Chelonus frontalis
authorTobias & Lozan 2006
synonyms
body
shapeBody length: 2.6mm [TL4].
colorBody black
head
shapeSpecifically abrupt ventrally, face deepened posteriorly. In dorsal view big and subcubital, roundly widened behind eyes, 1.3 times as broad as long (45 : 35), a little broader than mesosoma. In frontal view looking broadened, 1.4 times as broad as high. Ocelli small, not widely separated, POL = 1.5 times OOL. Temples 1.5 times as long as eye [TL4].
sculptureHead behind eye and face transversely striate. Frons with concentrical sculpture. Clypeus largely faintly punctate and shining [TL4].
colorLabiomaxillary complex dark brown [TL4].
antenna
shape ♀Antennae [16 segments] almost as long as head and mesonotum combined; scape 2.5-3 times as long as wide; 3rd segment about 3 times as long as wide, apical segments 1.5 times as long as wide [TL4].
shape ♂
color
mesosoma
shapeIn dorsal view almost as broad as carapace. In lateral view 1.5 times as long as high and almost as long as length of carapace. Propodeum with faint transversal carina, lateral tubercles small. [TL4].
sculptureMesonotum rugose punctate. Scutum anteriorly granulate punctate, area before scutellum with pronounced coarse rugae. Propodeum granulate rugose [TL4].
color
legs
shapeFore and hind femora 3-3.5 times as long as broad. Hind tibiae 1.3 times longer than femora and 1.2 times as long as tarsi. Outer spur of hind tibiae longer than inner spur, almost reaching half of 1st metatarsal segment [TL4].
sculpture
colorFore coxae brown, hind coxae black; fore femora brown with yellowish apices, hind femora brown with slightly yellowish apices; fore tibiae yellowish, hind tibiae yellowish with brown belt at apices; all tarsi brown [TL4].
wings
shapeMarginal cell in forewing not large,1-R1 0.8 times of length of pterostigma. Second submarginal cell comparatively large, 1.3 times smaller than marginal cell. 3-SR almost 1.3 times as long as r, 3 times shorter than SR1 [TL4].
colorForewings slightly infuscate. Portions of costal vein brown, rest of vein, including pterostigma (except upwards) and R1 brownish and almost transparent [TL4]
metasoma
shapeCarapace oval, slightly incurved apicoventrally, 1.6 times as long as maximum breadth [TL4].
sculptureCarapace granulate with faint longitudinal and winding undulations spanning at most half its visible surface [TL4].
color
♀ ovipositorOvipositor hidden [TL4].
♂ aperture
other info
distributionCZ [FE].
remarksThis species is clearly distinguished from many others by its large and subcubital head and untypically deepened backward face [TL4].
hosts
type description
Microchelonus frontalis sp. n.
Female
Head. Specifically abrupt ventrally, face deepened posteriorly. In dorsal view big and subcubital, roundly widened behind eyes, 1.3 times as broad as long (45 : 35), a little broader than mesosoma. In frontal view looking broadened, 1.4 times as broad as high. Ocelli small, not widely separated, POL = 1.5 times OOL. Temples 1.5 times as long as LO. Antennae (14 segments present, tip missing) almost as long as head and mesonotum combined; scape 2.5-3 times as long as wide; 1st flagellar segment about 3 times as long as wide, apical segments 1.5 times as long as wide.
Mesosoma. In dorsal view almost as broad as carapace. In lateral view 1.5 times as long as high and almost as long as length of carapace.
Wings. Radial cell in forewing not large, its length along the metacarp 0.8 times of length of pterostigma. Second radio-medial cell comparatively large, 1.3 times smaller than radial cell. Second radial abscissa almost 1.3 times as long as first abscissa, 3 times shorter than third abscissa.
Legs. Fore and hind femora 3-3.5 times as long as broad. Hind tibiae 1.3 times longer than femora and 1.2 times as long as tarsi. Outer spur of hind tibiae longer than inner spur, almost reaching half of 1st metatarsal segment.
Metasoma. Carapace oval, slightly incurved apicoventrally, 1.6 times as long as maximum breadth. Ovipositor hidden.
Sculpture. Head behind eye and face transversely striate. Frons with concentrical sculpture. Clypeus largely faintly punctate and shining. Mesonotum rugose punctate. Scutum anteriorly granulate punctate, area before scutellum with pronounced coarse rugae. Scutellum missing. Propodeum granulate rugose with faint transversal carina, lateral tubercles small. Carapace granulate with faint longitudinal and winding undulations spanning at maximum half its visible surface.
Colour. Body black. Labiomaxillary complex dark brown. Legs: fore coxae brown, hind coxae black; fore femora brown with yellowish apices, hind femora brown with slightly yellowish apices; fore tibiae yellowish, hind tibiae yellowish with brown belt at apices; all tarsi brown. Forewings slightly infiiscate. Portions of costal vein brown, rest of vein, including pterostigma (except upwards) and metacarpus brownish and almost transparent.
Body length: 2.6mm.
Male. Unknown.
Diagnostic. This species is clearly distinguished from many others by its large and subcubital head and untypically deepened backward face.
Taxonomic affinity and comparison. In some features it resembles M. zaitzevi Tobias, 1972, from Mongolia, but differing in smaller body length, specific shape of head, smoother sculpturing and thicker segments of flagellum.
Distribution. Czech Republic
Holotype: 1♀, ČR, Moravia, Brno, ix.1935 [“Chlla ♀”], leg. H [=Hoffer]
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): | (2.3) 2.3 - 2.9 (3) | (2.3) 2.3 - 2.9 (3) |
| number of antennal segments: | 16 | --- |
| head, dorsal view |
| Head width : length | --- | --- |
| Temples narrowing - widening | parallel, widening | parallel, widening |
| Eye length : temple length | <= 0.75, 0.75 - 1.0 | <= 0.75, 0.75 - 1.0 |
| Roundness temple | strong, medium | strong, medium |
| POL : OD | 3 - 4 | 3 - 4 |
| Ocellar triangle shape | very narrow | very narrow |
| Excavation of head | 15 - 25% | 15 - 25% |
| head, lateral view |
| Head height : length | very short | very short |
| Eye height : length | short | short |
| Temple length : eye length | long | long |
| head, frontal view |
| Head width : height | wide, very wide | wide, very wide |
| Face width : height | very wide | very wide |
| Eyes converging ventrally | distinctly converging | distinctly converging |
| EH : MSL | very long | very long |
| Clypeus width : height | transverse | transverse |
| Clypeus extending above bottom of eyes | far above | far above |
| Tentorial pits | very large | very large |
| Shape of lower margin clypeus | convex, truncate | convex, truncate |
| antennae |
| Antennal shape | --- | filiform, not widened |
| Segment 3 length : width | medium | --- |
| Penultimate segment length : width | medium | --- |
| Length of antenna : length of body | 1: very short, 2: short | --- |
| mesosoma, lateral view |
| Length : height | medium | medium |
| transverse carina | weak, indistinct | weak, indistinct |
| lateral teeth | weak, small, short | weak, small, short |
| mesosoma, ventral view |
| Prepectal carina lamelliform | indistinct | indistinct |
| legs |
| Hind femur length : width ratio | short, medium | short, medium |
| Hind tibia length : hind tarsus length ratio | long | long |
| Hind tibia (longest) spur length : metatars length ratio | short, long | short, long |
| wings |
| Vein 1-R1 length : pterostigma length | medium, long | medium, long |
| Vein r length : vein 3-SR length | short | short |
| Shape vein SR1 (straight / concave / convex) | | |
| S-shape vein SR1 | --- | not S-shaped |
| cell M : cell Sm2 | Sm2 large | Sm2 large |
| Pterostigma length : width ratio | --- | --- |
| Angle between radial vein (r) : vein 1-R1 | --- | --- |
| metasoma, dorsal view |
| Length : width ratio of metasoma | short | short |
| Shape of metasoma | widest towards apex | widest towards apex |
| metasoma, lateral view |
| Length : height ratio of metasoma | medium | medium |
| posterior : anterior height ratio of metasoma | small, medium | small, medium |
| Position of maximum height | posterior | posterior |
| metasoma, ventral view |
| Metasoma posteriorly curved forwards | just/slightly incurved | just/slightly incurved |
| male apical aperture |
| Aperture width : metasoma width | no aperture | small, medium, large |
| Aperture shape | n. a. | (nearly) round, oval, elongate - slit |
| Median process shape | n. a. | --- |
| sculpture |
| head |
| general coarseness | medium | medium |
| clypeus |
| coarseness punctation | punctulate | punctulate |
| density punctation | --- | --- |
| face |
| sculpture type | striate | striate |
| sculpture direction | transverse | transverse |
| vertex and temple |
| sculpture type | striate (striolate) | striate (striolate) |
| mesonotum |
| sculpture type | --- | --- |
| scutellum |
| middle | --- | --- |
| lateral | --- | --- |
| metasoma |
| base - mid sculpture | longitudinally rugose / rugose-striate | longitudinally rugose / rugose-striate |
| sculpture at apex | rugulose | rugulose |
| coarse / fine boundary | base (to 50%) | base (to 50%) |
| color |
| head |
| mandibles color pattern | --- | --- |
| palpi, lightest color | black, dark brown | black, dark brown |
| 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 | medium dark | medium dark |
| fore femur lightest colour | medium light, light | medium light, light |
| fore femur color pattern | tip light | tip light |
| hind femur lightest colour | medium dark, medium light | medium dark, medium light |
| hind femur color pattern | tip light | tip light |
| hind tibia lightest colour | medium light | medium light |
| hind tibia color pattern | wide light base | wide light base |
| hind basitarsus lightest colour | medium dark | medium dark |
| hind tarsus segment 2-3 lightest colour | medium dark | medium dark |
| wings |
| middle veins lightest colour | medium dark | medium dark |
| basal veins lightest colour | medium dark, medium light | medium dark, medium 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. |
Chelonus frontalis in published keys
T14: Tobias, 2010
Palearctic species of Microchelonus Szépligeti (Hymenoptera: Braconidae, Cheloninae): key to species.
