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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



PAET 1 



Genus Hadrokolos Martin 



Hadrokolos Martin, Amer. Mus. Nov., no. 1980, p. 3, 1959. 

 Type of genus: Holopogon texanus Bromley, 1934, by origi- 

 nal designation. 



The following description is from Martin : 



The genus Hadrokolos is erected to receive three species of 

 asilids belonging to the subfamily Dasypogoninae tbat are 

 related to the genus Holopogon Loew. In general, the known 

 species of Hadrokolos are more bristly and the hair is more 

 sparse and shorter than is the case with the species of Holopogon. 

 The diameter of the femora is greater than the largest diameter 

 of the tibiae, which is generally not true of Holopogon, in which 

 the tibiae have the greatest diameter. 



In Hadrokolos the oral margin has a clump of bristles medi- 

 ally and a few longer bristles laterally, and also bristles are 

 above the clump ; dorsally the thorax bears at least posteriorly 

 and sometimes anteriorly strong dorsocentral bristles, also the 

 postalar bristles are strong and long; the scuteUum bears two 

 or more strong, long, marginal bristles ; the lateral margins of 

 the abdominal tergites have very sparse, short hair; the anal 

 cell is very narrowly to broadly open in the margin of the wing ; 

 abdominal segments 7 and 8 both rotate approximately 40 

 degrees or more from the longitudinal axis of the body so that 

 the two broad, long, ellipsoidal claspers of the male genitalia 

 hang ventrad, with the posterior margins curving anteriorad. 

 In Holopogon there is a similar turning of segments 7 and 8, 

 but the claspers are greatly reduced in length. 



Distribution : Nearctic : Hadrokolos cazieri Martin 

 (1959); pritchardi Martin (1959); texanus Bromley 

 (1934). 



Genus Pseudoholopogon Strobl 



Figubes 132, 465, 1053, 1062, 1591, 1876 



Pseudoholopogon Strobl, Werner Ent. Zeitung, vol. 17, p. 29S, 

 1898. Type of genus : Dioctria chalcogaster Dufour, 1850, 

 by original designation. 



Small flies characterized by the extremely stout hind 

 tibia and tarsus, the broad wings, and the slender 

 antenna that has two wide, compressed microsegments, 

 together with a third, small, dorsal, spine-bearing 

 microsegment. This last microsegment has a conspic- 

 uous, dorsal, bristly spine. Middle of the face with 

 very long, abundant, bristly pile. This genus is sepa- 

 rated from Holopogon Loew by the f orm of the antenna. 

 The massively thickened hind tibia and tarsus represent 

 only an exaggeration of Holopogon tendencies. Length 

 9 or 10 mm. 



Head, lateral aspect : The head is not developed below 

 the eyes. The head is rather long, most of it incor- 

 porated in the eye which is long; the eye is also very 

 strongly convex anteriorly, gently convex behind, and 

 equally developed above and below. Face short, gently 

 convex, slightly more extensive on the lower half than 

 dorsally. The occiput is thick and well developed, 

 especially medially; it slopes gently down to the eye 

 margins dorsally and ventrally. Pile of the occiput 

 long and fine and abundant ventrally and crinkled; 

 the dorsal portion of the occiput bears numerous, 

 quite slender bristly hairs; 2 or 3 of these elements 

 behind the vertex are stout and most of them pro- 

 clinate. The proboscis is short, subcylindrical, slightly 



swollen towards the base; the apex is truncate in a 

 slightly oblique, dorsoapical direction. The immediate 

 apex of the proboscis and the ventral apical portion 

 on the outer fourth both bear a number of fine, bristly 

 hairs ; basal half of the ventral surface with numerous, 

 long, stiff, divergent hairs. The proboscis is scarcely 

 longer than the face and is directed almost horizontally 

 f orward. Palpus quite small ; clearly of two segments ; 

 both segments short, the first excavated, the second 

 microporate and with only 2 or 3 bristly hairs sub- 

 apically and below. Second segment shorter than the 

 first, attached at an oblique angle and directed upward. 



The antenna is attached at the upper fourth of the 

 head, long and slender, the first two segments approx- 

 imately equal in length. The third segment is laterally 

 compressed, as long as the first two combined and car- 

 ries two laterally compressed microsegments, each 

 nearly as wide as the apex of the third segment and 

 each slightly convex dorsally and ventrally and each 

 approximately as long as wide. Second microsegment 

 with an additional conspicuous, dorsoapical, short, 

 spine-bearing microsegment, making a total of three 

 microsegments. This third microsegment is swollen 

 and cylindroid and the spine is apical. The first seg- 

 ment of the antenna has 6 to 8 unusually long, slender, 

 bristly hairs. Second segment with 2 long, stiff bristles 

 ventrally and 2 shorter, more slender bristles dorsally. 



Head, anterior aspect : The face below antenna about 

 one-fourth the head width and divergent below. The 

 front is as wide as the lower face. Subepistomal area 

 small, concave and nearly or quite horizontal. The 

 face is coarsely pubescent, bearing dense, long, quite 

 slender bristles down the entire length of the middle 

 half of the face, leaving the lateral fourth on each 

 side without bristles, except opposite the epistomal 

 margin, where the bristles extend to the eyes. There 

 are no stout bristles present. The front is rather long, 

 due in part to the posterior position of the ocelli. It is 

 thinly pollinose, with a wide, lateral band of abundant, 

 long, bristly pile which anteriorly extends inward as 

 far as the outer margin of the antenna. The front is 

 moderately divergent and not convergent at the ver- 

 tex. Vertex moderately excavated, the ocellarium large, 

 set opposite the upper posterior corners of the eyes; its 

 sides are vertical and it bears between the ocelli 3 or 4 

 pairs of long, slender, bristly hairs, with 2 or 3 addi- 

 tional hairs behind the ocelli. Anterior eye facets con- 

 siderably enlarged. 



Thorax : The pleuron is very thinly appressed micro- 

 pubescent. Pile of mesonotum is long and quite fine, 

 of bristly character but scanty in quantity, much of 

 the mesonotum is shining and not pubescent. There 

 are a few fine, long, acrostical hairs anteriorly and 

 similar dorsocentral elements poorly differentiated an- 

 teriorly but becoming longer before the scuteUum. 

 Humerus with a few fine, long, backwardly curled 

 hairs. The following complement of quite slender, 

 weak, mostly short, lateral bristles present: notopleu- 

 ron with 1 long, moderately stout bristle and 1 fine, 

 stiff, short hair; postalar with several short, stiff 



