Dacnusa (Pachysema) heterodentatus, Zheng, Min-Lin & Chen, Jia-Hua, 2017

Zheng, Min-Lin & Chen, Jia-Hua, 2017, A new species and three newly recorded species of the dacnusine genus Dacnusa Haliday (Hymenoptera: Braconidae: Alysiinae) from China, Zootaxa 4232 (4), pp. 511-522 : 518-520

Dacnusa (Pachysema) heterodentatus , sp. nov.

(Figure D)

Type material. Holotype: female: Migang peak, Liupan mountain, Ningxia Province, China, 22.viii. 2001, coll. Quanxiu Shi . Paratypes: 5 females and 2 males, same data as holotype ( FAFU) coll. Qinge Ji, Guanghong Liang, Quanxiu Shi and Jianquan Yang .

Description. Holotype, female. Body 2.7 mm long.

Head. Antenna with 28 flagellomeres, first flagellomere 1.3 times as long as second flagellomere, second and third flagellomere equal in length, first and penultimate flagellomeres 3.2 and 2.2 times as long as wide, respectively (Figs D9,10); in dorsal view of head (Fig. D2), 2.4 times as broad as long; eye 1.3 times as long as temple; temples and vertex distinctly setose; a fine crenulate groove place longitudinally on the mid area from vertex to occipitalia?OOL: OD: POL=26:10:13; eyes 1.4 times as high as broad; face (Fig. D1) weakly punctuate and densely setose all over, its width 1.7 times its median height; clypeus (Fig. D1) wide, smooth, glabrous and distinctly protrude on its lower edge; mandible (Fig. D3) with 3 teeth, first tooth rather small and only form a weak FIGURE D (1–10) Dacnusa (Pachysema) heterodentatus , sp. nov., ♀, holotype. 1. head (frontal view); 2. head (dorsal view); 3. mandible; 4. mesosoma (lateral aspect); 5. mesosoma (dorsal aspect); 6. propodeum and first tergite (dorsal aspect); 7. hind leg; 8. fore wing; 9. antenna (terminal five flagellomeres); 10. antenna (scapus, pedicellus, 1st–3rd flagellomeres).

protrusion, tooth 2 and 3 obviously larger than tooth 1, tooth 2 nearly an equilateral triangle, tooth 3 subsemicircular; maxillary palp rather long, distinctly reaching to mid coxa.

Mesosoma. In lateral view length of mesosoma 1.3 times its height; pronotum without a pronope, sides of pronotum smooth and glabrous; mesoscutum (Fig. D5) densely pubescent all over; notaulus developed, extend to the posterior part of mesoscutum, finely crenulate; medio-posterior depression of mesoscutum slender, nearly present on whole mesoscutum, finely crenulate; scutellum smooth and sparsely setose except its posterior end densely setose; mesopleuron shiny, largely smooth and glabrous; precoxal sulcus visible as a smooth groove, about 0.5 time as long as mesopleuron; propodeum (Fig. D6) with somewhat dense pubescence, although the fine rugosity on its shining surface is clearly visible; surface of metapleuron glossy and finely punctulate, with somewhat dense pubescence directed towards hind coxa (Fig. D4).

Wings. Pterostigma of fore wing nearly as long as vein 1-R1; marginal cell rather long; vein SR1+3-SR almost reaching top of fore wing and distinctly curved on its hind half; vein m-cu almost interstitial (Fig. D8).

Legs. Hind femur 4.5 times as long as broad distally; hind tibia 1.4 times as long as hind tarsus; third hind tarsomere 0.7 time as long as its telotarsus (Fig. D7).

Metasoma. First tergite (Fig. D6) beyond spiracles parallel-sided, 2.1 times as long as its apical width, covering with fine longitudinal striation all over and almost hairless (only several setae on its posterior part); tergites beyond first one polished; second and third fused and equal in length, combined length of tergites 2–3 1.3 times the length of first tergite, border between them indistinct; ovipositor sheath in lateral view about 0.5 time as long as hind tarsomeres 1–3 combined.

Colour. Head mainly dark brown; scapus of antenna yellow and remainder of antennal segments yellowish brown; mandibles yellow except its marginal part dark brown; palpi pale yellow; clypeus reddish yellow. Mesosoma dark brown; wings subhyaline, pterostigma and veins reddish yellow; legs mainly yellow, hind tibias and tarsus brown. First tergite dark brown; remainding tergites of metasoma yellowish brown; ovipositor sheath yellowish brown with its tip darkening.

Variation. Body length 2.5–2.8 mm, antenna with 29–30 flagellomeres.

Male. Similar to female; body length 2.4–2.5 mm, antenna with 31–32 flagellomeres.

Biology. Unknown.

Etymology. The name is derived from the Latin words “hetero” (means “unusual”) and “dentatus” (for “tooth”) which refers to the unusual first tooth of mandible.

Distribution. Known only from the type locality in Ningxia (Northwest Palaearctic China)

Remarks. This new species is similar to Dacnusa (Pachysema) megastigma Tobias , but differs from the latter as follows: 1) first tooth of mandible almost absent (first tooth normal in D.(P.) megastigma ); 2) notauli developed, extend to the posterior part of mesoscutum (notauli undeveloped, only present on anterior half of mesoscutum in D.(P.) megastigma ); 3) medio-posterior depression of mesoscutum rather long, nearly present on entire mesoscutum (absent on the anterior half of the mesoscutum in D.(P.) megastigma ).