Neria nigricornis
Identification: Head: Frons black with an orange strip next to the antennae. Antennae: scape, pedicel and flagellum yellow, the latter with darkened edges Thorax: Black & shining on the mesonotum, some pruinosity on the pleurae. Legs: Hind femur with one black ring
Size: 5-7 mm
Thorax black and shining above, but covered with pruinosity at the sides. Wings longer (than N. ephippium). Body-length 5-7 mm (Greve et al. 1991)
Distribution
Europe: Countries (published), online at Fauna Europaea, Occurrences at GBIF
Andersson, 1989: Head covered by white, more or less silvery pruinosity. Gena, face and less than anterior quarter of frons yellow. Posterior three-quarters of frons, vertex and occiput black. Median occipital sclerite irregularly depressed as in N. cibaria and C. commutata Occiput and postgena with long, pale hairs, some of the hairs closest to the median occipital sclerite brown. Head bristles black: 2-3 slender orb, 1 vte, 1 vti. Proboscis yellow with long white hairs. First and second antennal segments yellow; third antennal segment in male blackish, in female more distinctly black with inner, posteroventral corner yellow. Arista black, basally distinctly swollen, with short pubescence that is thicker and longer in female. Thorax black with thick silvery white pruinosity, except on most parts of the mesonotum, which is glossy black. Hairs white, bristles black. Bristles: 2 npl, 1 sa, 1 pa, 1 posterior dc and one pair of sc, all strong and subequal. Acrostical hairs anteriorly in a double row, posteriorly changing into a simple row. Dorsocentral hairs in one irregular row. Stray hairs present on npl and along margin of mesonotum. Mpl and stpl with hairs, stpl in posterior part also with some longer, pale, bristle-like hairs. Legs yellow, f3 apically with dark ring, f2 apicaily with less distinct dark ring. Wings of normal Compsobata-type, faintly yellowish with yellow veins. Abdomen black with pale hairs, shiny except first tergite and a narrow, basal band on the second tergite, which are thinly pruinose. Female ovipositor sheath black, straight. Male genitalia relatively small, hypopygium shiny black (Fig. 1). Sternites 2-4 simple, narrow, longer than broad. Sternite 5 transformed into posteriorly directed forceps which are slender, incurved and dilated at apex. Sternite 6 is longer than broad, basally with an elevated, transverse, sharp ridge followed by two more indistinct such ridges and apically at right with a short serrated ridge, and apically emarginated. Surstyli bifide
Key: (Ozerov, 1987)
- 1 Hind femora with two black rings C. nitens
- Hind femora without rings or only with one black ring 2
- 2 The forehead is mostly black 3
- Most of the forehead is red-yellow 5
- 3 3rd antennal segment yellow, sometimes darkened at anterior margin. The pronotum is completely in a gray deposit or with 4 small bright-black spots 4
- 3rd antennal segment completely black. The large mid-back surface is brilliantly black C. helleni (comb. n.)
- 4 The black rings on the top of the hind femora are very weak, they are absent on the middle thighs. the dorsal surface of the middle thighs is usually very dark. 1 npl. Aristal bases black C. borealis sp. n. (f unknown)
- The black rings on the tops of the middle and hind femora are distinct. The dorsal surface of the middle thighs is not darkened. 2 npl. Aristal bases yellow C. nigricornis
- 5 Pleurae predominantly yellow 6
- Pleurae predominantly black, in a gray raid 7
- 6 The back of the head in the middle (see on the side) with a red-yellow patch. The middle face is completely black, in a gray raid C. dentigera
- Occiput in the middle part without a red-yellow spot. Middle of face red-yellow, with a black longitudinal stripe C. schumanni (f unknown)
- 7 Episterns of the prothorax in small hairs in addition to the long hairs on the bottom edge C. femoralis
- The epistels of the prothorax are bare, excluding several long hairs along the lower edge 8
- 8 Propleura, pteropleurae and humeral tubercles yellow C. silvicola
- Propleura and pteropleurae are darkened, more often black 9
- 9 VI sternum abdomen of the male with lamellar processes at the anterior edge. VII tergite of female abdomen squeezed from sides at base C. japonica
- Anterior margin and the abdominal sternite of the male is flat, without outgrowths. The female tergite of the female abdomen is compressed laterally in the middle. 10
- 10 The length of the hairs in the lower part of the sternopleura is much larger (in males) or equal (in females) to the length of the 2nd segment of the fore legs C. cibaria
(my translation)
Red List (Norway): Neria nigricornis is only known from one location in Norway (FI: Kautokeino, Avzi). The location is a flower bed with a large variety of flowers. The species is only known from Sweden, Finland and Russia, as well as Norway, here too rare. However, we do not have enough knowledge about the biology, habitat requirements and threat factors of this species to be able to make a satisfactory red list assessment. There is great uncertainty about the category's correct category ranking, and no categories from CR through LC can be omitted. The species is entered in category DD.