Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters Author Scarparo, Giulia giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & marco. molfini @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 4561 - 7349 & luigi. caopinna @ uniroma 3. it; https: // orcid. org / 0000 - 0002 - 1152 - 258 X & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 & Laboratorio Interdipartimentale di Microscopia Elettronica (LIME), University Roma Tre, Rome, Italy. & giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 Author Wolton, Robert Locks Park Farm, Hatherleigh, Okehampton, Devon, EX 20 3 LZ, England. & robertwolton @ yahoo. co. uk; https: // orcid. org / 0000 - 0003 - 2892 - 569 X Author Molfini, Marco giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & marco. molfini @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 4561 - 7349 & luigi. caopinna @ uniroma 3. it; https: // orcid. org / 0000 - 0002 - 1152 - 258 X & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 Author Pinna, Luigi Cao giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & marco. molfini @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 4561 - 7349 & luigi. caopinna @ uniroma 3. it; https: // orcid. org / 0000 - 0002 - 1152 - 258 X & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 Author Ulio, Andrea Di Gi- giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & marco. molfini @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 4561 - 7349 & luigi. caopinna @ uniroma 3. it; https: // orcid. org / 0000 - 0002 - 1152 - 258 X & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 & Laboratorio Interdipartimentale di Microscopia Elettronica (LIME), University Roma Tre, Rome, Italy. & giulia. scarparo @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 3664 - 5698 & * andrea. digiulio @ uniroma 3. it; https: // orcid. org / 0000 - 0003 - 0508 - 0751 text Zootaxa 2020 2020-06-09 4789 2 348 370 journal article 21268 10.11646/zootaxa.4789.2.2 728d1add-05f4-4b24-bd7d-095bf90b84f6 1175-5326 3990836 CA98993F-C948-4506-A319-E9D20C8D4E2D Immature stages of Microdon devius Third instar larva Figs 7–9 Body width = 7.2 ± 0.6 mm ; body length = 9.4 ± 0.9 mm (n = 10). Dorsal reticulation. Dorsal reticulation extended over the whole dorsal body surface. Each process resembling a sea anemone, being divided into a smooth, columnar trunk topped by a brush composed by 20–30 long, flexible filaments ( Fig. 7F ). Posterior spiracular tubercle. Longer than wide, subquadrate in dorsal view, concave medially, bulged sub–basally; distance between spiracular holes 1.8 times as long as their diameter ( Figs 8E, F ). The base of posterior spiracular tubercle encircled by a smooth cuticular crown ( Figs 8E, F ). Spiracular plates flattened to slightly concave, of variable shape, separated by a broad and deep midsagittal cleft. Marginal band. Processes on the marginal band apparently without basal articulated joints ( Figs 9E, F ). Processes on the marginal band of three types : type one long and single, apically fringed; type two short and bifurcate, apically 2–lobed; type three composed by two type one flanking a cluster of three spiniform setae ( Figs 9E, F ). FIGURE 8 . Posterior spiracular tubercle of third instar larvae of M. myrmicae (A, B), M. analis (C, D), M. devius (E, F) and M. mutabilis (G, H); left, anterior view; right, apical view. A–H = 500 µm. ReFis, respiratory fissures; RH, respiratory hole; SC, smooth crown. FIGURE 9 . Marginal band of third instar larvae of M. myrmicae (A, B), M. analis (C, D) and M. devius (E, F); left, dorsal view; right, detail of marginal band. A = 500 µm; B, E = 300 µm; C = 100 µm; D = 50 µm; F = 200 µm. Puparium Figs 10 , 11 Body width = 7.3 ± 0.4 mm ; body length = 9.7 ± 0.5 mm (n = 10). Anterior spiracular tubercles . Length of each tubercle 2.25 times as long as wide and strongly curved ( Fig. 11F ), subcylindrical, slender, somewhat pointed at the apex, entirely furrowed by about 180 respiratory fissures ( Figs 10E, F ). Each fissure laying on a small papilla ( Fig. 10F ).