292 MAINE AGRICULTURAL EXPERIMENT STATION. 1914 



validity of the species difficult to differentiate from characters 

 of the adults. 



The paper begins with a general statement of the classification 

 of the group. The main facts in the development of these 

 insects are then discussed, including the method of reproduction 

 the varied feeding habits of the larvae, the differences in ap- 

 pearance of given species due to molts, and the peculiar prepara- 

 tions of the larvae before pupation. 



Descriptions of the larvae of the subfamilies of the group are 

 given, and illustrated by the plate of 27 figures. 



A sawfly belongs to the same order of insects as the bees and 

 wasps but instead of having a sting for an ovipositor, its egg 

 laying apparatus is equipped with a small saw with which it 

 cuts a slit in the tissue of the plant and deposits an egg in the 

 opening. The adult or winged sawfly does practically no harm, 

 but the young which hatch from her eggs are as greedy as 

 caterpillars and as completely demolish the foliage they feed 

 upon. These larvae resemble hairless caterpillars somewhat in 

 their appearance as well as in their feeding habits and are fre- 

 quently mistaken for them. 



The eggs are always laid by the female within the tissue ot 

 the food plant. Where the larvae are borers, they are laid in 

 holes pierced in the stems of bushy plants or in the limbs or 

 trunks of living or recently dead trees. Where the larvae 

 are leaf-feeders, the eggs are placed in slits sawed by the female 

 from the under surface and located between the two layers 

 of parenchyma. A few species insert their eggs in the petiole 

 of the leaf, some of the gall-making species in the leaf-buds, 

 and one in the blossoms of cherry on the sepals or the upper part 

 of the calyx cup. The eggs are oval in outline, flattened, usually 

 white in color, though sometimes bluish or greenish, and very 

 difficult to locate when first laid. They swell after a short time 

 to twice their original size and push out the surface of the leaf 

 so that it appears to be covered with little mounds. 



The manner of feeding is strikingly varied. With many 

 species, the young larvae as soon as they emerge from the 

 egg eat holes through the leaf and continue feeding around 

 the circumference of the hole clinging to the leaf with their 

 thoracic legs and holding the body S-shaped in the hole. Some 

 species are leaf-skeletonizers for the first two or more stages 



