Megistopus flavicornis (Rossi, 1790)

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

Megistopus flavicornis (Rossi, 1790)

( Fig. 18 )

As the older reports actually refers to other species ( Redtenbacher, 1884), the first description of the larva of M. flavicornis was realized by Steffan (1965). Later Cesaroni et al. (2010) redescribed exhaustively the larva of this species comparing it with the closely related Gymnocnemia variegata .

Examined specimens. France. Gard, Pompignan , dry stream sand deposits, VIII.2011 (D. Badano) , 2 L2, 2 L3 laboratory-reared to adults. Gard, Beauvoisin , pinewood on internal sand dune, VIII.2011, (D. Badano) , 1 L2, 2 L3 laboratory-reared to adults. Italy. Sardinia, Alghero ( Sassari ), pinewood on coastal dune, IV.2008 (C. Cesaroni) , 4 L3; same locality, XI.2008 , 2 L3. Greece. Chalkidiki , Mount Athos, VIII.2008 (L. Fancello) , 1 L3.

Description of 3 rd instar larva. Size (based on 7 specimens): BL 10.25 mm; HL 2.35 mm (2.07–2.41), HW 1.75 mm (1.60–2.05), ML 2.16 mm (2.07–2.28), HW/HL 0.74, ML/HL 0.92. General colouring light brown, mottled with dark, ventral side pale with a dark pattern; head capsule with extensive dorsal dark markings, ocular tubercles black, ventral side of the head pale with the exception of dark markings surrounding the gula; mandibles reddish brown; legs pale; setae of the body black. Head longer than wide; anterior margin of the clypeo-labrum covered by black dolichasters ( Fig. 18b ); mandibles as long as the head capsule ( Fig. 18a ); interdental mandibular setae: (3–4)(1)(1)(0); labial palpi covered by black dolichasters ( Fig. 18f ). Pronotum thickly covered by black setae ( Fig. 18d ); mesothoracic spiracles raised on over-developed tubercles, considerably longer than the mesothoracic setiferous processes ( Fig. 18c ); thoracic setiferous processes pedunculated. Abdominal spiracles pedunculated and prominent, clearly visible from above ( Fig. 18e ); VIII abdominal sternite provided with reduced odontoid processes; IX sternite pale, without conspicuous lateral markings, rastra with the internal pair of setae less than a quarter of the others in size ( Fig. 18g ).

Bio-ecology. M. flavicornis is a relatively euryoecious species, reported for Mediterranean-like environments characterized by the presence of sand-like substratum such as coastal dunes, internal sandy deposits and river banks. The larvae are usually found in shaded conditions such as at the base of trees or in proximity of other shelters.

Distribution. Widespread in the Mediterranean basin, reaching Austria and Hungary in the north and Iran in the east.

Remarks. This antlion is distinguished by extremely developed spiracles, an unusual and rare character in the whole family Myrmeleontidae , therefore considered worth of generic value by Stange (2004). Nevertheless the discovery of the larva of M. lucasi , in which these structures are not overdeveloped, allows to consider this character as exclusive of M. flavicornis . Therefore, the larvae of the genus Megistopus differs from the closely related Gymnocnemia only in details of the mandibles and of the abdominal IX sternite.

Figures

FIGURE 18. Megistopus flavicornis (Rossi, 1790), 3rd instar larva (Italy: Sardinia, Alghero). Dorsal (above), ventral (middle) and lateral (below) view; a–g: diagnostic characters, see species description. (photo by C. Cesaroni).