Neuroleon microstenus (McLachlan, 1898)

(Fig. 16)

The 1 st instar larva of this species was firstly described by Gepp (1974), while the other stages were investigated only recently by Devetak et al. (2010). See also under N. nemausiensis.

Examined specimens. Italy. Liguria, Bordighera (Imperia), Monte Nero, rock crevices, VIII.2010 (D. Badano), 2 L3, identification by biomolecular analysis; same locality, VIII.2012, 2 L3.

Description of 3 rd instar larva. Size (based on 4 specimens): BL 8.00 mm; HL 2.24 mm (1.81–2.51), HW 1.72 mm (1.57–1.82), ML 1.96 mm (1.90–2.10), HW/HL 0.77, ML/HL 0.87. General colouring light ochre with contrasting dark brown markings, ventral side pale with a dark pattern; head capsule with extensive dark markings, head dorsal side with a median pair of large dark markings creating a filled “V”, lateral sides completely dark (Fig. 16b), ventral side of the head dark brown with darker markings surrounding the gula (in one specimen the markings of the lateral sides prosecute ventrally) (Fig. 16d); labial palpi black (Fig. 16e); mandibles dark brown; legs pale; setae of the body black. Head longer than wide; dorsal side of the head capsule covered with sparse and very short dolichasters (Fig. 16c); mandibles almost as long as the head capsule (Fig. 16a); distance between the base of the mandible and basal tooth slightly smaller than that between the basal and apical teeth; interdental mandibular setae: (3–4)(1)(1)(0). Mesothoracic spiracles ochre. IX abdominal sternite with rastra equipped with 4 digging setae, internal seta shorter than the others (Fig. 16f).

Bio-ecology. A poorly known species, N. microstenus is usually reported for open Mediterranean environments, especially arid rocky scrublands. The larvae were collected at the base of shrubs and in rock crevices filled with sand.

Distribution. Widespread in the Mediterranean basin, notably lacking in the Iberian Peninsula.

Remarks. Besides the body colouring and the dark pattern of the head, N. microstenus is recognizable by means of the sparse short dolichasters covering the dorsal side of the head capsule. Another diagnostic character of this species is the dark colour of the ventral side of the head capsule, while in the other members of the genus it is normally pale.