Key to the species of Chilosphex

1 Males .............................................................................................. 2

- Females............................................................................................ 3

2 Episternal sulcus ending at level of scrobe; medial emargination of S8 broad: 3.5 × as wide as lateral tooth (Fig. 3e); metasoma black............................................................................. Ch. argyrius (Brullé)

- Episternal sulcus extending to anteroventral margin of pleuron; medial emargination of S8 narrow: 1.5 × as wide as lateral tooth (Fig. 3f); metasoma basally reddish................................... Ch. pseudargyrius (Roth in de Beaumont)

3 Medial clypeal lobe slightly emarginate (Fig. 2a); scutum coarsely, densely micropunctate with scattered punctures (Fig. 3a); episternal sulcus ending at level of scrobe; metasoma reddish basally or entirely black............. Ch. argyrius (Brullé)

- Medial clypeal lobe distinctly emarginate (Fig. 2b); scutum finely, sparsely micropunctate with scattered punctures (Fig. 3b); episternal sulcus extending to anteroventral margin of pleuron; metasoma reddish basally............................................................................................ Ch. pseudargyrius (Roth in de Beaumont)

Genus Chilosphex Menke in Bohart and Menke, 1976

Chilosphex Menke in Bohart & Menke 1976:39, 128. Type species: Sphex argyrius Brullé, 1833 by original designation.

Diagnosis. The following characters are the main recognition features of Chilosphex: clypeus broad, flattened, its free margin in female emarginate and divided into three lobes; male antenna without placoids; second submarginal cell of forewing higher than broad; claws with two ventral teeth; female foreleg without well-defined tarsal rake; pectens of inner hindtibial spur coarse and well-spaced from each other; spiracle of T1 located in distal part of tergum; male S8 rectangular, with lateral teeth (Fig. 3e, f).

The following are the characters shared by both included species. Head. Clypeus, subantennal sclerite and paraocular area with dense appressed, silvery setae. Vertex, occiput and gena microsculptured, with scattered punctures and fine, sparse, inconspicuous, appressed, pale setae. Erect setae pale. Mesosoma . Mesopleuron, metapleuron and propodeum dull, obliquely areolate-rugose. Propodeal enclosure dull, transversely areolate-rugose. Erect setae of mesosoma pale. Wings moderately smoky; veins dark brown. Legs black, with black spines.

MALE. Head. Clypeus nearly trapeziform; medial lobe slightly elongate, not or slightly longer than lateral one, slightly emarginate apically; lateral lobe moderately defined; lateral emargination insignificant (Fig. 2c, d). Mandible and palpi black or dark brown. Mesosoma . Scutum slightly shiny, coarsely, densely micropunctate with scattered punctures. Metasoma. T1 with appressed, silvery setae posteriorly.

FEMALE. Head. Mandible brownish or reddish in basal half, black apically. Palpi dark brown.

Classifications. Both species were originally described in Sphex . Kohl (1890) and Roth (1963) assigned S. argyrius to the subgenus Palmodes Kohl, 1890, as did Roth (1967) for Sphex pseudargyrius . The absence of a foretarsal rake in the female and the short episternal sulcus of Sphex argyrius Brullé, 1833 allowed A. Menke in Bohart and Menke (1976) to transfer this species and S. pseudargyrius Roth, 1967 to the new genus Chilosphex (Bohart & Menke 1976) . Menke, however, did not realize that the episternal sulcus is long in Ch. pseudargyrius, he probably had not seen specimens.

Life history (Berland 1958; Bohart & Menke 1976; Kazenas 2001; Arens 2017). Females nest in cliffs, cracks in stones and rocks, in crevices and other cavities between stones and bricks in walls, and stone fences. The nest consists of one cell, the cavity of which is lined with stems of plants, collected on the ground near the nest and carried in the mandibles. Prey are bush crickets of the genera Pholidoptera Wesmaël, 1838 and Metrioptera Wesmaël, 1838 ( Orthoptera: Tettigoniidae), which are paralyzed and delivered to the nest on the ground in the amount of three or four per cell. The egg is laid to the side of the abdomen near the base of a hind leg.

Remarks. Morphologically, the genus is clearly different from the related genera Prionyx Vander Linden, 1827 and Palmodes Kohl, 1890 . It closely resembles Palmodes by the shape of the clypeus, the claws with two ventral teeth and by lacking placoids on the male antenna, but differs in the absence of a distinctly defined tarsal rake of the female foreleg and the rectangular male S8 with lateral teeth ( Palmodes has a defined tarsal rake on the female foreleg and male S8 rectangular with the apical margin slightly emarginate or triangular). Chilosphex also resembles the subgenus Calosphex Kohl, 1890 ( = niveatus species group of Prionyx) in having the claws with two ventral teeth and in lacking placoids on the male antenna, but differs in lacking pale fasciae on the metasoma, and by the shape of clypeus (the clypeus of Calosphex without distinct emargination and the metasoma with pale fasciae). Chilosphex also resembles the subgenus Harpactopus F. Smith, 1856 ( = crudelis species group of Prionyx) in having the claws with two teeth on the ventral margin, but differs in lacking placoids on the male antenna and in having the female clypeus with a lateral emargination, thus divided into three lobes ( Harpactopus has the male antenna with placoids and the female clypeus without the lateral emargination, not trilobate).