Microdon, Meigen, 1803

Scarparo, Giulia, Wolton, Robert, Molfini, Marco, Pinna, Luigi Cao & Ulio, Andrea Di Gi-, 2020, Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters, Zootaxa 4789 (2), pp. 348-370 : 364-365

Keys to immature stages of the European species of Microdon

First instar larvae

1 Body about 1.5 times as long as wide; posterior spiracular tubercle long (more than 1.5 times as long as wide at base); marginal band elongate, showing eight waves on each side...................................... M. myrmicae / M. mutabilis

- Body about two times as long as wide; posterior spiracular tubercle very short (wider than long at base); marginal band short, showing 10 waves on each side................................................................... M. analis

Puparia

1 Most of the dorsal surface of puparium smooth and bare, with reticulation reduced to a narrow, lateral belt.............. 2

- Dorsal surface of puparium completely covered by a dorsal reticulation.......................................... 3

2 Anterior spiracular tubercles conical, tapering at apex; anterior spiracular tubercles about 1.4 times as long as wide at base; each reticulation process composed of groups of umbrella-like structures................................... M. myrmicae

- Anterior spiracular tubercles dome-shaped, blunt at apex; anterior spiracular tubercles about 0.8 times as long as wide at base; each reticulation process composed of stringy, extended projections.................................... M. mutabilis

3 Meshes of the dorsal reticulation no broader than the basal diameter of the posterior spiracular tubercle; posterior spiracular tubercle wider than long; anterior spiracular tubercles straight................................................. 4

- Meshes of the dorsal reticulation two times as broad as the basal diameter of the posterior spiracular tubercle; posterior spiracular tubercle longer than wide; anterior spilacural tubercles laterally curved................................. M. devius

4 Anterior spiracular tubercles equal or more than two times as long as wide....................................... 5

- Anterior spiracular tubercles one time only as long as wide, or shorter than wide.............................. M. miki

5 Anterior spiracular tubercles nearly cylindrical, about three times as long as wide; posterior spiracular tubercle light-brown contrasting with the reddish-brown apical spiracular plates.............................................. M. analis

- Anterior spiracular tubercles clearly conical, about two times as long as wide; posterior spiracular tubercle uniformly reddishbrown....................................................................................... M. major