Order HOMOPTERA. 



This ordinal term is employed for those Rhyngota in which the two 

 pairs of wings are either similar in texture, as in the plant-lice or 

 "Cicada," or the primaries are of the same texture throughout, though 

 this may be different from that of the secondaries, as in the leaf-hoppers. 

 The mouth parts are composed of four lancets, of which two are usually 

 grown together concealed in a jointed beak, except in the Coccidse or 

 scale insects, in which the mouth parts are quite generally aborted in the 

 males and reduced to thread-like lancets in the females. Usually the 

 base of the beak is on the under side of the head, and its point is directed 

 backward so that it rests between the haunches of the fore-legs. 



All the species are plant feeders, 

 piercing the tissue by means of the 

 lancets and exhausting the cells be- 

 neath. They are, therefore, of eco- 

 nomic importance, and, as a matter 

 of fact, some of our most destructive 

 species belong to this order. 



In a general way the transforma- 

 tions are incomplete; but the life his- 

 tories of the species are often involved 

 and sometimes curiously unique. No 

 general recommendations for treat- 

 ment can be given, except that only 

 contact poisons are of any avail and 

 stomach poisons are never indicated. 



Since the previous list was pub- 

 lished this order has received much 

 attention from collectors and students, 

 and the number of species here listed 

 has been greatly increased. Most of 

 the species previously included as 

 probable inhabitants have been defi- 

 nitely authenticated and a few have 

 been dropped for one reason or an- 

 other. 



By the courtesy of Mr. E. P. Van Duzee, of Buffalo, N. Y., the collec- 

 tions of certain of the groups made in New Jersey have been determined, 

 and he has also been good enough to look over the manuscript in these 

 groups and to give me suggestions as to the order of species and genera. 

 A very few species remain that have not been actually taken in the 

 State, but these are almost certain to occur, and besides these there are 

 undoubtedly many new species yet to be discovered and determined by 

 thorough collecting and study. 



All of the gentlemen who assisted me ten years ago have continued 

 their aid in one way or another. 



(8?) 



Fig. 32. Mouth structure of a plant- 

 louse: a, beak; b, the lancets; c, 

 tarsus; greatly enlarged. 



