Il y a une clef ici avec quelques précisions:
https://www.researchgate.net/publicatio ... _Syrphidae
=================
- Pleurae entirely dusted, dull. Bare, shining black median stripe on face narrow (Fig. 8a). Mesoscutum covered by long, woolly, upstanding hairs. Hind margin of
scutellum with hairs as long as two thirds / three quarters the median length of the
scutellum.
Occiput very broad, about as broad as distance between antennal pits and upper edge of facial knob (Fig. 6f). Antero-lateral surface of the hind femur with hairs about as long as the maximum width of the femur (dorsal view). Metasternum bare.
Hypandrium in lateral view with pointed inner process (Fig. 12fJ ............................................ obscura BECHER
- Pleurae shining, except for proepimeron and anterior part of mesanepisternum l. Bare, shining median stripe on face broadening from facial knob upwards to almost twice its width (Fig. 8b). Mesoscutum with hairs more or less reclined. Hind margin of
scutellum with hairs half as long as the median length of the
scutellum.
Occiput less broad, about half or two thirds of distance between antenna! pits and upper edgc of facial knob (Fig. 6i). Antero-lateral surface of the hind femur with hairs half as long as the maximum width of the femur (dorsal view). Metasternum hairy.
Hypandrium in lateral view with rounded inner process (Fig. 12i) ............................................................... vara (PA~ZER)
================
-> il y aussi la bande faciale qui a une forme bien différente entre les deux espèces, peut-être que cette image permet une comparaison même si ma vue de profil n'est pas l'idéal:
https://zenodo.org/api/iiif/v2/4f80fd69 ... efault.png
[Edit: la photo ci-dessus viens de là:
https://www.gbif.org/species/4516779/treatments (figure 5) - manquait la légende de la photo: A et B = Myolepta obscura, C et D = Myolepta vara]
Un autre article intéressant à propos de ce genre:
https://www.researchgate.net/publicatio ... _Syrphidae
Je viens d"éditer mon message précédant pour préciser que les larves vivent dans la matière organique des caries des vieux arbres plutôt que dans le bois.
Thierry
