8 NEW VOUK STATE ML'SEl'M 



weakcnini,^ many Others. Tlic Icoijard moth, Zeuzcra p y r i n a Fabr., is 

 a ven serious borer which has become established about New \'ork cit\'. 

 and has killed hundreds of trees and seriously damaged ihousamls. I he 

 cottony maple scale, Pulvinaria i n n u me rab i 1 i s Rathv., is another 

 very destructive pest affecting soft maples in particular, and the elm 

 bark louse, Gossyparia spuria Mod., is ahnost as injurious to elms. 

 In addition to these there is the San Jose scale, A s p i d i o t u s p e r n i c i o- 

 sus Comst., a pest which thrives on a great number of trees and is a seri- 

 o:is menace to ornanicnlals. The gyps\' moth, I'orthetria tl i s p a r 

 Linn., has become well established in Massachusetts and in the course 

 of time will probably become a pest of prime importance in New York 

 -State. 



It is interesting in this connection to call attention to the fact that some 

 of th(t most destructive species have come to us from abroad, and this 

 is as true of those; inf(;sling shade trees as of the pests feeding on our fruit 

 trees and other cultivated crops. It is only necessary to recall that the elm 

 leaf beetle, leopard moth, the elm bark louse, the mottled willow borer, 

 .San Jose scale and others of that character ha\e come to us from abroad. 

 The obvious ckrduction is that every possible precaution should be e.\crcised 

 to prevent the introduction of other species which may become equally 

 injur'ous. 



Definitions and classification. An insect may be defined as a si.\ legged, 

 tracheale animal, with the ])rincipal body divisions, namely, head, thorax 

 ami abdomen, sijparatt;. riu\' ma)' l)e distinguishetl from the closely 

 related spiders, by the latter having eight legs in the adult condition and 

 the head and thorax being fused into a compound cephalothorax. The 

 mites are normall)- eight leggc-d when adult, and ma\- be recognized 

 by the unsegmented abdomen being fused with the thorax. The large 

 number of legs possessed by the centipede and the millipede, together 

 with their elongate form, should prevent their bt;ing confused with insect.s^ 

 proper. 



