October, '10] GILLETTE: PLANT LOUSE NOTES 405 



Aphis cephalanthi Thos. From button-bush, Cephalanthus occi- 

 dentalis, at Webster, Mass., Figs. 18 and 19. 



Aphis samhuci L., Figs. 20 and 21. What seems to be the typical 

 form of this species was taken by Mr. Bragg at Webster, Mass., on 

 Samhucus sp. 



Aphis cerasifolii Fitch, Figs. 22 and 23. Taken at Webster and 

 Geneva, where it was very abundant on the eastern choke-cherry, 

 Prunus virginiana. This is a very common louse, curhng the termi- 

 nal leaves on limbs and sprouts of Prunus pennsylvanica wherever I 

 have found this cherry growing in Colorado to an altitude of 8,000 feet. 



Aphis bakeri Cowen. Taken at Corvallis and Portland, Ore., on 

 red clover. We have taken this species from red clover or apple about 

 Fort Colhns, Denver, Rocky Ford, Canon City, Delta, Paonia, and 

 Grand Junction in Colorado. Figs. 24 and 25. 



Aphis brassicce L. Taken at Corvallis, Ore., only, on rape. A very 

 common species on both east and west slopes in Colorado where it is 

 a serious pest on cabbage, cauliflower and rape. Figs. 26 and 27. 



Aphis maidi-radicis Forbes. At Webster, on corn and at Washing- 

 ton on ox-eye daisy, Chrysanthemum leucanthemum. About Fort 

 Collins this is a fairly common species on corn roots. Have also taken 

 it on roots of Helianthus and on rhubarb. Figs. 28 and 29. 



Aphis rumicis L., Figs. 30 and 31. Taken at Chicago on Rumex 

 crispus (yellow dock), Lansing and Detroit on garden beets, Geneva 

 and Washington, D. C, on burdock {Lapjm officinalis), Corvallis and 

 Oregon City on burdock, yellow dock and Lamb's quarter (Chenopo- 

 dium), and at Seattle on Lamb's quarter. 



The white spots and dashes upon the abdomen of the pupae, and 

 often of the apterous viviparse of this black louse are quite character- 

 istic and yet there is much danger of its being confused with closely 

 allied species. Figures 30 and 31 are from alate lice taken from 

 Rumex crispus at Chicago, June 23, 1909, and which agree well in 

 structure with examples of this species sent me by Prof. T. D. A. 

 Cockerell from Sussex, England, taken upon Dipsacus sp. and others 

 labelled " A. rumicis " from H. F. Wilson, taken at Washington, D. C, 

 Nov. 21, 1908, on Rumex sp. 



Aphis atriplicis L. Taken at Portland, Mich., Geneva, New York 

 City, Washington, and Corvallis and Hood River, Ore. This is a very 

 abundant species generally distributed in Colorado upon both sides 

 of the mountains and up to fully 7,000 feet altitude. This species was 

 described by Mr. Cowen, in Bull. 31 of the Colorado Experiment 

 Station as A. chenopodii. Figs. 32, 33 and 34 are from examples taken 

 at Fort Collins, on Chenopodium, June 12, 1909. 



Aphis cornifolice Fh., Figs. 35, 36, 37, and 38. Taken at Portland, 

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