Myrmeleon inconspicuus Rambur, 1842

Badano, Davide & Pantaleoni, Roberto Antonio, 2014, The larvae of European Myrmeleontidae (Neuroptera), Zootaxa 3762 (1), pp. 1-71 : 57-60

Myrmeleon inconspicuus Rambur, 1842

( Figs. 5E , 6E , 30 )

The larva of this species was described for the first time by Redtenbacher (1883, 1884), as Myrmeleon erberi Brauer, 1868 . The better existing description of this antlion is undoubtedly the masterly study of Principi (1943), detailing its morphology, ecology and behaviour. The larva of M. inconspicuus has been redescribed in several occasions mainly for identification purposes ( Steffan 1975; Hölzel & Gepp 1989; Nicoli Aldini 2007; Gepp 2010; Krivokhatsky 2011).

Examined specimens. Italy. Val d’Aosta, Aymavilles (Aosta), Pont d’Ael , rock overhang, VIII.2011 (D. Badano), 1 L3 laboratory-reared to adult. Veneto, Venezia (Venezia), Punta Sabbioni, III.2012 (E. Ruzzier), 7 L3. Campania, Castelcivita (Salerno), Calore River , VII.2010 (C. Labriola), 2 L3. Sardinia, Alghero (SS), Porticciolo, sand beach, III.2010 (D. Badano), 1 L3. Sardinia, Alghero (Sassari), Lazzaretto, sand beach, X.2010 (D. Badano), 1 L3 ; same locality, III.2011 (D. Badano) 5 L3. Sardinia, Sorso (Sassari), Platamona, coastal dune, VIII.2012 (D. Badano), 3 L3. Sicily, Gurne dell’Alcantara (Messina), VII.2010 (A. Corso), 5 L3 . Greece. Corfu, Korission lake, coastal dune, V.2012 (D. Badano), 1 L3. Corfu, Agia Varvara V.2012 (D. Badano), 1 L3 laboratory-reared to adult . Romania. Dobruja, Agigea, VIII.2010 (C. Manci), 1 L3. Dobruja, Badabag , VIII.2010 (C. Manci), 1 L3 . Tunisia. Gammarth , VII.2010 (local collector), 5 L3 .

Description of 3 rd instar larva. Size (based on 35 specimens): BL 8.08 mm; HL 1.70 mm (1.52–1.92), HW 1.48 mm (1.38–1.65), ML 1.67 mm (1.33–1.85), HW/HL 0.87, ML/HL 0.98. General colouring greyish ochre with a dark brown pattern, ventrally paler with dark brown markings; dorsal side of the head capsule with large dark markings on the clypeo-labrum, lateral sides of the head with dark markings, ventral side of the head pale with a pair of dark spots ( Figs. 5E , 30b ;); mandibles pale brown; legs pale; setae of the body black. Head slightly longer than wide; mandibles as long as the head capsule ( Fig. 30a ); interdental mandibular setae: (~5)(2–3)(2–3)(1); dorsal side of the mandible covered by few short setae disposed toward the margins, ventral side with few isolated setae at the base. IX abdominal sternite with irregularly disposed digging setae on the ventral side, followed by a row composed by at least 5 equal-sized digging setae, rastra each bearing 4 digging setae of which the external ones are the longest ( Figs. 6E , 30c ).

Bio-ecology. A relatively euryoecious species, M. inconspicuus is associated with sandy environments such as coastal dunes, sub-deserts, internal sand deposits and banks of watercourses, besides it also colonizes other microhabitat with presence of loose substratum such as dry open woods or grasslands. The larvae build their pits in exposed conditions, often in proximity of vegetation such as at the base of trees growing on back dunes. M. inconspicuus is often the most common pit-building antlion on coastal sand dunes, colonizing both open dunes than back dunes with a complex vegetation, despite in the southern coasts of the Mediterranean it is replaced by more termophilous species in exposed conditions.

Distribution. Widespread in the western Palaearctic region.

Remarks. The larva M. inconspicuus resembles other congeners with which it is often syntopic such as M. bore and especially the closely related M. mariaemathildae . This species is mainly recognizable thanks to pigmentation and disposition of digging setae on the IX abdominal sternite. According to Krivokhatsky (2011), the larva of the similar M. immanis Walker, 1853 is differentiated by the shape of markings on the clypeo-labrum.

Figures

FIGURE 5. Head of 3rd instar larvae of Myrmeleontini, ventral view; A, Myrmeleon formicarius; B, Myrmeleon gerlindae; C, Myrmeleon punicanus; D, Myrmeleon bore; E, Myrmeleon inconspicuus; F, Myrmeleon mariaemathildae; G, Myrmeleon hyalinus; H, Myrmeleon fasciatus; I, Euroleon nostras.

FIGURE 6. IX abdominal sternite of 3rd instar larvae of Myrmeleontini, ventral view; A, Myrmeleon gerlindae; B, Myrmeleon punicanus; C, Myrmeleon formicarius; D, Myrmeleon bore; E, Myrmeleon inconspicuus; F, Myrmeleon mariaemathildae; G, Myrmeleon hyalinus; H, Myrmeleon fasciatus; I, Euroleon nostras. Scale bar: 1 mm.

FIGURE 30. Myrmeleon inconspicuus Rambur, 1842, 3rd instar larva (Italy: Veneto, Venezia, Punta Sabbioni). Dorsal (above), ventral (middle) and lateral (below) view; a–c: diagnostic characters, see species description.