316 AMERICAN POMOLOGY. 



Mysia I5-punctata / the larva is a clear white, the mid- 

 dle of the back tinged with red, and two or three black 

 spots on each segment nearly a hundred species of Lady- 

 birds are found in this country. The perfect insect, as 

 well as the larvae, feed upon Aphides, and instead of being 

 destroyed, they should be cherished and encouraged. 



Besides these, there are other inveterate enemies of the 

 pi ant-lice in the Syrphidoe, which are two- winged flies, 

 resembling the common house-fly, but handsomer. They 

 deposit their eggs where Aphides exist ; the maggot, 

 which hatches from these, seizes upon the first Aphis that 

 comes within his reach, and sucks its fluids. A medium- 

 sized worm will consume a hundred lice in an hour. They 

 are always found in a colony of Aphides* 



Aphis prunifolift, or the Plum Leaf-louse, is black, with 

 pale green abdomen. It is found on the under side of the 

 leaves, which become wrinkled and distorted. It is not 

 so abundant as some other species, but its habits are 

 similar. ** 



Aphis cerasi, (Fabric^ or the Cherry Plant-louse, is 

 very common, very numerous, and very black. They ap- 

 pear with the first expansion of the leaves, and continue 

 or are renewed when destroyed, and remain until mid-sum- 

 mer, when they generally disappear. Their numbers are 

 almost incredible, and they give a young cherry tree a 

 wretched appearance. On the under surface of a small 

 leaf, three-fourths of an inch long, Mr. Fitch counted one 

 hundred and ninety lice, on one. side only of the mid- 

 rib. Their natural- enemies come to the rescue to check 



* Kept, cit., p. 100. 



* * Kept. cit. p. 122. 



