168 BULLETIN 66, UNITED STATES NATIONAL MUSEUM. 



34. Genus MECYNOCERA Pierce (1908). 



Type of genus. — Mecynocera Jcoebelei Pierce. 



Name derived from /iij/cww ( = elongate) + atpac ( = horn), referring 

 to the elongate antennae, which are characteristic of the Elenchidae. 

 This genus is confined to North America. The hosts belong to 

 the genus Liburnia, Homoptera, Fulgoridae. 



It differs from Elenchus principally by having the ninth dorsal 

 segment of the abdomen obliquely truncate from the dorsal median 

 base to the ventral apex, and terminated by the reflexed oedeogus, 

 which is shallowly siphonated or sinuate. The maxillae are feebly 

 two-jointed, the first joint bearing about its middle a filiform process 

 with a knobbed apex, reaching the tip of the second joint of the 

 maxillae. 



i. MECYNOCERA KCEBELEI Pierce (1908). 



Elenchus tenuicornis Perkins, 1905, not Kirby, 1815. 



Host. — Liburnia campestris, Liburnia lutulenta; Columbus, Ohio, 

 female, August 17; males, August 11; collected by Mr. A. Koebele 

 while endeavoring to find parasites of fulgorids for introduction 

 into Hawaii, and named in his honor (fig. 3, nos. 15, 16; pi. 15, 

 figs. 2, 3, 4, 5). 



Male. — Length, 1 mm.; wing expanse, 2 mm. Slender, frail, yel- 

 lowish. This insect is a typical elenchid, although typifying a new 

 genus closely related to Elenchus. The antennae are five-jointed, 

 taeniaeform; the first two joints more or less cylindrical; third, lat- 

 erally produced into a long ribbon-like appendage with strongly sen- 

 sitized surfaces; the fourth leaving the third at a distance from its 

 base less than the length of the third; fifth joint flattened as the two 

 preceding, separated from the fourth in the same plane by a trans- 

 verse constriction and extending beyond the tip of the third by one- 

 half its length. The surface of the antennae is typical. The tuber- 

 cles, however, are not as closely guarded as in Acroschismus. Anten- 

 nae very nearly as long as thorax. Eyes with comparatively few hairs 

 and with the lenses close. Maxillae feebly bilobed with a chitinous 

 filament from the middle of the first segment. Mandibles short, stout, 

 acute. Prothorax a mere band, and mesothorax double. Elytra, 

 clavate, with a long peduncle; club paddle-shaped, with sensitive 

 surface. Wings delicate hyaline. The veining consists of five pri- 

 mary veins, the first and second costal and subcostal, the third 

 radial, and the fourth medial; fifth anal with a short unattached 

 vein between the radius and medius. Tarsal joints two, the second 

 arising considerably before the apex of the first. Trochanters of the 

 first two pairs of legs very long, as long or longer than the femora. 

 Femora of posterior leg nearly three times as long as trochanters and 

 about twice as long as coxae; coxae depressed for reception of trochan- 



