NEW YORK STATE MUSEUM 



weakening many others. The leopard moth, Zeuzera pyrina Fabr., is 

 a very serious borer which has become established about New York city, 

 and has killed hundreds of trees and seriously damaged thousands. The 

 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 almost as injurious to elms. 

 In addition to these there is the San Jose scale, Aspidiotus pernicio- 

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

 ous menace to ornamentals. The gypsy moth, Porthetria d is par 

 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 the most destructive species have come to us from abroad, and this 

 is as true of those infesting 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 have come to us from abroad. 

 The obvious deduction is that every possible precaution should be exercised 

 to prevent the introduction of other species which may become equally 

 injurious. 



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

 tracheate animal,V.with the principal body divisions, namely, head, thorax 

 and abdomen, separate. They may be distinguished 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 normally eight legged when adult, and may be recognized 

 b)- the unsegmented abdomen being fused with the thorax. The large 

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

 with their elongate form, should prevent their being confused with insects 

 proper. 



