HICKORY. LEAVES LITTLE HICKORY APHIS. 1G5 



most common upon the leaves of the hickory may be distinguished 

 by the following characters. 



The little Hickory Aphis {Aphis Caryrila) is pale yellow with whito 

 antennae which are alternated with black rings, 'the wings transparent and 

 without spots, their veins slender and pale yellow, the legs yellowish white to 

 their ends. Length 0.12 to the tips of the wings. The abdomen is depressed, 

 egg-shaped, its apex slightly narrowed and elongated. The antennae arc" 

 longer than the body, tapering, scven^jointcd; two basal joints as broad as' 

 long, twice the diameter of the following joints: third joint longest, slightly 

 thicker towards its base; fourth and fifth joints rather shorter than the third, 

 cylindric; two last joints together about equaling the fifth in length; the sixth 

 swelled at its tip into a long oval knob, the seventh more slender but not capil- 

 lary, shorter than the sixth; a broad black band at the apex of the third and 

 each of the three following joints. First vein of the fore wings straight and ! 

 almost transverse; second vein bent near its base, running first towards tho 

 apex and then turning rather abruptly and continuing straight to the inner 

 margin, more than twice as far from the first at tip as at base; third vein 

 arising from the stigma near its anterior end, and not from the rib-vein for- 

 ward of the stigma, as it does in the aphides generally, except those pertaining' 

 to this group, its base and its apex about the same distance from the second' 

 vein that this is from the first, forking rather foward of its middle, strongly 

 bent at this point, and from hence to its tip parallel with the third vein or but 

 slightly diverging from it, its tip a third nearer* that of the third vein than 

 this is to the second; second fork nearer the fourth vein at tip than to the first 

 fork, the triangular cell between it and the first fork with its three sides'equal; 

 fourth vein short and often nearly abortive, shorter than the second fork, 

 equally curved through its whole length, its tip much nearer that of the rib- 

 vein than that of the second fork; rib-vein very slightly diverging from tho 

 margin from the base to the stigma, curved from thence to its tip. Stigma 

 oval, about twice as long as wide, watery, sometimes tinged with yellowish. 

 A variety has the stigma dusky at its tip. Another variety {cost alls) has the 

 rib-vein coal black interrupted with whitish towards the stigma, which is 

 dusky, and black at each end. 



In addition to the species now described, four others occur 

 upon the under surface of the leaves of the hickory and walnut, 

 similar to it in size, form and general color, and as some of these 

 are frequently met with upon the same leaves with the preceding 

 they might be suspected to be mere varieties. Their spots and 

 maiks, however, are so clear and definite and the veins of their 

 wings are so dissimilar that we are obliged to regard them as dis- 

 tinct species. They may be named and briefly characterized as 

 follows. 



The little dotted-winged aphis {A. punctaldla) is much like the pre- 

 ceding in the color of its body, antennae and wings, but has black feet and a 

 black dot on the base and another on the apex of each of the veins of the fora 

 wings; the stigma is salt-white with a brown streak at each end; the second 



