Myrmeleon bore (Tjeder, 1941)

(Figs. 5D, 6D, 29)

The first observations of the larva of this antion predate the species description (Schenck 1877; Dewitz 1882) while the first actual description dates back to almost a century later (Friheden 1973). It was redescribed by Matsura (1987) and Nicoli Aldini (2007), who compared it with closely related species. This species is finally treated in some monographic volumes (Gepp & Hölzel 1989; Gepp 2010; Krivokhatsky 2011).

Examined specimens. Germany. Mecklenburg Vorpommern, Graal Müritz, VI.2011 (C. Kehlmaier), 3 L3.

Italy. Lombardy, Pieve Albignola (Pavia), Cascinotto Mensa, IX.1979 (R. Nicoli Aldini), 2 L3. Lombardy, Casterno (Milano), Ticino River, V.2012 (D. Piccolino), 1 L3.

Description of 3 rd instar larva. Size (based on 6 specimens): BL 8.31 mm; HL 2.06 mm (1.90–2.20), HW 1.74 mm (1.61–1.84), ML 2.25 mm (2.13–2.34), HW/HL 0.84, ML/HL 1.09. General colouring pale brown mottled with dark brown, ventrally very pale with dark brown spots; dorsal side of the head capsule with large markings on the clypeo-labrum and posterior V-shaped marking, lateral sides of the head with dark markings, ventral side of the head pale with a pair of median dark spots (Figs. 5D, 29c); mandibles pale brown with a dark apex; legs pale; setae of the body black. Head longer than wide; mandibles slightly longer than the head capsule (Fig. 29a); interdental mandibular setae: (~5)(2–3)(2–3)(1); ventral side of the mandible with few setae at the base; labial palpi 3-articulated (Figs. 5D, 29b). IX abdominal sternite with sparse ventral digging setae, followed by an anterior row of digging setae and two sessile rastra each bearing 4 bristles (Figs. 6D, 29d).

Bio-ecology. M. bore lives in fresh environments and it is absent from areas influenced by a Mediterranean climate. M. bore is associated with sandy biotopes such as coastal dunes, river banks and internal sand deposits. The pits are built in exposed conditions, although the first stages are often found in proximity of vegetation.

Distribution. Widespread in the Palaearctic, from western Europe eastward to Japan.

Remarks. The larva of M. bore is the only known European antlion with 3 palpomeres. This species is similar to M. inconspicuus and to the non sympatric M. mariaemathildae in overall morphology; it is differentiated by the larger dimensions and the relative proportions of the mandibles and the head capsule.