Ammophila gracilis Lepeletier de Saint Fargeau, 1845

Buys, Sandor Christiano, 2020, Morphological studies on the last instar larvae of three South American species of Sphecidae (Hymenoptera: Apoidea), Zootaxa 4885 (2), pp. 259-265 : 260-261

Ammophila gracilis Lepeletier de Saint Fargeau, 1845

Last instar larva

( Figs 1–6 )

Head: Height 960 mm, width 910 mm. Coronal suture a well-developed line. Cephalic rugosity absent. Parietal bands light brown, 320 mm long, 25 mm wide. Antennal orbits light brown, circular, 63 mm in diameter. Cephalic concavities indistinct, no traces of pigmented areas defining these concavities were observed. Epistomal suture indistinct. Setae absent on top and sides of head. Base of genal area with about 10 small punctures; setae absent. Clypeal area with punctures (about 6 mm in diameter), and seven tenuous setae (about 5 mm long). Hypostoma, pleurostoma and anterior tentorial arms not pigmented.

Mouthparts: Labrum 420 mm wide; about 25–30 punctures concentrated on apical half; setae absent. Epipharynx with spines (up to 28 mm long), sparsely distributed on lateral, marginal, and median portion, spines on median portion facing to base of labrum; sensorial area with six basiconic sensilla (5 mm in diameter). Mandibles brown, darker in apical half and in external mandibular articulation; 410 mm long; with four teeth gradually larger towards apex; mandible in inner view wedge-shaped, curved inward apically, teeth semicircle aligned; with small denticles on median portion of external surface. Maxillae with few setae; brown areas absent; maxillary palpi 57 mm long and 38 mm wide; galea 75 mm long and 43 mm wide; lacinial area densely covered with spines. Labium 520 mm wide; small lateral areas brown; oral portion roughed; setae absent; labial palpi 50 mm long and 38 mm wide; labial projection of spinneret 480 mm wide.

Body: Greyish white. Length 9.5 mm, maximum width 4.5 mm (segments AV and AVI). Dorsiventrally flattened. Each segment divided in two annulets, posteriorly more prominent and continuous with pleural lobes on abdomen. Pleural lobes indistinct on thorax; prominent on abdomen, joined together forming a continuous margin. Integument with spines (up to 10 mm long), larger and more abundant on thorax, spines apically rounded on some areas, especially in segment AX. Spiracles internally ornamented with concentric annulets; spiracular depressions approximately circular, well defined on abdomen, absent on thorax; diameter: segment TI = 70 mm, segment TII = 63 mm, segments AI to AX = 85–95 mm.

Figures

FIGURE 1–2. Last instar larva of Ammophila gracilis. 1, labrum/epipharynx; 2, mandible, inner view.

FIGURES 3–6. Last instar larva of Ammophila gracilis (scanning electron microscopy). 3, epipharynx; 4, mandible, internal view; 5, mandible, external surface, detail showing denticles; 6, labium (S = sensilla, MA = mandibular articulation).