Ancistrocerus sur Piekarski & Carpenter

Piekarski, Patrick K., Carpenter, James M. & Sharanowski, Barbara J., 2017, New species of Ancistrocerus (Vespidae, Eumeninae) from the Neotropics with a checklist and key to all species south of the Rio Grande, ZooKeys 718, pp. 139-154 : 140-143

Ancistrocerus sur Piekarski & Carpenter sp. n.

Material examined.

Holotype. Female, ARGENT: Jujuy Posta Lozano 15-17 Dec 1967 C.C. Porter. Allotype. Male, BOLIVIA: Tarija, V-7 1969 C. Porter. Paratypes. 9 females, 12 males.

Diagnosis.

This species can be distinguished from all other Neotropical Ancistrocerus using a combination of the following characters: sternum II lacking a longitudinal basomedian furrow; sternum II in lateral view strongly truncate posterior to transverse furrow (Fig. 2a); parategula broadly flattened (Fig. 3c); humeri with angular projection (Fig. 3c); T I with carina effaced dorsally (Fig. 3g); T II with punctation ending about one puncture diameter from apex (Fig. 4c); maculations reduced, on metasoma usually at most T II with a very narrow apical yellow band (Fig. 1a, b).

Description.

Female. Body length 11.50-14.00 mm. Color. Almost entirely black; small traces of yellow may be present at apex of clypeus; small yellow dot in antennocular space, interantennal space, and upper gena; usually have thin, ferruginous band at apex of T II-VI and sterna II-VI (Fig. 1b). Tarsi ferruginous (Fig. 1a).

Head. Twelve antennal articles; 1st flagellomere ~1/3 the size of scape; pedicel ~1/2 size of 1st flagellomere; vertex with pubescence as long as distance between posterior ocelli; vertex with dense coarse punctures, much less dense than on clypeus; vertex without tubercle; clypeus about as long as wide, narrowed apically with slight concavity at tip; mandibles decussate, four teeth spaced along the edge; mandibular ridges present; antennal sockets less than 1/2 socket diameter away from clypeus; palpal formula 6:4; maxillary palpomere two about same length as palpomere three; a narrow interantennal distance, approximately the diameter of a antennal socket; ocello-occipital distance greater than the length of the ocellar triangle; cephalic foveae closely spaced, set in a slight medial depression which is delimited posteriorly by a carina; dorsal occipital carina simple and complete, without fork, running to mandible; gena most wide dorsally.

Mesosoma. Long thoracic hairs (Fig. 1a); puncture density similar throughout (except tegula and anterior pronotal face); anterior pronotal face largely impunctate, and without paired medial foveae; lateral pronotal foveae present; pronotal carina weaker on dorsum; humeral carina absent, but sharp angular projection at the humeri (Fig. 3c); pretegular carina present; epicnemial carina absent; no apparent notaulices and parapsidal furrows; tegula without large punctures, appearing smooth; tegula tapered posteriorly, reaching slightly beyond the parategula; parategula broadly flattened (Fig. 3c); axillary fossa oval, broader than long; metonotum rounded and sloped; metanotum without tubercles; propodeum without complete dorsal carinae (Fig. 3g); propodeum without shelf and sloping posteroventrally; propodeal valvula rounded, and not free posteriorly. Wings. Prestigma less than half length of pterostigma; marginal cell distally rounded with small appendix; both recurrent veins received by second submarginal cell; basal angle of second submarginal cell acute; second submarginal cell not petiolate. Legs. One midtibial spur; bifid tarsal claws.

Metasoma. Thin white or yellowish hairs on metasoma, longest on T I; T I carina effaced dorsally (Fig. 3g); width of T1 at least twice as long as wide; T1 without apical lamella; T II with very thin apical lamella; T II with punctation ending about one puncture diameter from apex (Fig. 4c); T I and T II punctation equally dense, but T II punctures slightly smaller; apices of terga not more punctate than rest of terga; bottom of basal sulcus with longitudinal ridges; sternum II in lateral view strongly truncate posterior to transverse furrow (Fig. 2a); sternum II without basomedian longitudinal sulcus; sterna with similar puncture size and density as corresponding terga.

Male. Body length 10.00-13.00 mm. Color. Almost entirely black; clypeus usually entirely yellow (Fig. 5b); scape may be yellow ventrally; mandible may have yellow traces; small yellow dot present on upper gena but typically absent in antennocular and interantennal space; usually have ferruginous band at apex of T II-VII and sterna II-VII (Fig. 5b). Tarsi ferruginous.

Head. Identical to female, except for: 13 antennal articles; apex of antennae hooked; clypeus longer than wide, narrowed apically with slight concavity at tip; mandibles decussate, four (five on allotype) teeth spaced along the edge; cephalic foveae absent.

Mesosoma. Identical to female (Fig. 5a, b).

Metasoma. Identical to female, but 7 metasomal segments and male genitalia. T II apex in male not reflexed (cf. A. arista and A. similis ).

Distribution.

Argentina, Bolivia.

Etymology.

The name is the Spanish word for “south,” referring to its southerly distribution in the Neotropics. It is to be treated as a noun in apposition.

Key to the species of Ancistrocerus south of the Rio Grande