180 Insects injurious to Oaks and Elms. 



707. Some writers have assigned the rank of a separate order to 

 certain groups that present intermediate or anomalous characters, 

 but for the present purpose the above may be sufficient, and in 

 speaking of these orders, we will use the numbers above given, 

 instead of their names. 



708. Insects that attack the Oaks. Of these 223 are enumerated, 

 of which about 38 belong to the 1st class, 9 to the 3d, 103 to 

 the 5th, and 64 to the 6th. To the 1st class belong several de- 

 structive flat-headed and bark borers, the oak-pruner, a leaf-roller, 

 and several species of borers that live in stumps and decaying 

 timber. 



709. The 3d class includes the seventeen -year locust (Clcida sep- 

 temdeceni) , which spends the interval between its appearance as a 

 perfect insect, in the ground, attached to the roots of trees or other 

 plants, and when it comes out to breed does considerable damage to 

 the twigs or trees by stinging them, for the purpose of depositing its 

 eggs. 



710. The 5th class includes the carpenter-moths, whose larvae 

 bore large holes in the wood, acorn- worms, the leaf miners, tent- 

 caterpillars, oak-worms, tussock caterpillar, American silk-worm 

 (from which silk of good quality may be made), geometer moths, 

 and leaf-rollers. 



711. The 6th class includes the gall-flies, that sting the twigs and 

 leaves, of which there are many species. Of these something can 

 be done to destroy the flat-headed borers, by applying soap to the 

 trunk, and by cutting in and extracting them. Where branches 

 fall, from the work of oak-pruners, they may be gathered and burned, 

 to destroy the eggs or insects that are in them. 



712. Insects injurious to the Elms. Of these about 47 are known, 

 of which 14 belong to the 1st class, 1 to the 2d, 4 to the 3d, 25 to 

 the 5th, and 3 to the 6th. The 1st class includes the elm-tree borer 

 (Saperda trldentata), bark-borers, and great elm-beetle. The 3d in- 

 cludes the gall-louse ; the 5th, the canker-worms, span-worms, fall 

 web- worms, and American silk-worm, of the same species found 

 upon the oak ( Telea potyphemus) ; and the 6th the saw-flies. 



713. As a remedy against the canker-worm, printer's ink spread 

 on tarred paper, or the use of troughs filled with oil, or cotton fast- 

 ened around the tree, will prevent the females from ascending it. 



