Ciy Cniutbian Entomologist. 



VOL. XVII. LONDON, ONT., JANUARY, 1885. No. i 



ENTOMOLOGY FOR BEGINNERS. 



THE RASPBERRY SAW-FLY. 

 Selandria rubi Harris. 



BY THE EDITOR. 



This destructive insect appeared in great force during the past season 

 in many parts of our Province, doing much damage to the foliage of rasp- 

 berry plants. Although in form and habits the larva of this insect much 

 resembles the currant Avorm, it is not nearly so well known, nor is it usually 

 so promptly recognized. There are several reasons for this. The rasp- 

 berry saw-fly does not appear in such flocks as the currant worm, because 

 the eggs are laid singly and not often near together ; nor is the larva 

 easily detected owing to the fact that in color it so exactly resembles that 

 of the leaf on which it feeds. 



The eggs are oval, yellowish white and semi-transparent, and are buried 

 beneath the skin of the raspberry leaf near the ribs and veins, placed 

 there by means, of the saw-like apparatus situated at the extremity of the 

 body of the female, by which slits are cut in the tissues of the leaf The 

 skin covering the egg is so transparent that the movements of the enclosed 

 larva may be observed several days before it is hatched. It escapes 

 through an irregular hole made on one side of the egg. 



The newly-hatched larva is about one-twelfth of an inch long, with a 

 greenish-white head having a black eye-like spot on each side. The body 

 is nearly white, semi-transparent and thickly covered with transverse rows 

 of white spines. As it grows older the color changes to green, and when 

 full grown it measures about three-quarters of an inch in length and 

 appears as shown on the leaf in figure i. The body then is of a dark 

 green color, and is thickly set with pale green branching spines. In 

 figure I some of the segments of the body are represented, magnified, 

 showing the arrangement of the spines on the back and side. The head 

 is small, of a jjale yellowish green color, with a dark brown dot on each 



