462 Repoet of the Horticultubist of the 



latter part of April. The eggs are laid near the tips of the now 

 growth. They hatch within a few days. The little white maggots 

 which emerge from them bnrrow into the pith of the shoot. Ac- 

 cording to Slingerland*^^ they burrow downward in the pith until 

 they have reached about half the length of the canes when they 

 work nearly out to the bark and each makes a tunnel around the 

 shoot, thus girdling it from the inside. They continue feeding on 

 the pith at the point where the girdling was done, almost severing 

 the shoots. After doing this injury the maggots proceed to mur- 

 row downward in the pith, finally reaching the base of the shoots 

 where they transform to the pupa stage. This point in their 

 developm.ent is probably reached some time in June. They re- 

 main in this condition until the following April. 



Treatment. — As the insects work inside the shoots they cannot 

 be reached with a spray. Undoubtedly the most practical method 

 of treatment consists in cutting off the wilted shoots several inches 

 below the wilted portion. 



SAW FLY. 



(Monophadnoides rubi Harr.) 



Description. — The adult insects are about the size of a house- 

 fly. They appear in the spring and are most abimdant in May. 

 The eggs are laid from the under side of the leaf within the leaf 

 tissue. They are usually placed along the midrib and larger veins. 

 The tissue above the eggs turns a light brown in color, causing 

 the infested leaves to become spotted. The eggs hatch in about a 

 week. The young larvae are light green in color and are well cov- 

 ered with spine-bearing tubercles. They feed at first on the softer 

 tissues, but finally the entire leaf with the exception of the mid- 

 rib and larger veins is devoured. They also have been known to 

 feed on the tender bark of the new growth and to do some injury 

 to the flowers and fruit. Toward the latter part of June they go 

 into the ground near the bushes upon which they have been feed- 



63 Cornell Univ. Agr. Exp. Sta. Bui. 126, p. 58. 



