13 



TWT(!-WKKVTI,S. 



Tliis is a class of snout boelles or .so-called weevils which deposit 

 tlicir eoj^s in the li\iMj^, dying, and dead twigs of trees, and the larva? 

 mine in the i>ark and ])ith. When they infest the twigs of living trees 

 they often do considerable damage. 



TWKi CATEUPIIXARS. 



These are the larva* of moths, which burrow into the terminal twigs 

 of pine and other conifers and often cause serious harm. There are 

 also certain kinds which attack the bark of the twigs and cause masses 

 of pitch to form, in which they live. 



scalp: inskcts. 



This is an extensive class of insects which infest the bark of all sorts 

 of trees and are often very injurious. The 3^oung, after hatching 

 from tiie cg^^ or mother scales, crawl about and attach themselves to 

 the bark by means of their long, slender beaks. Many species exude 

 a kind of wax which forms a scale-like covering which protects them 

 during their period of growtli. 



PLANT-LICE. 



These are similar to the plant-lice which infest the leaves, but cer- 

 tain kinds confine their attack to the twigs, especially some t)f those 

 tx'longing to tlu> genus Dfe/uti/.s. Some of them are covered with a 

 cottony or wool-like substiince, while others are large, Idack. and 

 shining. 



OALL INSECTS. 



There aiv, many kinds of gall insects which produce galls on the 

 twigs of forest trees, and like those causing gjiUs on the leaves 

 represent several orders and families. 



CICADAS. 



This is a class of insects of which the periodical cicada is a cT)mmon 

 example. They often cause serious injury to the twigs, which they 

 })uncturc for the purpose of depositing their eggs. 



INSECTS INJURIOUS TO FRUIT OR SEEDS. 



'i'his designation refers to insects which attack the young to niatur(>d 

 fruit and seeds on the living tree, or aftei- the}' have fallen. 



WKKVILS. 



This is a class of snout-beetles which arc often very injurious to 

 acorns and \arious kinds of nuts. 'I'he eggs are dcjjosited in the young 

 fruit and the young larva' li\'e on the iiuier portion until the mit or 

 fruit has maturiMJ and fall> tot he ground, when t hey burrow their way 

 out and go into the ground to transform to adults, which come out 

 the next year in time to repeat tlie operation. 



