Sirex noctilio Fabricius, 1793

3.3.6. Sirex noctilio Fabricius, 1793

Figure 16 View Figure 16

Sirex noctilio Fabricius, 1793 , Entomologica systematica emendata et aucta. Vol. 2: 104–132. (original description)

Sirex melanocerus Thomson, 1871 , Hymenoptera Scandinaviae. 1: 328.

Paururus atlantidis Ghigi, 1909 , Sopra una nuova specie di Siricide delle Azore. 40 [1908] (3–4): 163–170.

Material examined.

2 ♀ 4 ♂ Dorbod County, Daqing , Heilongjiang, 2016-VI-30, Gao T leg. ; Hekuangjunde Forest Farm , Hegang, Heilongjiang, 2013-VII-25 ~ 26, Wang H leg. ; 4 ♀ Bamiantong Town , Mudanjiang, Heilongjiang, 2015-VIII-14, Wang ZG leg. ; 3 ♂ Yushu , Jilin, Sun XT leg. ; 3 ♀ Kangping , Shenyang, Liaoning, 2016-VI-25, Gao T leg. ; 3 ♀ Zhanggutai Town , Fuxin, Liaoning, 2016-VI-25, Gao T leg. ; 3 ♀ 4 ♂ Chengjiao Forest Farm , Chifeng City, Inner Mongolia, 2016-V-23, Gao T leg.

Diagnosis.

Females with brownish spot around cell 1 R 1 (Fig. 16 A View Figure 16 ); vein 3 A of forewings absent; antennae completely blackish (Fig. 3 K View Figure 3 ); legs largely yellowish (except coxae blackish); tarsal pad of metatarsomere 2 0.3–0.4 times as long as ventral length of tarsomere (Fig. 7 F View Figure 7 ). Males with antennae completely darkish (Fig. 3 L View Figure 3 ); abdomen segments I – II and VIII – IX blackish, III – VII yellowish (Fig. 9 O View Figure 9 ); hind femora reddish brown.

Female Description.

Color: Body, antennae and palpi black with dark blue or purple metallic reflections (Fig. 16 A View Figure 16 ). Coxae and apical tarsomeres blackish; femora (except basal part brownish), tibiae and tarsi light yellowish brown (In black forms with metafemur blackish). Forewings mostly clear but with brownish spot around cell 1 R 1. — Head: Genae with small pits about 3.0–9.0 pit diameters apart (Fig. 6 K View Figure 6 ), vertex and postocellar area with pits 1.0–8.0 pit diameters apart, each pit diameter about 0.1–0.2 times as lateral ocelli (Fig. 5 K View Figure 5 ). — Thorax: Mesoscutum with large and shallowly pits in median area, pits more or less tooth-like process behind and teeth rarely fused transversally, thus without distinct transverse ridges. Metatarsomere 2 in lateral view 2.9–3.5 times as long as height, length about 1.1–1.4 times tarsomeres 3 + 4; tarsal pad 0.3–0.4 times as long as ventral length of tarsomere (Fig. 7 F View Figure 7 ). Forewings vein 3 A absent. — Abdomen: Median basin of tergum IX with basal width 0.9–1.1 times as long as median length, maximum width about 1.1–1.3 times as long as median length, median length 0.5–0.7 times of cornus length. Cornus in dorsal view short, with edges in the basal half straight and slightly curved apically, its median length about 1.0–1.2 times as long as maximum width of abdomen at junction of terga IX and X. Sheath. Basal part about 1.0–1.3 times as long as length of apical section. Ovipositor. Pits near middle annuli (the area at base of apical section of sheath) 0.50–0.75 times as long as an annulus, pits slightly decreasing in size toward base (Fig. 10 F View Figure 10 ), 0.6–0.8 times as high as lancet height in lateral view, 1.4–2.0 times as long as pits height.

Male Description.

Color: Head, thorax, antenna and coxae black with dark blue metallic reflections (Fig. 16 C, D View Figure 16 ). For and middle legs with femora (except for basal part brown), tibiae and tarsi light yellowish brown; metatibia and metatarsus blackish (except metatarsomere 4 and basal part of metatarsomere 5 yellowish brown); basal part of metatibia with yellowish brown area about 2.0–3.0 times as long as minimum width of tibia (Fig. 8 F View Figure 8 ). Forewings light yellowish, with pale brownish hue slightly developed near outer margin. Abdomen with terga I – II and VIII (including sternum IX) blackish, while III – VII light yellowish brown (sometimes color of tergum III can be variable, from black with dark purple metallic reflections to yellowish brown) (Fig. 9 O View Figure 9 ). — Thorax: Metatibia 3.8–4.2 times as long as maximum width (Fig. 8 F View Figure 8 ). Metatarsomere 1 in lateral view 2.7–3.8 times as long as maximum height.

Distribution.

Mainly distributed in Northeast China: Heilongjiang; Jilin; Liaoning; Inner Mongolia.

Host.

P. sylvestris var. mongolica Litv.

Note.

Schiff et al. (2012) conducted a detailed discussion on the morphology, biology, and related taxonomic treatments of this species. Intriguingly, these authors also highlighted the presence of the black form. According to Schiff et al. (2012), the black form seems be rare and could be found in southern Europe only, and there are no intermediate color forms between the black form and other specimens of S. noctilio . In China, we have not yet collected the black form of males, but the black form of females was discovered with a very low proportion to the typical forms of approximately 1 / 1000.