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MoEDViLKO (A.). fopoxOBan TJlfl. [The Pea Aphis.] — « TpyAbi Bwpo 

 no QHTOMonorin YMeH. Kom. fjiaB. Ynpae. 3. h 3.» [Mevioirs 

 of the Bureau of Entontologi/ of the Scientific Committee of the 

 Central Board of Land Administration and Agriculture\ Petrograd, 

 vol. viii, no. 3, 1915. Second, revised and enlarged edition, 54 pp., 

 2 plates, 4 figs. 



Pisum sativum is attacked by only one species of Aphid, viz., 

 Acyrthosiphon [Macrociphum) fisi, Kalt., and there is no doubt that 

 all descriptions of Aphids observed on peas deal with one and the same 

 species. Kaltenbach, who was the first to describe it, evidently did 

 not fully realise the difference between this species and those found 

 on Geum urhanum and Sjnraea ulmaria, as he includes both these in 

 the list of its food-plants. Aphis onohrychis, found and described by 

 Boyer de Fonscolombe in 1841 on Hedysarum onohrychis, is also the 

 same species. Kaltenbach treated as a synonym of Ajjhis pisi, 

 Aphis idmariae, Schr., found on flower stems of Spiraea (Filipendida) 

 id?naria and consecjuently some of the later authors called the pea 

 aphis, Siphonophora idmariae, Schr. Professor Cholodkovsky has, 

 however, pointed out that Aphis idmariae is quite a distinct species. 

 The species discovered by Cholodkovsky on Spiraea uimaria is, 

 however, a species of Macrosiphum, while there is no doubt that 

 Schrank had before him a species of Aphis, and therefore the author 

 proposes to call the species of Cholodkovsky, found on the flowers 

 and beneath the leaves of Spiraea uimaria, Macrosiphum cholod- 

 kovshyi. The Aphid found on Caragana arborescens (Siberian pea-tree) 

 has also been confused with the pea aphis, but is a distinct species, 

 Acyrthosiphon caraganae, Choi. The author has erected the genus 

 Acyrthosiphon for the pea aphis and its allies, and he describes and 

 figures its characteristic features. All the species of the genus 

 Acyrthosiphon live chiefly on grasses, preferably on their stems, less 

 frequently underneath the leaves ; only a few species such as A. cara- 

 ganae, breed on bushes. No Aphids with a long cauda are visited by 

 ants, and as this fact deprives them of some protection ofi'ered by 

 the ants, they have adopted some other devices for defence, such as 

 dropping rapidly when disturbed ; protection is also afforded by their 

 colour and the presence of long and partly movable tubercles producing 

 a waxlike substance, which clogs the mandibles of an enemy. A key 

 is given to the species of Acyrthosiphon, which, in addition to A. pisi 

 and its subspecies, includes A. orientale, Mordv. ; A. norvegicum, 

 Mordv. ; A. kamtshatkanum, Mordv. ; A. caraganae, Choi. ; 

 A. vassiUevi, sp. n., from the underside of leaves of pumpkins in 

 Turkestan ; A. emelianovi, Mordv. ; A. gossypii, Mordv., from cotton, 

 and A. gossypi paczoskii, subsp. n., from stems of Lepidium perfolia- 

 tum ; A. skriahini, Mordv., from Malva neglecta; A. duhium, Mordv., 

 from Papilionaceous plants in the delta of the Volga ; A. loti, Theob. ; 

 A. cyparissiae, Koch, and A. navozovi, Mordv. The various stages 

 are ctescribed, including the stem-mother, the summer wingless 

 parthenogenetic female, the autumn winged parthenogenetic female 

 and the sexual forms. A comparison of the specimens of wingless 

 and winged parthenogenetic females, collected from Ononis hircina in 

 Volhynia and Cherson, with those taken from peas, have demonstrated 

 the fact that Siphonophora ononis, Koch, is also a synonym of 



