MONTANA EXPERIMENT STATION. 



175 



THE PEAR AND CHERRY SLUG. 



The larvae or slui^s of this insect feed on the upper surface of the 

 leaves leaving a network (jf veins and the lower cell layers. The 

 leaves so affected turn brown, die and drop off. Whole trees or 

 whole orchards may be thus defoliated. A second growth may be 

 put out thereby weakening the tree so that no fruit is produced the 

 next season. In the early spring the adults may be seen about the 

 treeswhere they gather for the purpose of laying their eggs. The 

 larvae soon hatch and feed on the leaves. They are at first white, 

 but they soon ha\'e a shiny olive colored lluid on their bodies. 



The insects feed on pear, cherry, and plum and about thirty other 

 plants. It shows a preference for pear. 



The species occurs throughout Europe and America and in many 

 of the British colonies. 



Fig. 22. Pear and Cherry Slug: a, adult saw-fly, female; b, larva with slime 

 removed; c, same in normal state; d, leaves with larvae, natural size; a, b, 

 c. much enlarged. (Marlatt, Circular 26, Sec. Series, Div. of Entomology, U. 

 S. Dept. of Agr.) 



