26 
THE CARROT RUST FLY. 
(Psila rosse Fab.) 
This imported pest, which has been noted as injurious to carrots in 
Canada since 1885, made its appearance during 1 the season of 1901 in 
New York, and did considerable injury. 
November 14 and 19, 1901, Mr. James Granger, Broadalbin, N. Y., 
sent specimens of the maggot which proved, on rearing, to be this 
species, and which he found at work in a celery field during the sum- 
mer. The larva? seemed to begin eating into the thick part of the root 
when the plant was about half grown, stunting it so as to make it 
worthless for market. About 6,000 plants had been ruined during the 
season, and traces of the ravages of the maggot were found all over a 
field containing 60,000 plants. 
It is to be regretted that the rearing and subsequent identification 
of the species was made so late in the season that it was impossible to 
make any biological observations. The importance of the species as a 
pest in Europe and its prospective increase and injuriousness in this 
country are such, however, that it is deemed advisable to present at 
this time what is known concerning the insect and its life history. All 
that has been hitherto published on its occurrence in America is from 
the pen of Dr. James Fletcher, Dominion entomologist of Canada. 
Attack on carrots is not difficult of recognition. The leaves of the 
young plants early in the spring turn reddish, and the roots are found 
to be blotched with rusty patches, particularly toward their tips. The 
roots when stored for winter, although not always manifesting an} r 
degree of injury on the outer surface, may at times be perforated in 
all directions by dirty brownish burrows, from which the whitish or 
yellowish larvae may be found sometimes projecting. 
DESCRIPTIVE. 
This species is quite minute, the adult or parent fly measuring only 
about one- sixth of an inch (l mm ) in length, with a wing expanse of 
a little more than three-tenths of an inch (8 mm ). The color of the 
body is dark green, described by some authors as black, and it is 
rather sparsely clothed with yellow hairs. The head and legs are pale 
yellow, and the eyes are black. The general appearance of the two 
sexes is shown at $ and ? , respectively (fig. 6). It will be noted that 
the male abdomen is rounded at the apex, while that of the female is 
prolonged into a rather acute point. A more detailed description 
is given by Curtis. 
The larva, about half grown, is figured at/', g. It is paler than the 
more mature larva. The full-grown larva resembles rather closely 
that of the cheese maggot, to which this species is nearly related, but 
is much darker in color, being rather dark brown, with the segments 
