Libelloides longicornis (Linnaeus, 1764)

Badano, Davide & Pantaleoni, Roberto Antonio, 2014, The Larvae of European Ascalaphidae (Neuroptera), Zootaxa 3796 (2), pp. 287-319 : 308

Libelloides longicornis (Linnaeus, 1764)

( Figs. 3E , 12 )

The first description of the larva of this species was realized by Navás (1915) as the previous accounts were simply brief reports about the discovery of the eggs and 1 st instar larvae ( Ragonot 1878; McLachlan 1878) while other old descriptions were inconclusive ( Lacroix 1923; Rabaud 1927). Rousset (1973) redescribed the larvae, comparing them with congeners.

Examined specimens. France. Var , 17 L3 laboratory-reared from a female collected at Mt. Aurelien, VI.2011 (D. Badano) .

Description of 3 rd instar larva. Size (based on 17 specimens): BL 11.18 mm; HL 2.63 mm (2.49–2.77), HW 3.17 mm (2.91–3.42), ML 3.06 mm (2.77–3.34), HW/HL 1.20, ML/HL 1.16. General colouring grey with a darker grey pattern, dorsal side with a median paler area, ventral side pale mottled with dark grey; head capsule brown with a darker anterior portion, ventral side of the head brown with a darker area on the mouthparts and with a pair of distinctive longitudinal pale stripes ( Fig. 12c ), mandibles dark brown; legs with dark brown coxae and paler femora, tibiae and tarsi; setae of the body black. Head wider than long, noticeably dilated posteriorly ( Fig. 12b ); mandibles longer than the head capsule ( Fig. 12a ); interdental pseudo-teeth: (3–4)(1–3)(0–1); external margin of the mandible with short setae. Pronotum pale brown with indistinct brown stripes; mesothoracic spiracles ochre with a black apex. Abdominal spiracles dark brown; VIII abdominal sternite pale with the exception of the odontoid processes; IX sternite pale with a dark apex.

Bio-ecology. L. longicornis is a common and euryoecious species occurring in open environments such as: grasslands, pastures, glades and scrublands. In Italy this ascalaphid is mainly associated with mountainous biotopes and reports from lowlands are mainly attributable to stranded individuals ( Pantaleoni 1990 a, 1990b), while in southern France this species shows a remarkably wider altitudinal range and it is common in Mediterranean environments ( Puisségur 1967; Badano pers. obs.). The larvae are ambush predators living on the soil surface.

Distribution. Reported from Portugal, Spain, France, Switzerland, Italy and Germany.

Remarks. The larvae of L. longicornis are easily recognizable, with the exception of the Sicilian endemic L. siculus , thanks to the presence of longitudinal pale stripes running on the ventral side of the head. However L. longicornis and L. siculus are easily set apart for the different body colouring, besides the presence of L. longicornis in Sicily is unproven and unlikely ([Bernardi] Iori et al. 1995).

Figures

FIGURE 3. Chaetotaxy of the VIII abdominal sternite of 3rd instar larva of Ascalaphidae. A, Ascalaphus festivus; B, Bubopsis agrionoides; C, Puer maculatus; D, Deleproctophylla australis; E, Libelloides longicornis. Scale bar: 100 µm.

FIGURE 12. Libelloides longicornis (Linnaeus, 1764), 3rd instar larva (France: Var, Mt. Aurelien). Dorsal (above), ventral (middle) and lateral (below) view; a–c: diagnostic characters, see species description.