THE CANADIAN ENTOMOLOGIST, 69 



NOTES ON PEGOMYIA BICOLOR (Wiedemann), A LEAF- 

 MINING FLY NEW TO CANADA. 



BY REV. THOMAS W. FYLES, SOUTH QUEBEC. 



Egg laid on the under side of the leaf of the Dock (Rumex obtusi- 



fol'nis). Newly hatched larva bites through to the upper surface of the 



parenchyma, and works under the epidermis, until the leaf presents a 



blistered appearance. Sometimes three or four larvas are found in one 



leaf. 



Full-grown larva, four-tenths of an inch long, white, semi-transparent. 

 Segments marked with greenish yellow. Head retractile, furnished with 

 a snout-like process, the apparent use of which is to raise the epidermis 

 as the creature feeds. Mouth set back. Alimentary canal visible under 

 the microscope, also two ducts terminating in spout-like organs protruding 

 from what appears to be the upper edge of the somewhat truncated last 

 segment of the larva. The tuberculose spiracles on the second segment 

 very conspicuous ; on the third, less so, and so on diminishing. 



The insect left the leaf and pupated on the 22nd of September. 

 Whilst undergoing the change it assumed a leaden-blue color. 



Pupa, two and a half tenths of an inch in length ; chestnut-brown ; 

 ovate. Segments slightly marked. Two considerable prominences at the 

 head. The anal protuberances, as above described, hardened and con- 

 spicuous. 



Perfect insect appeared in a warm room early in April. It presents a 

 bristly appearance. Head, large. Front, white. Palpi, red. Eyes, 

 full, madder brown in color. Large joint of antennas sienna-colored, 

 infuscated. Thorax, large and rounded, rich dark brown. Legs, sienna- 

 colored. Wings medium sized. Costal margin thickly set with short 

 hairs. Veins broadly marked, dark brown. Wing-sockets furnished 

 beneath with a white fibrous edging. Halteres small and light-colored. 

 Abdomen small compared with head and thorax, and long as compared 

 with its own diameter, cylindrical, truncated, sienna-colored, set with long 

 brown bristles. 



I am indebted for the identification of this insect to Mr. Meade, who 

 says : " I belive that this species has not been recorded as an inhabitant 

 of North America, but it is very common in the north of Europe. I have 

 bred numerous specimens from the leaves of both Rumex obtusifolius 

 and R. crispus. Zetterstedt says it is equally common in the north of 



