authorDahlbom, 1832

body

shape1 1/8 - 1 1/2 lin. [D]. ♀: 2.2 mm, ♂: 2.6 mm. [P6]. ♂ 2.6 - 3.0mm [T14]. ♂ 2.25 - 3.0mm [M2].

colorblack, finely coriaceous-punctate, fine silky pubescence [D].

head

shapeHead in dorsal view (Fig. 19) transverse, 2.0 - 2.1 x as broad as long, temple constricted and one-third shorter than eye. Ocelli small and round, POL : OD : OOL as 8 : 3 : 8. Eye in lateral view (Fig. 20) distinctly twice as high as wide, temple behind eye broader than eye. Malar space one-quarter longer than basal width of mandible. Face just less than twice as wide as high, inner margin of eyes parallel; clypeus clearly less wide than face, somewhat more than twice as wide as high; distance between tentorial pits one-third ionger than distance between pit and lowest margin of eye. Occiput weakly excavated [P6]. The head is roundly narrowed behind the eyes, its width is twice its length. POL equal to OOL and almost 3 times the diameter of the ocellus (8: 3). Malar space 1.3 times basal width of mandibles [T14].♂ Malar space 0.3-0.8 longitudinal eye diameter, palpi not elongated [T14, in key].

sculptureFace concentrically and upwards, head above (frons + vertex) rather transversely, temple and cheek rather longitudinally with dense rugulo-striation, dull; clypeus almost smooth and shiny [P6]. Head covered with a whitish down, very shiny [M2].

colorMandible yellowish brown, palpi brownish [P6]

shape ♀Antenna with 16 [in taxonomic remark 18] antennomeres, Third segment 2.5 times and penultimate segment 1.5 times as long as broad apically. in key: Third segment twice and penultimate segment 1.2 times as long as broad apically. [P6]. 3rd segment of antenna 2.5 times as long as wide, preapical segment 1.5 times [T14].

shape ♂Antenna shorter than body, as long as head, mesosoma and half carapace combined, with 18 - 20 segments. Third segment twice as long as broad apically. Further segments indistinctly shortening and attenuating so that penultimate segment 1.2 times as long as broad. in key: Third segment twice and penultimate segment 1.25 times as long as broad apically [P6].

mesosoma

shapeMesosoma in lateral view 1.45 times as long as high. Mesonotum in lateral view projecting anteriorly similar to that of M. microphthalmus Wesmael (Fig. 21, see arrow). Notauli distinct by somewhat roughened sculpture of mesonotum. Propodeum latero-medially with a pair of tubercules [P6]. Propodeum with small lateral tubercles [T14].

sculptureMesosoma rugose, propodeum on anterior or horizontal part roughly rugose and on its posterior or vertical part with carinae radiating around lunule [P6].

legs

shapeHind femur 3.7 - 3.8 times as long as broad medially. Hind tibia just longer than hind tarsus; pair of spurs of hind tibia almost equal in length, inner spur half as long as basitarsus. Hind basitarsus slightly longer than tarsomeres 2-3 [P6]. ♂: The inner spur of the hind tibia is noticeably shorter than half of the hind metatarsus [T14, in key].

colorBlack, with yellowish fore tibiae and tarsi, or black with yellow-brown tibiae and tarsi, with a black ring on the tip of the hind tibia [D]. Coxae and trochanters dark brown, hind femur brown, otherwise legs brownish with yellowish suffusion [P6]. Hind tibia dark brown, with a slight weak yellowish band or light brown patch in front of the middle [T14, in key].

wings

shapeFore wing one-fifth shorter than body. Pterostigma (Fig. 22) 2.2 - 2.3 times as long as wide, issuing radial vein distally from its middle, R1 just longer than pterostigma, 1-R1 0.8 times as long as pterostigma, r somewhat longer than 3-SR, SR1 straight and ending far before tip of wing [P6]. ♂: Vein SR1 of the fore wing is curved outward [T14]. ♂: The marginal cell is 1.5-2 times larger than the 2nd submarginal cell, 1-R1 is 1.5-3 times shorter than the pterostigma [T14, in key].

colorFine, pale veins. Wing with shifting rainbow colors [D]. Tegula dark brown to brown, wings subhyaline (or faintly fumous). Pterostigma opaque brownish, veins proximally opaque yellowish and distally brownish [P6].

metasoma

shapeSlender [D]. Carapace in dorsal view (Fig. 23) 1.7 - 1.8 times as long as broad medially, as long as mesosoma and half of head combined; in lateral view (Fig. 24) 2.5-2.6 times as long as high behind; in ventral view apically incurved (Fig. 25), i.e. ventral cavity somewhat shorter than carapace itself [P6]. ♂: Metasoma 1.6–1.7 times as long as wide [T14, in key].

sculptureCarapace longitudinally rugo-rugulose, sculpture weakening on its hind end; pair of keels distinct, short and converging (Fig. 23) [P6].

colorMetasoma black [T14, in key].

♀ ovipositorOvipositor sheath (in ventro-lateral view) as long as hind tarsomeres 1-3 [P6].

♂ apertureApical foramen elliptic, 2.2 times as wide as high (Fig. 26) [P6]. The apical aperture is located at the bottom of the posterior surface of the metasoma [T14]. The apical aperture is 3-3.5 times less wide than the metasoma [T14, in key].

other info

distributionDE, DK, SE [FE].

figures

references

links

photos

type description

Data used in the multi-access key

Chelonus nigritulus in published keys