bronzed reflection on the dorpuni, the under side l:)ein<; fjenerally paler and covered 

 Avitli a more or kv s distinct pruinons secretion. Otherwise they are hke the spring 

 migrants. 



Sexual female . — The mature sexual females (fig. 1, }> and /') measure from 1.6 to 1.8""° 

 in length; they are oval and almost equally tapering toward each end. The antennse 

 are short, about half the length of the 1)ody, and five-jointed, the spur being the 

 longest, with the third joint somewdiat shorter; all of the joints are plain. The 

 nectaries are short, and do not reach to tlie end of the liody; they are usually taper- 

 ing, cylindrical, or rarely slightly clavate; the tail is still shorter, its basal half 

 rather broad, with the s'ides parallel, while the terminal part is broadly triangular 

 and covered with minute sharp points. The posterior tibiae are more or less dis- 

 tinctly inflated and j^rovided with numerous circular, sensorial pores. The color of 

 these sexual females varies more or less; some are of a \Yx\e, dirty orange, marked 

 with irregular dusky spots, while others are still darker, spotted only along the 

 sides; iiuun' are entirely of a greenish dusky color, often exhibiting in fnjnt of the 

 nectaries a lateral row of small, oval, whitish spots; all are, however, provided with 

 a reddish shading arouml the base of the nectaries. The eyes are brown, the anten- 

 nae, legs, and tail dusky and the nectaries black. Each of them contains from two 

 to four or five eggs. These females, either before or after copulation, forsake their 

 position on the leaves or branches and commence to travel restlessly about, \n order 

 to select a secure spot for depositing their eggs, when, especially <luring warm days 

 of Oc'tol)er, every part of a tree may be seen covered with them, either in copula or 

 engaged in depositing their eggs. 



Male. — The males (fig. 1, fZand c) as a rule are generally smallei- tlian the migratory 

 females; their expanse of wings ranges between 5.4 to 7'"'" and the length of their 

 body between 1.2 to 2""". The general appearance of the male is very similar to that 

 of the migratory female, thougli the abdomen is narrower and the last two segments 

 more protruding. The general color oi the abdomen is either orange or greenish 

 yellow, though fre(|uently there is a more or less defined, dusky, median line, ter- 

 minating, between the nectaries, in a dusky si)ot. The antenna3 are generally 

 somewhat longer and stouter than in the migratory female; joints three and four 

 more strongly and more densely tuberculated and the spur longer than joint three. 

 The genital armature consists of two elongated, triangular lobes or claspers, rounded 

 at the end and covered with erect hairs, between which projects a cylindrical sheath, 

 containing the colorless and flexible organ, which frequently ma}- be observed 

 extruding in a hook-like fashion. 



Before maturity of the females the males rest motionless on the under side of the 

 leaves from which they draw their nourishment, though no sooner have the females 

 cast their last skin than they l)ecome very nervous and restless and walk briskly 

 about on the l)ranches and the trunk on which the females have congregated, so that 

 frecjuently thousands of ))oth sexes may be observed, among them many in copula, 

 and often several males may be seen paying attention to the same female. 



All of those destined to produce a sexual generation the following fall remain and 

 multiply on grains and gras.ses, though producing at certain times a luigratory form 

 to enable them to sjtread and to protect themselves against destruction over a large 

 area of the country, during wdiich time for a greater or less extent certain external 

 changes take place, the extreme forms of which may easily pass as distinct species, 

 when toward the second fall they return again to the original form. 



NATURAL ENEMIES AND PARASITES. 



Fitch, in hi.s admii-able work on the apple louse, refers to the larvie 

 of various aphis lions (Chrysopa) and ladybirds (Coccinellidre) as 

 being ^'ery effective in keeping- the aphides in check, whereas in con- 



