10 BULLETIN 276, U. S. DEPARTMENT OF AGRICULTURE. 



labeled M. pisi or its equivalent, and in no case has the true pisi 

 been found. On the other hand, Dr. Edith M. Patch had no diffi- 

 culty in getting this insect to live contentedly on shepherd' s-purse. 

 Theobald (11) lists shepherd's-purse (Bursa bursa-pastoris) as a 

 host, but later in his paper says: "Colonies now and then occur on 

 the shepherd's-purse, but I have never known them to survive any 

 length of time." The species reported for lettuce as M. pisi or a 

 variety of that species by Sanderson and o thers is an entirely different 

 plant-louse. Doubtless the species collected on nettle (Urtica) and 

 referred to this species by Oestlund is something else, and the same 

 can be said of the records of this aphidid from beet. 



In 1900 Dr. Chittenden reported tests made by Mr. Theodore 

 Pergande to colonize this insect on the following hosts, but with 

 negative results in each case: Sonchus asper, dandelion, shepherd's- 

 purse, Sisymbrium officinale, and dock. 



Dr. Edith M. Patch (1911) has reported a series of insectary host- 

 plant tests for M. pisi, which may be briefly summarized as follows : 

 Transfers from peas (Pisum sativum) to potato (Solanum tuberosum) , 

 to barley, wheat, oats, purslane (Portulaca oleracea), beets, and 

 squash were wholly negative; from peas to red clover partially 

 positive, and from peas to shepherd's-purse (Bursa bursa-pastoris) 

 positive. 



During the late summer of 1911 Mr. C. W. Creel, of this bureau, 

 and the writer conducted a number of transfer experiments, with 

 the following results: From red clover to cowpeas, cultivated buck- 

 wheat, wild buckwheat (Tiniaria cristata) , wild morning-glory (Con - 

 volvulus arvensis) , fleabane (Leptilon canadense) , pepper-grass (Lepi- 

 dium sp.), wheat, alfalfa, yellow sweet clover (Meliiotus officinalis), 

 and cinquefoil (Potentilla sp.), the results were negative; from red 

 clover to soy beans were partially positive and indicated that the 

 insect might survive and reproduce on young tender plants; from 

 red clover to red clover, garden peas, and white sweet clover (Meli- 

 iotus alba) the insect transferred readily and fed and reproduced con- 

 tentedly. In Chicago, 111., we found it breeding very abundantly on 

 tender succulent shoots of Meliiotus alba growing under greenhouse 

 benches. 



Theobald (12) attempted to colonize the species on willow, rasp- 

 berry, clematis, clover, and Lathyrus, but was successful with only 

 the two last-named plants. 



Mr. C. E. Sanborn (1904) reports this aphidid from rose, but in a 

 recent letter he writes: " Macros') pit um pisi has been correctly 

 recorded as being taken on rose. I doubt, however, if rose should 

 be considered as a regular food plant of this insect." We have 

 repeatedly attempted to colonize pisi on rose, but without success, 

 and there seems to be no reasonable question but that the specimen 

 collected by Sanborn on rose was a stray migrant. 



