88 MAINE AGRICULTURAI, EXPERIMENT STATION. 191I. 



transferred from peas to potato. All died without feeding or 

 producing. ( 43-08. ) 



(f) Aug. 12. A lot of 14 alate individuals (migrants from 

 peas) placed on potato. All died without feeding. No pro- 

 geny. (50-oS.) 



(g) Aug. 25. A lot transferred from peas to potatoes. 

 All died without feeding. No progeny. (50-08.) 



(h) Aug. 25. A lot of apterous adults and half grown 

 nymphs transferred from peas to potatoes. All died without 

 feeding. No progeny. (26-08.) 



From Shepherd's Purse {Capsella Bursa- past oris (L.) to 



Potato. 



(i) Aug. II. A lot of 5 alate individuals removed from 

 shepherd's purse to potato. These died without producing. 

 (43-08.) 



From Peas to Shepherd's Purse. 



(J) J^^ly 1 7- A lot of apterous viviparous individuals and 

 nymphs transferred from peas to shepherd's purse. In 15 

 minutes nearly all the aphides had already settled on the plants 

 and begun feeding. July 21, Old aphides dead. Stalks fairly 

 well covered with nymphs. July 31. Nymphs thriving though 

 of a yellowish color. Aug. 6. Mature apterous and alate 

 forms are present. These are hardly more than one-half the 

 size of the parent forms from peas. Aug. 25. This colony 

 still represented by alate and apterous forms feeding on shep- 

 herd's purse and producing. (26-08.) 



(k) July 21. A lot of mature apterous individuals trans- 

 ferred from peas to shepherd's purse. July 27. Mature indi- 

 viduals all dead. Good thrifty colonies of greenish yellow 

 nymphs present. Aug. ii. Seventeen winged forms present 

 and some pupae. These are much smaller than their parents 

 from peas. Five of these alate forms removed to fresh shep- 

 herd's purse where they at once settled and began producing, 

 and by August 25 had developed a few winged and mature ap- 

 terous descendants which were producing yellowish nymphs. 

 (43-08.) Aug. II. Five of the 17 alate forms (see the fore- 

 going Aug. 11) were transferred to young pea vines where they 

 settled, fed and produced. (43-08.) 



