170 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. 



four and the inner angle of six; segments three to live faintly 

 unimlated. 



]*r()thorax transverse, only about three-fourths as long as head, but 

 nearly twice as wide as long, rounded at the angles; sides slightly con- 

 caved, bearing a few small spines, of which only the bright bases are 

 usually visible; reticulation heavy, but interrupted across the middle. 

 Mesothorax one and one-fourth times as wide as the prothorax; 

 reticulation upon mesonotum quite heavy, regular upon anterior half, 

 ui)on posterior half elongated toward a deep incision in the hind 

 margin of the plate, the longitudinal thickening becoming weaker. 

 Mctanotum prominent, triangular, strongly reticulated. Wings very 

 slender, not nearly reaching to tip of abdomen, broadened abruptly at 

 base to more than twice their diameter at middle: only one distinct 

 longitudinal vein, and this sends off a short oblique l)ranch to costal 

 vein. Anterior fringe very short and sparse; posterior cpiite long and 

 heavy; no prominent spines upon veins. Legs rather short and thick; 

 pale yellowish, except coxse brownish; first and second pairs about 

 equally long; hind pair a little longer; all legs reticulated. 



Aljdomen elongate-ovate, pointed at tip; dorsum reticulated; seg- 

 ments two to eight with irregular transverse brown line near front 

 edge of each. Spines upon abdomen mostly small and indistinct; most 

 prominent ones situated upon middle of dorsum of segments two to 

 eight, close to median line; these gradually increase in size posteriorly; 

 anal spines short and w^eak. Color of abdomen varies from brownish 

 y(>llow to dark brown; last two segments usually much lighter but less 

 variable in color than rest of abdomen, being regularly brownish yel- 

 low tipped with dark brown. 



Redescriljed from eight females. 



Male unknown. 



In Germany this species is called "Black Fly." 



Food plants. — Aspidiuni, azaleas, Croton, dahlias, ferns, Liliace^e, 

 Pellea hastata, Phhxc, pinks, verbenas, vines, etc. 



Hahitat. — England (Walker, Cameron), German}^ (Bouche, Bur- 

 meister, Bremi, Jordan, Bohls), Vienna (Heeger, Low), Finland (Reu- 

 ter). United States: District of Columbia, Iowa, Massachusetts, 

 Michigan. 



Life history unknown. 



In liis original description Bouche states that he believes the native 

 land of this species is America. In both countries, however, it has 

 been found almost entirely confined to greenhouses and feeding upon 

 greenhouse plants. 



It has been very injurious in some places. Packard calls it "one of 

 our greatest pests in hothouses," and Cook records it as "one of the 

 worst pests around Detroit, at Adrian, and in the southern counties" 

 of Michigan. 



