MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 323 



the corresponding- form of the fly is known as a maggot. The 

 plum ctirculio (figs. 25-27), the apple tree borer (figs, i, 2), 

 the blundering June beetle, and the potato beetle are members 

 of the Coleoptera, insects having hard, shell-like fore wings 

 which meet in a longitudinal line along the middle of the back. 

 Both the larvae (known as grubs) and the adults have biting 

 mouth parts and in some species are equally concerned in the 

 destruction of plants. Some lady beetles on the other hand 

 are beneficial because they feed on small injurious insects such 

 as scales and aphids. Ants, bees, wasps, a host of species of 

 m.inute 4-winged parasitic flies, as well as some injurious saw- 

 flies are members of the order Hymenoptera, the adults of 

 which are four-winged. The larvae, most of which are known 

 as grubs or maggots, usually have well developed heads with 

 biting mouth parts and frequently provided with legs. 



While the foregoing classification is adopted in most text 

 books, it is more convenient in dealing with the species of the 

 apple to arrange them in accordance with the character of the 

 injury they cause and to this end we will first divide them into 

 3 primary groups. 



A. Injuring root, trunk or branch; borers and sap feeders. 

 Page 323. 



AA. Injuring the foliage; biting or • sucking insects. 



Page 333. 



AAA. Injuring the fruit; maggots, caterpillars, bugs and 



beetles. Page 366. 



A. INJURING ROOT, TRUNK, OR BRANCH. 



a. Borers in the wood. 



1. A large white grub about i inch long when grown, with 



brown head ; thorax not much thicker than the abdomen. 

 Bores mainly at the base of the trunk. Its presence is 

 indicated by the wood dust it throws out of its burrow, 

 (fig. i). Round-headed borers. Page 324. 



2. A whitish grub about Yi inch long when grown, with flat- 



tened thorax about twice as wide as the abdomen. Works 

 on the trunk and large branches, (fig. 2.) 



Flat-headed borers. Page 326. 



3. A verj- small larva which lives in small rounded "shot holes" 



about I -16 inch in diameter. Adults are small brown 

 beetles. Shot-borer beetle. Page 328. 



