Dendroleon pantherinus (Fabricius, 1787)

Badano, Davide & Pantaleoni, Roberto Antonio, 2014, The larvae of European Myrmeleontidae (Neuroptera), Zootaxa 3762 (1), pp. 1-71 : 16-18

Dendroleon pantherinus (Fabricius, 1787)

( Figs. 3A , 4A , 8 )

The larva of this species was exhaustively described only once by Brauer (1867), as later accounts ( Hagen 1873; Redtenbacher, 1884) are based on this study. Afterwards only few records about the finding of the larva exist ( Roubal 1936; Kelner-Pillault 1967; Steinmann 1967). Gepp & Hölzel (1989) and Gepp (2010) reported the occasional synanthropy of this species and some behavioural traits.

Examined specimen. Italy. Emilia Romagna, Castel d’Aiano ( Bologna ), tree hole on chestnut, III.2012 (L. Colacurcio), 1 L1 laboratory-reared to L3 .

Description of 3 rd instar larva. Size: BL 10.60 mm; HL 2.49 mm, HW 2.01 mm, ML 1.79 mm, HW/HL 0.81, ML/HL 0.72. General colouring very pale, whitish pink without contrasting markings; head capsule reddish brown, ocular tubercles black, lateral sides of the head darker, ventral side pale; mandibles reddish brown; legs pale; body covered by black setae and thinner whitish bristles. Head longer than wide, with small ocular tubercles ( Fig. 8b ); mandibles bent upward ( Fig. 8e ), shorter than the head capsule and armed with long teeth ( Fig. 8a ); interdental mandibular setae: (4)(1)(1)(0); few short setae are disposed on the external margin of the mandibles. Pronotum covered by black setae ( Fig. 4A ); thoracic setiferous processes prominent ( Fig. 8c ); mesonotum with a characteristic tuft of black hair-like setae holding detritus in live specimens ( Fig. 8f ). IX abdominal segment subconical in shape ( Fig. 8d ); IX abdominal sternite longer than wide, provided with long setae ( Fig. 3A ).

Bio-ecology. D. pantherinus is a poorly known species associated with temperate woods of broadleaves, apparently avoiding arid biotopes; in Italy this antlion is reported from the sea level to mountains thus appearing relatively adaptable. The larvae were collected on trees, in tree holes filled with dry detritus and under barks, moreover they are remarkably able to colonize human buildings in proximity of woods, where they hide in sheltered corners ( Gepp & Hölzel 1989; Gepp 2010). Brauer (1867) implied that the larvae could also be found in the soil of pine woods but it is probably a speculation not supported by actual findings. The presence of specimens in artificial structures suggests that, at least potentially, it is able to colonize different kinds of cavities in forested habitats or in their proximity. The larva is an extremely motionless ambush predator, normally staying completely burrowed and covering the body with debris.

Distribution. Europe (except the Iberian Peninsula) and Caucasus; Asian records refer to closely related species ( Krivokhatsky 2011).

Remarks. The larva of this species is unmistakeable and the only other European member of the tribe is Tricholeon relictus Hölzel & Monserrat, 2002 , distributed in southern Spain. Despite the larva of this species is unknown, the South African species of Tricholeon differ from Dendroleon in the development of thoracic setiferous processes and teeth ( Mansell 1988; Stange 2004).

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 8. Dendroleon pantherinus (Fabricius, 1787), 3rd instar larva (Italy: Emilia Romagna, Castel d’Aiano). Dorsal (above), ventral (middle) and lateral (below) view; a–f: diagnostic characters, see species description.