90 MAINE AGRICUIvTURAI, EXPERIMEJNT STATION. I9II. 



On Squash. 



August II, a lot of 15 alate individuals transferred from 

 peas to squash. They died within a few days without starting 

 colonies on the squash. Test repeated with 30 nearly grown 

 nymphs, all of which died within a few days. 



As a check against the foregoing tests, 7 lots under the same 

 conditions in other respects were transferred from garden peas 

 to sweet peas and from sweet peas to garden peas. All these 

 lots established healthy colonies and thrived. 



While failure to establish colonies under these conditions is 

 not a conclusive proof that M. destructor never feeds on the 

 plants refused in these tests, it is certainly strongly indicative 

 in that direction. On the other hand, there is no reason to 

 believe that any species of aphid will establish thriving colonies 

 on a plant in confinement that it would not accept in the open. 



EXPLANATION OF FIGURES. 



Figs. 59 and 60. M. solanifolii. Cornicle of male and tip of same, 

 showing reticulation. No. 22-07. 



Figs. 61 and 62. M. solanifolii. Cornicle of apterous oviparous fe- 

 male and tip of same, showing reticulation. No. 

 22-07. 



Figs. 62, and 64. M. solanifolii, pink variety. Cornicle of alate vivi- 

 parous female and tip of same, showing reticula- 

 tion. No. 106-06. 



Figs. 65 and 66. M. solanifolii, green variety. Cornicle of apterous 

 viviparous female and tip of same, showing reticu- 

 lation. No. 50-05. 



Figs. 67 and 68. M. destructor. Cornicle of apterous viviparous fe- 

 male and tip of same, showing imbrication. No. 

 19-07. Collected from garden pea. 



Figs. 69 and 70. M. destructor. Cornicle of alate viviparous female 

 and tip of same, showing imbrication. No. 19-07. 



Figs. 71 and 72. M. destructor. Cornicle of alate viviparous female 

 and tip of same, showing imbrication. No. 104-06. 

 Collected from sweet pea. 

 (Figures were drawn by Miss Charlotte M. King.) 



