Symmorphus murarius (Linnaeus)

Tormos, José, Polidori, Carlo, Asís, Josep Daniel & Gayubo, S. F., 2008, Description of mature larvae of Allodynerus rossii (Lepeletier), Ancistrocerus auctus (Fabricius), Euodynerus dantici (Rossi) and Symmorphus murarius (Linnaeus) (Hymenoptera, Vespidae), Zootaxa 1946, pp. 42-54 : 48-50

Symmorphus murarius (Linnaeus)

( Figs. 28–31)

A nest of this species (length = 80 mm; diameter = 6 mm) was obtained from a trap-nest (number 465) placed in Ticino Regional Park (Riserva Orientata La Fagiana, Milano, Italy) in 2003. The nest had 3 cells 18 mm long on average, from one of which emerged a male (September 2003); two larvae were obtained from the other two cells. The nest lacked of the typical mud closing plug, revealing that it was not completely provisioned at the moment of removal.

Body ( Fig. 28) (l = 8.5 mm, w = 3 mm) fusiform, robust, with dorsum of thoracic and first 8 abdominal segments divided into two annulets by transverse crease ( Fig. 28, tc). Anus ( Fig. 28, a) as transverse slit. Pleural lobes weakly developed. Integument with setae ( Fig. 29, se, sed) (l = 10–15 µm), arranged in transverse band behind of the spiracles; 7–10 abdominal segments with scattered setae and sparse minute spinules on anterior margin of each segment. First two spiracles ( Fig. 28, 30) with subatrium (d = 180 µm) larger than atrium (d = 130 µm), and 1.2 times wider as successive ones (d = 110 µm); walls of atrium spinulose; opening into subatrium armed with spines.

Cranium ( Fig. 31) (w = 1.1 mm, h (excluding of labrum) = 0.6 mm), with setigerous punctures and scattered setae ( Fig. 31a) (l= 10–25 µm) more numerous near insertion of mandibles. Coronal suture and parietal bands present. Antennal orbits circular (d = 130 µm) with papilla ( Fig. 31b) (d = 50 µm) with 3 sensilla. Clypeus with scattered setae (l = 10–25 µm). Labrum ( Fig. 31c) (w = 550 µm) strongly bilobed, with 18 short conical sensilla (w = 5–10 µm) on each side. Epipharynx with 6 protuberant sensilla on distal edges of both sides.

Mouthparts. Mandibles (l = 500, w = 280 µm) tridentate, brown; tooth truncate apically. Maxillae ( Fig. 31d, m) truncate at apex, external surface with setae (l = 20–25 µm), upper surface of apical portion spinulose; maxillary palpi ( Fig. 31d, mp) (50 x 60 µm) with 2 apical sensilla (d = 8, 10 µm); galeae ( Fig. 31d, g) (20 x 50 µm). Labium (w = 240 µm) with short palpi ( Fig. 31d, lp) (50 µm x 60 µm), which have 4 apical sensilla; prementum with four setae (l = 15 µm) in area ventral to each palpus; salivar orifice ( Fig. 31d, so) as transverse slit (l = 280 µm) with strongly raised lips.