Chelonus corvulus
authorMarshall, 1885
synonyms
body
shape♂ ♀ Length, 1 1/2 - 2 lin. (3.3 - 4.4 mm) [M]. 2.5 - 3.5mm [H2]. ♀♂: 3-6 mm, usually 3.5-4.5 mm [P2][T4], 5 - 6 mm [Te1].
colorBlack, Reticulate-rugose, dull [M].
head
shapeVertex transverse, contracted behind the eyes, cheeks not dilated; frontal fovea large, shallow, smoother than the rest of the head, geminated by a carina [M]. The head is roundly narrowed behind the eyes, its length. is equal to 0.5 of the width. The longitudinal diameter of the eye is about 2.5 times the height of the malar space [T13]. The head is transverse, slightly roundly narrowed posteriorly. The face is 2 times wider than the height; genae 2 times shorter than the longitudinal diameter of the head; temples equal to or slightly greater than the width of the head [eye?] [Te1]. Height of genae 1/3-2/5 longitudinal diameter of eye [T4]
sculptureHead more finely sculptured, orbits and cheeks striolated [M]. Clypeus shiny, finely and sparsely punctated [H2]. Temple and vertex finely and transversely striated with anastomosis (Fig. 3). Vertex with relatively fewer rugae (about 7-8) behind ocelli [T4]. Face and vertex behind ocelli with short, winding transverse rugae [T13]. Clypeus gently punctate, shining. Antennal fossa on the forehead transversely rugose [Te1].
colorPalpi and tips of the mandibles yellow-brown [M].
antenna
shape ♀24 - 26 segments, stouter, shorter than ♂, incrassated beyond the middle, and near the apex suddenly attenuated [M]. 25-28 segments, widened beyond the middle, shortest segments square [H2]. 24 - 29 segments [T13]. Antennae equal to the length of the head and mesosoma, filiform, compressed behind the middle, 24-27-segments [Te1].
shape ♂Antennae ♂ 27 segments, longer than the body [M]. As long as body [H2].
color
mesosoma
shapePropodeum short, transverse, truncate, bidentate, with 2 longitudinal carinae diverging posteriorly and sometimes obsolete [M]. Mesosoma length is 1.4 - 1.5 x height. Propodeum with transverse ridge and small lateral teeth. [T13]. Propodeum on the sides with sharp teeth, without clearly visible ridges [Te1].
sculptureMesosoma coarsely reticulated, especially near the scutellum, slightly shining, with an obsolete medial raised line, the sides and scutellum more finely rugulose [M]. Scutellum punctated [H2]. Mesonotum coarsely rugose-punctured, with sinuous longitudinal rugae before scutellum [T13]. The mesonotum and propodeum are roughly wrinkled. The scutellum is smooth in the middle [Te1].
color
legs
shapeLength hind femora 3.3 - 3.5 x width. Hind tarsi and tibia of equal length. Inner spur of hind tibia is 0.5 x length of metatarsus, length tarsus 5 is equal to length of tarsus 3. [T13]. Hind tibial spurs equal to 1/2 of the first tarsus segment [Te1].
sculptureHind coxae rugose [Te1].
colorFore femora at the apex broadly, the middle pair more narrowly, and all the tibiae yellow-brown; hind tibiae tipped with black and darkish near the base; tarsi dark, the 1st segment of the 4 posterior pale at the base ; spurs whitish [M]. Fore tarsi parttly pale [H2]. Legs are black; fore tibia entirely, middle and hind tibiae in middle and base of hind tarsus reddish white [Te1].
wings
shapeSR1 very slightly curved; radius of the hind wings sinuated. Wings 2 2/3 - 3 1/2 lin. (5.7 - 7.5) [M]. 1-R1 either as long as or just shorter than pterostigma [P2]. r is equal to 3-SR and to r-m. Sr1 curved 3 - 4 times as long as r. 1-R1 equal to pterostigma length. 1-CU1 = 0.16 times 2-CU1 [Te1].
colorWings infumated, stigma and veins dark, parastigma and basal veins brownish; tegulae black [M]. The wings are slightly smoky; tegulae and stigma are black, basal veins yellow [Te1].
metasoma
shapeMetasoma depresso-cylindrical, somewhat shorter than the head and mesosoma [M]. Carapace in dorsal view (Fig. 1) 1.9-2x as long as medially broad, relatively less broadening; in lateral view more or less posteriorly rounded (Fig. 2, see arrow) [P2]. Metasoma at apex noticeably curved (Fig. 4). Metasoma oval, its length. usually 1.7–1.8 times its width [T13]. Metasoma longer than mesosoma [Te1].
sculptureCovered with oblong subparallel reticulations, finer posteriorly, the apical third smoother and rather shining; at the base are 2 short carinae, subobsolete and confused with the other striae [M]. Base with coarse tortuous and anastomosing longitudinal rugae [T13]. Metasoma sharply longitudinally wrinkled in the basal half [Te1].
colorMetasoma immaculate [M].
♀ ovipositorOvipositor hidden [M]. The ovipositor is straight [Te1].
♂ apertureMetasoma ♂ imperforate [M].
other info
distributionBE, CH, CZ, GB, NL, PL [FE].
remarks
hosts
type description
6. Chelonus corvulus, n. s.
Chelonus annulipes, var. 1, Wesm., Nouv. Mém. Ac. Brux., 1838, p. 162 (antenna) 26—29-jointed).
Black, metasoma immaculate ; palpi and tips of the mandibles, fore femora at the apex broadly, the middle pair more narrowly, and all the tibiae testaceous; liind tibiae tipped with black and annulated with dusky near the base; tarsi fuscous, the 1st joint of the 4 posterior pale at the base ; calcaria whitish. Wings infumated, stigma and nervures fuscous, parastigma and basal nervures subtestaceous ; squamulae piceous ; 3d abscissa of the radius very slightly curved; radius of the hind wings sinuated. Reticulato-rugose, dull; head more finely sculptured, orbits and cheeks striolated ; vertex transverse, contracted behind the eyes, cheeks not dilated; frontal fovea large, shallow, smoother than the rest of the head, geminated by a carina. Antenna) ♂ 27-jointed, longer than the body; of the ♀ 24—26-jointed, stouter, shorter, incrassated beyond the middle, and near the apex suddenly attenuated. Mesosoma coarsely reticulated, especially near the scutellum, slightly shining, with an obsolete medial raised line, the sides and scutellum more finely rugulose. Metamesosoma short, transverse, truncate, coarsely reticulated, bidentate, with 2 longitudinal carinae diverging posteriorly and sometimes obsolete. Metasoma depresso-cylindrical, somewhat shorter than the head and mesosoma, covered with oblong subparallel reticulations, finer posteriorly, the apical third smoother and rather shining; at the base are 2 short carinae, subobsolete and confused with the other striae. metasoma ♂ imperforate. Terebra ♀ concealed. ♂ ♀. Length, 1 1/2—2; wings 2 2/3—3 1/2 lin.
Described from six males and four females. Common ; taken on Umbellifene in Leicestershire, and again near Barnstaple.
C. annulipes, Thoms., Opusc. Ent., vi., 1874, p. 572, ♀ agrees with this, so far as the description extends ; but the writer doubts whether his species be the same as Wesmael’s. Wesmael quotes annulatus, Nees, as a synonym, but doubtfully, because the latter has testaceous femora; in his Supplement he changes his mind, and thinks they may be the same, since H.-Schaffer (F. G., cliv., 23) describes the femora as sometimes black. Beinhard’s opinion has been already mentioned (see sp. 4). Wesmael also states that the males of his C. fenestratus belong to annnlipes, var. 1 (without pale spots on the metasoma). But fenestratus, Nees, Wesm., is made up of the sexes of two different species, and the name ought to be abandoned. Reinhard pronounces sulcatus, Nees, ♂ to be certainly the same as annulipes, Wesm. (but not necessarily its varieties); and fenestratus, Nees, probably the same as annnlatus, Nees. This is fortunately almost the last sample of the nomenclature of Chelonus we shall have occasion to give. The present insect is clearly not annulatus, Nees, nor annulipes, Wesm., but var. 1 of the latter, which seems a good species, and requires a name.
Data used in the multi-access key
These data are collected from the species descriptions and redescriptions, from published figures and photographs and from own measureements and observations. For a description of the different variables and value classes see this
pdf.
| morphology |
| basic information | female | male |
| body length (mm): | (3) 3 - 4.5 (6) | (3) 3 - 4.5 (6) |
| number of antennal segments: | 24 - 28 (29) | (26) 26 - 28 (29) |
| head, dorsal view |
| Head width : length | narrow, wide | narrow, wide |
| Temples narrowing - widening | parallel | parallel |
| Eye length : temple length | 1.0 - 1.25, > 1.25 | 1.0 - 1.25, > 1.25 |
| Roundness temple | strong, medium, weak | strong, medium, weak |
| POL : OD | 3 - 4, > 4 | 3 - 4, > 4 |
| Ocellar triangle shape | narrow | narrow |
| Excavation of head | 15 - 25%, 25 - 35% | 15 - 25%, 25 - 35% |
| head, lateral view |
| Head height : length | --- | --- |
| Eye height : length | --- | --- |
| Temple length : eye length | --- | --- |
| head, frontal view |
| Head width : height | --- | --- |
| Face width : height | wide | wide |
| Eyes converging ventrally | --- | --- |
| EH : MSL | short, long | short, long |
| Clypeus width : height | --- | --- |
| Clypeus extending above bottom of eyes | --- | --- |
| Tentorial pits | --- | --- |
| Shape of lower margin clypeus | --- | --- |
| antennae |
| Antennal shape | clearly widened | filiform, not widened |
| Segment 3 length : width | --- | --- |
| Penultimate segment length : width | --- | --- |
| Length of antenna : length of body | 2: short | 4: very long |
| mesosoma, lateral view |
| Length : height | short, medium | short, medium |
| transverse carina | weak, indistinct, present | weak, indistinct, present |
| lateral teeth | weak, small, short | weak, small, short |
| mesosoma, ventral view |
| Prepectal carina lamelliform | indistinct | indistinct |
| legs |
| Hind femur length : width ratio | medium | medium |
| Hind tibia length : hind tarsus length ratio | medium | medium |
| Hind tibia (longest) spur length : metatars length ratio | long | long |
| wings |
| Vein 1-R1 length : pterostigma length | long | long |
| Vein r length : vein 3-SR length | short | short |
| Shape vein SR1 (straight / concave / convex) | slightly concave, straight or S-shaped, slightly convex | slightly concave, straight or S-shaped, slightly convex |
| S-shape vein SR1 | --- | not S-shaped |
| cell M : cell Sm2 | --- | --- |
| Pterostigma length : width ratio | --- | --- |
| Angle between radial vein (r) : vein 1-R1 | --- | --- |
| metasoma, dorsal view |
| Length : width ratio of metasoma | short, medium, long | short, medium, long |
| Shape of metasoma | widest in middle, widest towards apex | widest in middle, widest towards apex |
| metasoma, lateral view |
| Length : height ratio of metasoma | short, medium | short, medium |
| posterior : anterior height ratio of metasoma | medium | medium |
| Position of maximum height | medium-posterior, posterior | posterior |
| metasoma, ventral view |
| Metasoma posteriorly curved forwards | just/slightly incurved | just/slightly incurved |
| male apical aperture |
| Aperture width : metasoma width | no aperture | no aperture |
| Aperture shape | n. a. | n. a. |
| Median process shape | n. a. | n. a. |
| sculpture |
| head |
| general coarseness | fine | fine |
| clypeus |
| coarseness punctation | punctulate | punctulate |
| density punctation | --- | --- |
| face |
| sculpture type | rugose | rugose |
| sculpture direction | transverse | transverse |
| vertex and temple |
| sculpture type | transverse rugulose | transverse rugulose |
| mesonotum |
| sculpture type | notauli slightly distinct | notauli slightly distinct |
| scutellum |
| middle | smooth | smooth |
| lateral | rugulose, rugose / striate | rugulose, rugose / striate |
| metasoma |
| base - mid sculpture | striate-rugose, longitudinally rugose / rugose-striate | striate-rugose, longitudinally rugose / rugose-striate |
| sculpture at apex | rugulose, smooth | rugulose, smooth |
| coarse / fine boundary | base (to 50%) | base (to 50%) |
| color |
| head |
| mandibles color pattern | light tip | light tip |
| palpi, lightest color | light brown, brownish yellow | light brown, brownish yellow |
| antennae |
| scapus, lightest color | black, dark brown | black, dark brown |
| segment 3 and 4, lightest color | black, dark brown | black, dark brown |
| legs |
| fore coxae lightest colour | dark | dark |
| fore femur lightest colour | medium light | medium light |
| fore femur color pattern | tip light, base dark | tip light, base dark |
| hind femur lightest colour | dark | dark |
| hind femur color pattern | entirely dark | entirely dark |
| hind tibia lightest colour | medium light | medium light |
| hind tibia color pattern | narrow light ring | narrow light ring |
| hind basitarsus lightest colour | medium light | medium light |
| hind tarsus segment 2-3 lightest colour | dark | dark |
| wings |
| middle veins lightest colour | dark, medium dark | dark, medium dark |
| basal veins lightest colour | medium light, light | medium light, light |
| metasoma |
| metasoma colour pattern | entirely dark | entirely dark |
| metasoma lightest colour | dark | dark |
| metasoma base, colour pattern | entirely dark | entirely dark |
| metasoma base, light spots | n.a. | n.a. |
| metasoma base, light band | n.a. | n.a. |
