11 



common and injurious in Kentucky. The pine bark- 

 beetles and the fruit bark-beetles now becoming injuri- 

 ous in this State maj^ also be placed here. The greater 

 number of species which attack the trunk are the grubs 

 of beetles. A few are caterpillars (larvae) of moths. 

 The branches and twigs are injured by a host of small 

 species, some of which girdle them, others mine them, 

 still other species do seriou« mischief by placing their 

 eggs in them, while some of the true bugs simply punc- 

 ture and abstract their sap. 



Doubtless the number of insects which feed on the 

 roots of shade trees is large, but the unavoidable difficul- 

 ties in the way of studying their habits has prevented a 

 very full knowledge of this group. Among the better 

 known is the 17-year cicada {Cicada scptendecim) which 

 in its immature condition lives in the earth where it 

 doubtless punctures the roots of oaks and other trees. A 

 few root-feeding beetles are also known to attack trees, 

 but our knowledge concerning their habits is much too 

 scanty. 



The insects belong in great part to the following or- 

 ders, which I have arranged according to their impor- 

 tance as enemies of trees. The moths are placed first with 

 some question, since the beetles are often locally the 

 more destructive, and are especially injurious to cone- 

 bearing trees, upon which the moths do relatively little 

 mischief. 



Moths and Butterflies {Order hepidopterai). This group 

 includes all the caterpillars, such as the caaker-worms, 

 walnut-worms, and the like, with well developed heads 

 and legs Their bodies are often hairy. They live ex- 

 posed on the leaves, or construct webs, while some of the 

 small species mine the leaves or twigs. A few bore the 

 trunks. The adult moths are not in any way injurious. 



Beetles (Order Coleoptera). The insects of this order 



