PEACH INSECTS 289 



days, and then enter the ground to the depth of a few inches, 



where they transform to pupse inside a tough brownish cocoon. 



The adult sawflies emerge in about nine days. The whole 



life cycle is completed in less than a month and there are several 



generations annually. Doubtless this insect can be controlled 



by the same measures as are recommended against the pear 



slug. 



References 



La. Agr. Exp. Sta. Bull. 48, pp. 142-145. 1897. 

 U. S. Bur. Ent. Bull. 97, Pt. V. 1911. 



The Black Peach Aphis 



Aphis persicce-niger Smith 



This dark brown or black plant-louse is a serious enemy of 

 the peach in certain parts of the Eastern states, particularly 

 in Delaware, Maryland, New Jersey and Virginia. It occurs 

 in Colorado and California and has been reported from Ontario, 

 Canada. It is a native insect, and the wild plum was probably 

 its original host plant. 



This plant-louse feeds throughout the year upon the roots 

 of the tree and during spring and early summer is also found 

 upon the tender twigs and leaves. It breeds agamically all the 

 year round, and no males or eggs have been found. Only the 

 wingless forms occur upon the roots, where they breed freely, and 

 are to be found at all seasons of the year, often a foot or more 

 beneath the surface even in stiff clay soils, although sandy soils 

 are preferred. Early in spring, as soon as the buds begin to 

 swell, some of these root forms make their way to the surface 

 and establish colonies on the new growth. They increase 

 rapidly, so that in a few weeks the tender twigs and even the 

 leaves become entirely covered by masses of the dark bro^vn 

 or black Hce. As their feeding quarters become crowded winged 

 forms (Fig. 248) develop and fly to other trees, where they es- 



