PSOROPHORA DISCRUCIANS 571 



late brownisli-blaok scales in a broad longitudinal stripe, a broad band of very 

 broad silvery scales along sides of disk, ante-scutellar bare space surrounded by 

 broad yellowish-silvery scales, prolonged forward in an indistinct median line ; 

 bristles rather numerous, short, black. Scutellum trilobate, each lobe with a 

 patch of yellowish-silvery scales and a group of black bristles. Postnotum 

 elliptical, prominent, blackish brown, nude, shining. Pleura? blackish, clothed 

 with elliptical, flat white scales; coxje paler, with patches of white scales and 

 rows of black bristles. 



Alxlomen subcylindrical, flattened, the distal segments strongly tapering ; 

 dorsal vestiture of black scales with a dark violet-blue reflection, with lateral 

 spots of yellowish-white scales on posterior angles of segments, small and 

 quadrate in dorsal view, large and triangular in ventral view ; venter with broad, 

 apical yellowish-white segmental bands, the basal halves of the segments blue 

 black, the last segment entirely black, with pale scales at margins; first seg- 

 ment dorsally clothed with yellowish-white broad scales and with many rather 

 fine pale setae ; seta? rather short, black, more numerous at ends of segments. 



Wings moderate, membrane faintly infuscated; petiole of second marginal 

 cell about half as long as its cell, that of second posterior cell shorter than its 

 cell ; basal cross- vein nearly its own length distant from anterior cross-vein ; 

 veins brown ; scales black with a blue reflection, especially on costa, outstanding 

 ones broadly linear or ligulate, denser on outer part of wing. Halteres soiled 

 whitish, with dark tips bearing some white scales. 



Legs rather long, moderately stout, ends of tibiae and basal tarsal joints, more 

 especially of hind legs, appearing thickened by long roughened scales ; femora 

 pale at base and beneath with small pale-yellow scales, tips broadly ringed ^nth 

 blue black, middle pair blue-black scaled to base ; knees white scaled ; tibife and 

 tarsi clothed with blue-black scales, except the penultimate joint of hind tarsi 

 which is white scaled. Claw formula, 1.1-1.1-1.1. 



Length : Body about 4 mm. ; wing 3.5 mm. 



Larva, Stage IV (plate 115, fig. 391). Head rounded, wider than long, nar- 

 rowed before eyes, a slight notch at insertion of antennae, front margin broadly 

 arcuate. Antennse very long, as long as head, slender, a little swollen toward 

 base, spined all over; a large tuft of long branched hairs a little before the 

 middle; three long spines and two small digits at tip. Eyes large, transverse, 

 pointed. Both pairs of dorsal head-tufts double, ante-antennal tuft multiple. 

 Mental plate triangular, with a large central tooth and tw^elve on each side, 

 rather small, alike, closely set. Mandible quadrangular, incised without at 

 middle, smooth ; two long filaments before tip ; an outer row of stout cilia ; outer 

 edge roughened but hairless; dentition of four teeth on a process, first and 

 fourth longer ; a filament without, a large and two small teeth at base, a serrate 

 filament within ; process below simple, with patches of hair ; a short process below 

 it ; four long hairs at base within ; four stout hairs at base. Maxilla elongate 

 hemispherical, divided by a narrow suture; inner half spined; a row of long 

 cilia on suture at tip ; outer half with some hairs at base, smooth toward palpus ; 

 a filament at suture on each side. Palpus small, nearly square, with four very 

 small digits. Thorax rounded, wider than long, robust ; hairs abundant but not 

 long. Abdomen stout, anterior segment shorter ; lateral hairs multiple on first 

 segment, double on second, single on third to sixth. Tracheal tubes broad, band- 

 shaped, irregularly flexnous posteriorly. Air-tube large, strongly inflated, 

 tapered on outer half, three times as long as wide ; pecten of five teeth scattered 

 over basal half of tube; single tooth with broad base, a long spine at one end, 

 three subbasal ones, the middle one longest. Lateral comb of eighth segment of 

 five or six scales in a row, upper and lower scales small; single scale with a 



