INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 105 



Fig. 85. — The destructive pea aphis, Macrosiphum pisi (Kalt. ). All stages 

 of apterous and winged females. Enlarged three times. (Original) 



THE LARGE ROSE APHIS 



Macrosiphum rosw (Linnaeus) 



{Aphis rosw Linnaeus) 



(Fig. 86) 



Description. — This is a large aphis represented by two distinct 

 color varieties, the body of one bright green and of the other, pinkish. 

 The apterous forms have dark cornicles and dusky antennas and leg- 

 joints. In the winged forms the thorax and antennas are also dark 

 and there is a row of dark spots on either side of the abdomen. The 

 length varies from 1-12 to 1-8 inch. This species is readily distin- 

 guished from the other rose aphids by the large size, black cornicles 

 and the presence of the pink forms. 



Life History.— In California this species does not appear to lay 

 eggs, but to live upon the rose bushes throughout the year. It is 

 specially abundant during the early spring and early fall, being 

 less numerous in midsummer and midwinter. It attacks the young 

 buds and tender shoots and may greatly retard blooming or prevent 

 the development of perfect flowers. 



Distribution.— This species occurs throughout the State. 



Food Plants.— Wild and cultivated roses are attacked. 



Natural Enemies.— Natural enemies prey extensively on this pest. 

 The internal parasite, Lysiphlebus abutilonaphidis Ashm. 07 has been 

 reared from it in California. 



"Insect life, III, 61, 1890. 



