THE ENTOMOLOGIST 



Vol. XLV.] JUNE, 1912. [No. 589 



NOTES ON RHOPALOSIPHUM SOLANI, Kaltenbach. 

 By Fred. V. Theobald, M.A., F.E.S., Hon. F.R.H.S. 



I FOUND this aphis on potato-haulm at Wye in June and 

 July, 1911, but only a few apterous females and a single winged 

 female on June 28th. In February of this year a number 

 of seed potatoes were sent me from Folkestone, the sprouts so 

 badly attacked by aphis that they were all dying off, and the 

 thick honeydew formed by the " dolphins " had smothered the 

 tubers, which gradually turned brown and rotted away. 



On comparing the wingless females with those I found on 

 the potato-haulm in June and July of last year I found them to 

 be identical, and they agree exactly with Kaltenbach's descrip- 

 tion of Aphis solani (Mono. Pflanzenlause, p. 15). This is placed 

 as a synonym of Schrank's dianthi by Buckton. No damage has 

 been reported as caused by this aphis to my knowledge, but John 

 Curtis, in his famous work on Farm Insects, refers to aphis on 

 potatoes (pp. 68 and 428), and calls them Aphis rapre, or vastator* 

 Writing on the aphis in connection with potatoes he says : 

 ** That aphides will puncture the potato-leaves there can be no 

 doubt and so incline them to wither, but there is no proof of 

 them poisoning the plant and so causing the rot .... but 

 in no instance have I seen aphides on potatoes in sufficient 

 numbers to destroy the crop, or even to injure the produce." 

 He then lists the aphides he had found on the potato, namely. 

 Aphis rapes, Curtis; A. humuli, Curtis; A. persicce, Morren ; 

 A. fabce, Morren; and Schizoneura lanigera, Haussman ; and 

 refers to the last as being only an accidental visitor. 



The specimens I received from Folkestone were nearly all 

 apterous females ; on February 25th I found a few nymphs, and 

 on March 1st winged females commenced to appear, 



Kaltenbach only describes the wingless form, consequently I 

 describe in detail the alate female here. At the present time 

 (May 24th) they are still breeding on potatoes, alate forms 

 occurring irregularly. 



It may also be pointed out that in each of the six colonies 



-'• Aphis vastator, Smee, is considered by Schouteden to be RJiojialo- 

 sijihuvi dianthi, Schrank. 



ENTOM. — JUNE, 1912. 



