December, '10] DAVIS: ILLINOIS APHIDID.E 493 



Thomas makes no mention as to the type locality of this species, but 

 supposedly it was collected by him in Illinois. 



Toxoptera graminum Rond.: Hunter, Bull. Univ. Kans., Vol. IX, 

 No. 2 (1909), 221 pp., 66 figs., 9 pis., 3 col. pis. Ordinarily this species 

 does not become injuriously abundant in Illinois, but occasionally it 

 damages grain in southern and parts of western Illinois. First re- 

 ported by Forbes. 



*Hyadaphis pastinacoe Linn. : ? Monell, Bull. U. S. Geol. and Geog. 

 Surv., Vol. V, No. 1 (1879), pp. 26-27. {Rhopalosiphum salicis). 

 Weed, Trans. Amer. Ent. Soc, Vol. XX (1893), p. 297 (H. salicis). 

 This species I have taken on Zizia aurea, garden parsley, and Salix, 

 in Illinois. On the parsley they became so abundant as to notice- 

 ably damage it. According to Schouteden the following synonyms 

 have already been recognized, — aegopodii Scop., caprece Fabr., cicutcB 

 Koch, umhellatorum Koch: It is with some hesitation that I add 

 another species {H. salicis Monell) to the already long synonomy. 

 All of the Hyadaphis which I have found on Salix agree well with 

 the descriptions of pastinacce and with the specimens taken on 

 Zizia aurea and parsley. Also Mr. Monell has kindly made a careful 

 examination of the type slides and in a letter dated October 14, 

 1910, he says, "I have just looked at it [type slide of H. salicis, 

 collected June 15, 1878] under a ^ objective, and I cannot see 

 the tubercle [referring to a small acute tubercle on the dorsum of 

 the penultimate abdominal segment and projecting caudad, a charac- 

 ter which appears to be found in no other species of this genus] on 

 specimens mounted back up but luckily one specimen is mounted 

 sideways and I can see the 'horn' plainly. My recollection is this 

 was quite a common species in 1878-1879, but now we seem to 

 find only isolated specimens in colonies of the Ch. viminalis." In 

 an earlier letter (October 6, 1910) Mr. Monell gives some interesting 

 compiled data which I copy verbatim. "This S. caprece [ = pastinacoe} 

 on willow and Umhelliferce does not seem to be an 'alternation' of 

 food plants as witness these dates — 



On willow. 



In April, Kaltenbach's Monograph. 



June 11, '77. Willow, Pergande notes, St. Louis, Mo. 



June 15, '78. 150o St. Louis, Mo. Old tjT^es of Rh. salicis. 



May 25, '86. 341x St. Louis, Mo. 



Oct. 1, '10. Collected by Davis at St. Louis, Mo. [winged]. 



[Aug. 4, '09. Oak Park, 111. Apterous only.] 



On Umhelliferce. 



May 22, '07. On Thaspium, 539x, St. Louis, Mo. Apterous only. 

 June 19, '07. On Heradeum, 548, St. Louis, Mo. Apterous only. 

 July 1, '10. On garden parsley, 830x, Chicago, Davis, Apt. and winged. 

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