Megistopus lucasi (Navás, 1912)

Badano, Davide & Pantaleoni, Roberto Antonio, 2014, The larvae of European Myrmeleontidae (Neuroptera), Zootaxa 3762 (1), pp. 1-71 : 36-39

Megistopus lucasi (Navás, 1912)

( Figs. 3G , 4G , 19 )

The larva of this rare species is described for the first time.

Examined specimens. Italy. Sardinia, Arbus (Oristano), Torre dei Corsari , coastal sand dunes, V.2010 (D. Badano), 1 L3 and 1 L3 laboratory-reared to adult; same locality, IV.2011, 4 L3 and l L3 laboratory-reared to adult . Sardinia, Chia ( Cagliari ), beach, XI.2011 (D. Badano), 2 L3 and l L3 laboratory-reared to adult .

Description of 3 rd instar larva. Size (based on 7 specimens): BL 9.48 mm; HL 2.27 mm (2.15–2.49), HW 1.86 mm (1.71–1.96), ML 1.98 mm (1.90–2.22), HW/HL 0.74, ML/HL 0.92. General colouring ochre with pink shades and mottled with dark brown, ventral side very pale with dark markings; head capsule with dark occipital markings, lateral sides with dark markings, ocular tubercles black, ventral side of the head pale except the gular area; mandibles orange; legs pale; setae mostly black except some white bristles in anterior portion of the body. Head longer than wide; anterior margin of the labrum covered by white dolichasters ( Fig. 19c ); mandibles slender, slightly shorter than the head capsule ( Fig. 19a ), distance between the base of the mandible and basal tooth larger than that between the basal and apical teeth; interdental mandibular setae: (2)(1)(1)(0); labial palpi covered by whitish dolichasters ( Fig. 19e ). Pronotum covered by sparse setae, anterior setae paler in colour ( Figs. 4G , 19b ); mesothoracic spiracles cylindrical, raised on tubercle but comparatively stout, shorter than the first pair of setiferous processes ( Fig. 19d ); mesothoracic setiferous processes pedunculated. Abdominal spiracles slightly protruding, not visible from above; VIII sternite without odontoid processes; IX sternite with a pair of dark markings on the side; rastra short and equipped with 4 digging setae, internal seta less than a quarter of the others in size ( Figs. 3G , 19f ).

Bio-ecology. M. lucasi is a poorly known species exclusively reported for coastal sites characterized by the presence of well preserved sand dunes. The larvae were collected in proximity of isolated junipers on open dunes, buried at the base of junipers and among their roots. In these conditions, the substratum is always composed by clean sand, without conspicuous quantities of organic debris except juniper needles. They are apparently absent from back dunes with a more thick vegetation.

Distribution. This very rare species is known for few coastal localities in Sardinia, Tyrrhenian Italy, Algeria and Tunisia.

Remarks. The larva of M. lucasi is characterized by an unmistakable habitus reminding G. variegata , despite the two species are easily set apart by the shape of the mandibles and the different hue of the body.

Figures

FIGURE 3. IX and VIII abdominal sternite of 3rd instar larva of Dendroleontini and Nemoleontini. A, Dendroleon pantherinus; B, Nemoleon notatus; C, Distoleon tetragrammicus; D, Creoleon lugdunensis; E, Neuroleon assimilis; F, Macronemurus appendiculatus; G, Megistopus lucasi; H, Gymnocnemia variegata. Scale bar: 1 mm.

FIGURE 4. Pronotum of 3rd instar larvae of Dendroleontini and Nemoleontini; A, Dendroleon pantherinus; B, Nemoleon notatus; C, Distoleon tetragrammicus; D, Creoleon lugdunensis; E, Neuroleon nemausiensis; F, Macronemurus appendiculatus; G, Megistopus lucasi; H, Gymnocnemia variegata. Scale bar: 1 mm.

FIGURE 19. Megistopus lucasi (Navás, 1912), 3rd instar larva (Italy: Sardinia, Chia). Dorsal (above), ventral (middle) and lateral (below) view; a–f: diagnostic characters, see species description.