336 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Genus Pholidotus Hermann 



Figubes 268, 616, 618, 1225, 1234, 1305, 2148, 2154, 2155 



Pholidotus Hermann, Nova Acta Acad. Caes. Leop.-Carol., vol. 

 96, p. 229, 1912. Type of genus: Pholidotus rubriventris 

 Hermann, 1912, by original designation. 



Rather large, quite robust flies with the abdomen 

 broad, as wide as the thorax, short and rather flattened. 

 The pile is flat appressed and short, especially on the 

 abdomen and they are distinguished from other groups 

 with the long, knifelike, greatly compressed proboscis, 

 by the dense bright scales on the face, which are not con- 

 fined to the eye margins. The anterior branch of the 

 third vein is nearly or quite straight; the mesonotal 

 callosity has no pile or bristles ; the first posterior cell 

 is open and hind femur stout but not swollen. Length 

 16 to 20 mm. 



Head, lateral aspect : Face moderately produced, more 

 prominent on the lower half where it is slightly gibbous 

 but retreating below and gently swollen in the middle. 

 The eye is short, slightly narrowed ventrally from the 

 posterior aspect, plane through the middle third, 

 strongly convex and recessive below. The pile is 

 abundant but delicate and rather long on the ventral 

 half, shorter and scanty in the middle and dorsally 

 where it is a little longer. Bristles begin in the middle, 

 are distinct but rather weak, black, short and slightly 

 curved ; there are 10 pairs and they end before the medial 

 comer of the eye. The occiput is quite short, barely 

 visible in the middle, slightly more prominent below; 

 from the dorsal aspect the vertex is strongly excavated 

 posterolaterally. Proboscis exceptionally long, directed 

 forward and unusually thin or laterally compressed and 

 knifelike. From the dorsal aspect it is rather abruptly 

 swollen only at the immediate base, the same is true from 

 the lateral aspect, where it is swollen only ventrally ; the 

 whole outer portion has parallel sides, there is no medial 

 ridge and the apex is quite obtusely rounded and al- 

 most truncate, with a few minute hairs apically and 

 especially below. Base ventrally with a few fine, rather 

 short hairs. Palpus slender, cylindrical, the first seg- 

 ment rather wide, flattened, excavated and fused 

 medially; the second segment and the first bear fine, 

 ventral pile; the second segment has 2 long, slender 

 bristles at the apex. 



Antenna attached at the upper fourth of the head ; it 

 is elongate and slender, longer than the head ; the first 

 segment is robust and a little longer than the second; 

 the second is longer than wide. Third segment about 

 2 or 2% times the combined length of the first two. 

 Along the middle it is barely wider than the second seg- 

 ment and is very slightly narrowed distally ; apex with 

 a small, dorsal, exposed, characteristic spine, and no pit. 

 Head, anterior aspect : The head width is a little less 

 than twice the height. The width of the face below the 

 antenna is less than a third the head width ; face with 

 parallel sides. The subepistomal area is moderately 

 large, concave, slightly oblique and bare. Face with 

 scanty pollen and for the most part shiny ; the lateral 



third on the upper half and the whole lower lateral 

 margin more narrowly is densely covered with broad, 

 silvery scales. Epistomal margin with a pair of long, 

 slender, black bristles curved downward and beneath 

 them a pair of shorter, white bristles and 2 other similar 

 ones along the upper, lateral, epistomal margin. The 

 front is quite short; the middle half is set off by a shal- 

 low, lateral crease or fascia. The steep lateral portion 

 of the front bears a number of fine, delicate hairs next 

 to the eye but no bristles. Vertex rather deeply ex- 

 cavated, with steeply oblique sides. The ocellarium is 

 set rather far behind the anterior margin of the eye, it is 

 large, triangular and moderately high, bearing rather 

 flat ocelli and over the middle 4 or 5 pairs of rather short, 

 slender, bristly, pale hairs. Anterior eye facets very 

 strongly enlarged ; central part of eye quite flat. 



Thorax : The thorax is everywhere pollinose, slightly 

 more convex anteriorly. The pile on the mesonotum is 

 short, fine, scanty, bristly and suberect with a row of 

 equally short, acrostical pile and with dorsocentral pile 

 not differentiated anteriorly and poorly behind the 

 suture where there are 4 or 5 delicate, slightly longer 

 hairs. Humerus with moderately long, bristly pile. 

 The rather short, comparatively weak lateral bristles 

 consist of 1 notopleural with 2 shorter, weaker ele- 

 ments, of which 1 is posthumeral, 3 supraalar, 1 postalar 

 and no scutellar bristles. The scutellum is convex, 

 moderately thick, pollinose, the margin with 3 pairs of 

 slender, bristly hairs, the disc with a few minute hairs, 

 the base with a shallow crease. The propleuron has 

 abundant, fine, long pile; pronotum with bristly pile 

 only. The posterolateral pronotum has long, fine pile 

 only. The dorsal pronotum and the ventral prosternum, 

 the latter dissociated and widely divided by membrane 

 in the middle below, both appear to be unusually con- 

 vexly protuberant. Mesopleuron with abundant, long, 

 fine pile on nearly the whole surface and with a single, 

 distinct, moderately stout bristle on the posterior border 

 at the upper third. The sternopleuron seems to be 

 without pile except anteriorly; pteropleuron apilose; 

 the hypopleura has considerable fine pile posteriorly. 

 Metapleuron strongly convex with a wide band of long, 

 bristly pile ; true bristles absent. Lateral slopes of the 

 metanotum pollinose only ; nearly the whole surface of 

 the lateral metasternum and the comparatively wide 

 chitinized ventral metasternum bear abundant, long, 

 fine pile. Postmetacoxal area distinctly membranous, 

 although the lateral metasternum encroaches to some ex- 

 tent anteriorly; tegula with setae. Prosternum not 

 dissociated. 



Legs: All the legs are stout; the anterior and pos- 

 terior pairs are a little more thickened than the middle 

 femora; the thickening is spread over the middle of the 

 anterior femur and chiefly beyond the middle on the 

 hind femur but nowhere conspicuous. Hind femur 

 with a few, fine, suberect hairs dorsally and dorsolater- 

 ally. Bristles are comparatively few, mostly short and 

 quite weak, occasionally longer but always finely atten- 

 uate apically. On the hind femur the bristles consist 



