22 (IRTIIOI'TERA OF NORTHEASTERN AMERICA. 



less hairy. The cerci of the female locust are 

 much smaller than those of the male, and in 

 other Orthoptera are often wanting. The ter- 

 guni or upper portion of the tenth abdominal 

 . nient is a triangular, often thick solid plate, 

 known as the mtpra-tDial plate. At the base 



dome S n of nS locus?:" f tllls P late aiul 1'^tillg UpOU it, a pail' of ]>1'O- 



rcY- P / a fu n rcuia- a J e sub- j^ctions, known as the fiii-nila, are usually 

 genital piate; s, 9, 10, present in the male. In certain genera of lo- 



ibdommal s e g m e n ts. * 



(After Hart.) custs the shape, size and relative position of 

 these afford valuable specific characters. Lying within the cav- 

 ity of the snbgenital plate, and occupying the space beyond the 

 tip of the supra-anal, there is in the Melanopli a structure covered 

 with a soft integument. This is known as the pallium and is 

 used to some extent in classification. 



The above constitute the more important external parts of the 

 locust, the characters of which are used in determining the mm" 

 and position of any member of the order Orthoptera. As will be 

 seen in the pages which follow, these different parts vary much 

 in size and in form, but the names given to them apply as well to 

 the members of one family as to another. By referring to the ac- 

 companying figures, a:ul by observing carefully the parts of the 

 specimen in hand, the beginner need have little hesitation in de- 

 ciding as to whether the description agrees with that specimen. 



THE RELATION OF OKTHOPTERA TO OTHER INSISTS. 

 All true insects can be separated into one or the other of two 

 great groups, based upon the kind of changes or transformations 

 which they undergo before reaching the adult or whued st-ige. 

 To one group the Mctabola belong those insects which undergo 

 what is termed a complete metamorphosis. In tlrs group there 

 are four distind si ages the egg, larval, pupal and imago in UK- 

 order named. No insect is hatched from the egg with wings, and 

 when an insect reaches the winged stage it is adult, and never 

 grows thereafter. Thus the gnals and midges are not the sons 

 and daughters of the larger flies, but are full in-own insects of 

 themselves, which are undergoing the fourth or last stage of their 

 lives. The second, the larval or worm-like stage, is the one in 

 which the insect of this group is eomiuonly the most injurious, 

 for tl-en it eats voraciously, and then is the only period of its life 

 when it grows in si?e. The pupal, or third stage, is usually a 

 quiescent one, the insect eating nothing and not increasing in size. 



