INSECT ENEMIES. 97 
longer able to perform their office. Secure an early 
growth of wood, that will ripen in time to be ready for 
all changes of weather, and you will have the satisfaction 
of haying done wisely. 
CHAPTER XIX. 
INSECT ENEMIES OF THE QUINCE. 
EntTomoLoaists have estimated that, on an average, 
there are from four to six insect enemies to each variety 
of plants. The insect enemies of the quince exceed this 
average, but are not so numerous as the enemies of the 
apple. Quite a portion of them are alike the enemies of 
both. 
ATTACKING THE TRUNK AND BRANCHES. 
1. THE RoUND-HEADED APPLE-TREE BORER (Saperda 
candida, Fabr.; Saperda bivittata, Say).—This is an 
American insect, first described by Thomas Say in 1824. 
Trees growing on high ground are, other things being 
equal, more largely infested than those on low land. In 
its larval state it is called the Round-headed Apple-tree 
Borer, to distinguish it from a flat-headed species, which 
also preys on the apple, but not on the quince tree. In 
its imago, or perfect state, it is commonly known as the 
Two-striped Saperda. The full-grown larva is about an 
inch long, cylindrical in form, fleshy, and tapering from 
the head to the tail. The round head is of a chestnut- 
brown color, horny, and polished. The jaws are quite 
black, and fitted to cut the fiber of wood much as it is 
cut in boring with an auger. The chrysalis is lighter 
colored than the larva, and is marked by transverse rows 
of minute spines on the back, with a few at its extremity, 
which probably aid it in casting off its puna skin. The 
