THE TRIBE CHALCIDINI — BURKS 313 



SPILOCHALCIS ARCANA (Cresson) 



FiGUBE 9, e 



Smicra arcana Ckesson, Trans. Amer. Ent. Soc, vol. 4, pp. 36, 44, 1872. — Howaed, 

 U. S. Dept. Agr. Bur. Ent. Bull. 5, p. 33, 1885.— Gees son, Synopsis of the 

 families and genera of the Hymenoptera of America north of Mexico, p. 

 233, 1887. — Balla Tobre, Catalogus hymenopterorum, vol. 5, p. 373, 1898. — 

 ScHMiEDEKNECHT, Genera insectorum, fase. 97, p. 34, 1909. — Ceesson, The 

 Cresson types of Hymenoptera, p. 74, 1916. 



Smicra encausta Ceesson, Trans. Amer. Ent. Soc, vol. 4, pp. 37, 46, 1872. — 

 Howard, U. S. Dept. Agr. Bur. Ent. Bull. 5, p. 34, 1885. — Cresson, Synopsis 

 of the families and genera of the Hymenoptera of America north of Mexico, 

 p. 233, 1887. — Daixa Torre, Catalogus hymenopterorum, vol. 5, p. 376, 1898. — 

 ScHMiEDEicNECHT, Genera insectorum, fasc. 97, p. 35, 1909. — Ceesson, The 

 Cresson types of Hymenoptera, p. 74, 1916. 



This usually red or orange species is most easily recognized by its 

 compact form, short antennal scape and stout flagellum, very broad 

 anterolateral carina of the pronotum, prominent anterior lamina on 

 the interantennal projection, and the semiglobose metafemora with 

 18 or more small, closely set teeth, the basal one of which is acute. 



Description. — Red, orange, or yellow with broad black marks; 

 vertex and occiput, mesopraescutum except two wedge-shaped lateral 

 marks, lobes of mesoscutum except anterolateral angles, axillae, nar- 

 row longitudinal mesal and short apical marks on mesoscutellum, 

 metacoxae except small dorsal stripe, central and small apical spots 

 on outer side of metafemur, entire propodeum, petiole, and gaster, 

 except bases of third and fourth segments, black. 



Female : 4-6 mm. Apex of antennal scape not quite reaching level 

 of ventral margin of anterior ocellus, pedicel four-fifths and ring seg- 

 ment two-fifths length of segment 4, 5 slightly shorter than 4, 5 to 11 

 almost equal in length", 12 and 13 combined only slightly longer than 

 11 ; scrobe cavity deep, edge carinate at ventral margin ; interantennal 

 projection provided with a strong anterior lamina ; f rons deeply and 

 closely punctured, punctures tending to coalesce so as to form irreg- 

 ular transverse and oblique carinae, frontal tentorial pits located just 

 laterodorsad of anteimal bases; width of malar space slightly less 

 than one-half height of compound eye ; f rontogenal suture extending, 

 for one-fourth its length, ventrad from compound eye, then curved 

 abruptly toward mandible, genal area caudad of suture with three 

 or four irregular transverse carinae; combined widths of compound 

 eyes two-thirds interocular width at level of antennal bases; left 

 mandible with two rather blunt teeth, right mandible with three 

 acute teeth, ventral one largest ; diameter of posterior ocellus slightly 

 less than one-half interocellar width. 



