Myolepta obscura Becher, 1882

Ricarte, Antonio, Marcos-García, M Angeles, Pérez-Bañón, Celeste & Rotheray, Graham E., 2007, The early stages and breeding sites of four rare saproxylic hoverflies (Diptera: Syrphidae) from Spain, Journal of Natural History 41 (25 - 28), pp. 1717-1730 : 1725-1726

Myolepta obscura Becher

Puparium

Overall appearance. Short-tailed larva with mouthparts of the saprophagous type ( Rotheray and Gilbert 1999); sub-cylindrical in cross-section, truncate anteriorly, tapering posteriorly; prolegs bearing crochets present on mesothorax and first six abdominal segments; anal segment coated in papillae bearing tufts of setae; pupal spiracles tapered, not club-tipped and curved backwards; prp broad and black-brown.

Dimensions. Length 8.55 mm, range 8.42–8.67 mm; width 3.46 mm, range 3.17–3.75 mm (n 52).

Head skeleton. Similar in detail to M. difformis head skeleton ( Figure 9 ).

Anterior spiracles. Similar to M. difformis ( Figure 14 ); 0.08 mm long.

Prothorax. Anterior fold with setae not spicules.

Mesothorax. Prolegs present with two rows of crochets.

Abdomen. Vestiture varying in size from 0.04 to 0.09 mm, fine, pale brown setae except on the ventral surface, where pubescence is inconspicuous; anal segment coated in papillae with tufts of setae at their tips; first and second pairs of lappets indistinct but third pair of lappets conspicuous, 0.32 mm long; prolegs with two rows of crochets present on the first six abdominal segments.

Pupal spiracles (see M. difformis spiracles in Figure 15 ). Separated by a distance twice their length, 0.3 mm long, dark brown except yellow at apex, tapered and curved backwards with irregularly spaced, protruding, and rounded tubercles bearing three or four spiracular openings crowded at the apex of the dorsal surface; sculpture shiny but vaguely indicated dome-shaped projections at base.

Posterior respiratory process ( Figure 17 ). Length 1.96 mm, range 1.92–2 mm; width at transverse band: 0.3 (n 52); smooth, without sculpturing, blackish brown in colour, with an indistinct transverse band and each spiracular plate bearing three pairs of gently curved, spiracular openings, interspiracular setae consisting of three or four long and conspicuous setal branches and a pit between the dorsal and dorso-lateral interspiracular setae.

Material examined

Two puparia from larvae collected 25 February 2006, in a wet hole of an east-orientated, live F. angustifolia tree trunk, España, Ciudad Real, Cabañeros National Park , Fresneda de Gargantilla, two males emerged 15 March 2006 .

Figures

Figures 8, 9. Head skeletons in lateral view. (8) Mallota dusmeti. (9) Myolepta difformis. Scale bar: 1.2 mm.

Figures 14–17. Myolepta spp. SEMs. (14) M. difformis anterior spiracle. (15) M. difformis pupal spiracle in dorsal view. (16) M. difformis prp apical end showing laterally the spiracular plate and setae (notice the white patches, always coating extensively Myolepta species puparia). (17) M. obscura prp showing remains of the typical Myolepta white coating (dorsal view). Scale and other photo data are shown at the bottom of each figure.