Circular 107 



Pink and Green Aphis of the Potato 



{Macrosiphum solanifolii Ashm.) 

 The pink and green aphis of the potato passes the winter as an 

 egg on rose bushes and probably upon various weeds. While no rec- 

 ords of the spring habits are available for New Jersey, in Maine it 

 has been found commonly upon rose plants. The first generations 

 occur on relatively non-economic plants and it is only as the season 

 advances and winged forms are produced that the lice migrate into 

 the potato and tomato fields. 



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JSP 









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1 



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2 









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Fig. 1 



Pink and Green Aphis of the Potato and Tomato 



1— Adult winged female; 2 — Immature female; 3 — Adult wing- 

 less female 



When they first arrive they are few in number and pass unno- 

 ticed by the grower. At this time here and there through the field 

 will be found on the underside of a leaf a winged louse measuring 

 about % inch in length with several very small white young stand- 

 ing near her. At this time the plant has suffered no appreciable 

 harm and, if prompt steps are taken to destroy the incipient infesta- 

 tion thus established, the crop is likely to escape all appreciable in- 

 jury. 



With favorable (cool) weather the lice reproduce rapidly. At 

 this time all the lice are females and a single specimen can produce 

 50 young in 2 weeks. In 2 weeks after birth each of the young 

 reaches maturity and begins bearing young on her own account. 



