BEET AND SPINACH INSECTS 105 



The Spinach Aphis 



Myzus persicce Sulzer 



The spinach aphis is also known as the green peach aphis, 

 and as the common green-fly of greenhouses. It is found in 

 both Europe and America. In some locaUties it is the most 

 serious insect enemy of spinach and is sometimes injurious to 

 potato, tomato, eggplant, cabbage, turnip, radish, cauliflower, 

 cucumber, kale, mustard, beet, rutabaga, water cress, pepper, 

 horse-radish, celery, rhubarb, okra and lettuce. Eggplant often 

 becomes infested in the hot-bed before transplanting. Radishes 

 and rutabagas are sometimes attacked as soon as they come 

 up, the first pair of leaves being entirely covered on the under- 

 side by the lice. Such plants are badly stunted and sometimes 

 killed. The spinach aphis also attacks a number of weeds, 

 including pigweed, lamb's quarters, dock, shepherd's purse, 

 dandelion, sow thistle, lupine and wild mustard. It is often 

 found in greenhouses, where it infests the calla lily, carnation, 

 rose, violet, oleander and many others. It has also been re- 

 corded from tulip, pansy, hollyhock, tobacco, peppermint, rape 

 and several ornamental plants. It is also sometimes found in 

 the summer on apple, pear and lilac. 



The spinach aphis may pass the winter either in green- 

 houses or on its food plants out of doors, where the winters are 

 not too cold, or in the egg stage on the peach, plum, cherry, 

 apricot, sand cherry and choke cherry. In the last case, the 

 eggs hatch shortly before the buds burst in the spring and the 

 stem-mothers are ready to begin reproduction when the blossoms 

 appear. They are wingless and of a pinkish color. In the 

 second generation the plant-lice are for the most part wingless, 

 but instead of being pink, are pale yellowish green and usually 

 marked with three indistinct darker stripes on the abdomen. 

 In the third generation, most of the lice acquire wings. They 



