1.90.

Female paratype. Measurements (in mm): Bl: 4.40. Rl: 1.60, Rw: 0.35. Pl: 1.51, Pw: 1.45. El: 2.61, Ew ( Bw): 1.98. Illustrations of a female are provided (Fig. 8 A – I ).

Female rostrum smooth and shiny from middle to apex, while male rostrum smooth only at apex; female antennae inserted at middle of rostrum, whereas male antennae inserted at apical 1 / 3.

Distribution.

Known only from the type locality in Xizang, China (Fig. 9 ).

Etymology.

The specific name is derived from the Latin word pilosus (hairy), referring to the dense pubescence on the pronotum, particularly the distinct longitudinal tuft of pubescence medially. Adjective, variable.

Key to species of the genus Tasactes

Figures

Figure 3. Tasactes baoxingensis sp. nov., holotype male. A. Dorsal habitus; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Eyes, ventral view; F. Pronotum, dorsal view; G. Ventrites, ventral view; H. Penis, lateral view; I. Penis, ventral view; J. Penis at apex, showing details of the pedon; K. Spiculum gastrale. Scale bars: 1 mm (A – D, F, G); 0.5 mm (H, I, K).

Figure 4. Tasactes baoxingensis sp. nov., paratype female (IOZ (E) 1965701). A. Dorsal habitus; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Pronotum, dorsal view; F. Ventrites, ventral view; G. Sternite 8; H. Ovipositor; I. Spermatheca. Scale bars: 1 mm (A – F); 0.25 mm (G – I).

Figure 5. Tasactes ocellatus sp. nov., holotype male. A. Habitus dorsal; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Eyes, ventral view; F. Pronotum, dorsal view; G. Ventrites, ventral view; H. Penis, lateral view; I. Penis, ventral view; J. Penis at apex, showing details of the pedon; K. Spiculum gastrale. Scale bars: 1 mm (A – D, F, G); 0.5 mm (H, I, K).

Figure 6. Tasactes ocellatus sp. nov., paratype female (IOZ (E) 1965696). A. Dorsal habitus; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Pronotum, dorsal view; F. Ventrites, ventral view; G. Sternite 8; H. Ovipositor; I. Spermatheca. Scale bars: 1 mm (A – F); 0.25 mm (G – I).

Figure 7. Tasactes pilosus sp. nov., holotype male. A. Dorsal habitus; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Eyes, ventral view; F. Pronotum, dorsal view; G. Ventrites, ventral view; H. Penis, lateral view; I. Penis, ventral view; J. Penis at apex, showing details of the pedon; K. Spiculum gastrale. Scale bars: 1 mm (A – D, F, G); 0.5 mm (H, I, K).

Figure 8. Tasactes pilosus sp. nov., paratype female (IOZ (E) 1965699). A. Dorsal habitus; B. Lateral habitus; C. Head, dorsal view; D. Head, lateral view; E. Pronotum, dorsal view; F. Ventrites, ventral view; G. Sternite 8; H. Ovipositor; I. Spermatheca. Scale bars: 1 mm (A – F); 0.25 mm (G – I).

Figure 9. Distribution of Tasactes species in China (based on specimens examined in this study).