CHERRY. LEAVES — APHIDIUS SPECIES. 137 



Opulus, var. Americnnuni). These stems are often covered with 

 lice, and the aphidiiis discovering them passes from one indivi- 

 dual to another, dropping an egg into the body of each. The 

 ■whole colony is ihiis destroyed by this parasite alone, ihe dead 

 swoi/len bodies of its victims remaining upon the stems crowded 

 togeiher as closely as they can stow themselves. I name this 

 species 



The Cranberry Aphtdius (Praon Viburnaphis). It is black and shining, with 

 the short sbdoniinal pedicel and ihe anterior legs wax yellow, their feet blackish at 

 the tip, the hind knees yellov\is.h; autennse 15-joiuted, the basal juiut wider than 

 long, the secimd nearly globular and slightly thicker than the foUowij g ones, the last 

 not larger than the one preceding it ; wings hyaline, "Jeins outer margin and stigma 

 black and shining. Length 0.075, wings expand 0.15. 



In the following species the veins are fewer in the fore wings 

 and do not form any closed cells in the disk; there is merely a 

 short robust curved vein from the inner angle of the stigma di- 

 rected towards the apex and ending abruptly, apd a vein running 

 obliquely from the mid-vein to the ouier margin forward of the 

 stigma. These pertain to the genus Trioxys. 



The latter part of June the present year the willows in this 

 vicinity were overrun, and many trees were almost defoliated by 

 an undescribed species of aphis. But in a short time these in- 

 sects were all destroyed by their enemies, and the under suiface 

 of the leaves w-ere thickly covered with Ihe swoolen grny bodies 

 of those which had been killed by jiarasites. These yielded the 

 following species : 



The Wrttow ApniDins {Trioxys Salicaphis). This is black and shining, with a 

 long elliptical abdomen, of a houej-jellow color at its base gradually passing to black 

 on its pos erior part; legs honey yfllow, ti[i3 of tlie fret and of the shanks and some- 

 times the outer sides of the thighs dusky; f elers honey yellow; anteniise black, 

 two-lhirds as long as the body, ISjointid, the third and following joints nearly 

 equal, cj lindrical, thrice as long as wide; stigma dusky. Length with the abdomen 

 in its usual arched posture 06. 



The Poplar ApniDins (Trioxys Popvlaphis) is black and polished, the abdomen 

 long elliplical and much narrower than the thorax, the basal sutures sulphur jelhjw; 

 legs sulphur yellow, the hind thighs lilack; antenna; n^arly as long as the hody, 

 15-j)iuted, third and following joints abimt equal, cylindiical, the last joitjt rather 

 longuf and thicker, oval with its ape.t rouuded; sti^'ma dusky, veins and outer mar- 



