APPLE INSECTS — BUDS AND FOLIAGE 



93 



pale hind wings as well as the front ones are mottled with brown 

 dots. Descriptions and figures of the caterpillars indicate 

 that they are much like the lime-tree span-worms ; the dorsal 

 region is described as reddish-brown instead of yellow between 

 the black stripes and the spiracles are in the (;enter of blotches 

 of reddish-brown. 



A Tachina fly parasite is killing some of the caterpillars in 

 British Columbia. This imported pest will doubtless succumb 

 to the same remedial treatment as the native species. 



Bruce's Measuring-worm 



Rachela bruceata Hulst 



This insect was first described from western New York in 

 1886, where a few years later it was quite injurious in apple 

 orchards and on maple trees. 

 Millions of the caterpillars ap- 

 peared in Alberta, Canada, in 

 1902, and the following year 

 hundreds of acres of American 

 aspen or poplar trees were de- 

 nuded in June. The moths have 

 been found in British Columbia 

 also. 



The wingless female moths are 

 about one third of an inch long, 

 light brownish-gray, and closely 

 resemble the females of the fall 

 canker-worm, differing in being 

 only about two thirds as large 



and in having slightly longer stubs of wings (Fig. 100). The 

 winged male moths have a wing expanse of about 1| inches 

 and are of a general very pale brownish color, the wing veins 



Fig. 100. — Bruce's measuring-worm, 

 female moth (X 4). 



