850 EXPERIMENT STATION RECORD. [Vol.41 



(E. S. R., 34, p. 754). The food plants recoi'ded by tho author are apple, r»ear, 

 American crab apple, mountain ash, hawthorn, raid quince. Some varieties 

 of apples are more susceptible than others, the author having found Twenty 

 Ounce, Maiden Blush, King, Fall Pippin, Greening, and Baldwin to be the 

 most susceptible to injury. 



Investigations of the rosy apple aphis based upon roarings at Ithaca, N. Y., 

 during the seasons of 1914, 1915, and 1916 are i-eported, with references to 

 recent publications on the species by Brittain (B. S. K., 35, p. 853) and Baker 

 and Turner (E. S. R., 36, p. 356). The author supports the view of Sanderson, 

 who in 1901-2 (E. S. R., 14, p. 268; 15, p. 593) identified the American form as 

 A. sorbi of Kaltenbach, thus differing with Baker and Turner who consider it 

 to be a distinct form described by Fitch as A. malifoUw. The fact that this 

 species did not assume the status of an important apple pest in the United 

 States until late in the nineteenth century is shown to be due to the fact that it 

 must have an abundance of its summer host plants, the introduced European 

 narrow- leaved and broad-leaved plantains {Plantago lanceolato and P. major), 

 near at hand. The first real work on its bionomics was reported by Sanderson 

 in 1901-2. More recent work has been reported by Britton in 1910, Brittain in 

 1915, and Baker and Turner in 1916. 



Rearing experiments and field observations by the author show that P. 

 lanccoTata is the preferred summer host plant, and at Ithaca at least it is 

 essential to the continued i-eproduction of the species during the summer. 

 Breeding experiments on P. major were never successful for more than two or 

 three generations, the line dying out sometimes very quickly, which results 

 agree with those obtained by Baker and Turner, although Ross in 1915 and 

 Brittain report very successful breeding exiDeriments on P. major. The author 

 points out that there is a remarkable parallelism between the spread of P. 

 laiiceolata and the spread and increase in destructiveness of A. sorhi. 



The author's studies of the European grain aphis relate only to it upon the 

 apple, its primary host. Studies of it on other hosts have been made by a 

 number of writers, including those of Davis (E. S. 11., 31, p. 753). At Ithaca 

 only three generations are normally produced on the apple, and the winged 

 migrants have practically all left by early June for summer host plants, which 

 include a large number of grasses and cultivated grains. At Ithaca the fall 

 migrants begin to appear on apple and hawthorn about the last week in 

 September. 



Data relating to the reproduction of ^4. pomi and ^1. sorbi are presented in 

 detail in tabular form, and charts are given showing the reproductive capacity 

 of the generations for 13 generations of ^1. poini and 10 of A. sorbi. Illustra- 

 tions in colors are given of the first instar of the stem mother, of the mature 

 stem mother, the winged viviparous female, mature oviparous female, mature 

 male, spring migrant, returned migrant, and mature oviparous female. The 

 effect of the three species upon the apple tree and its fruit is pointed out. 



A bibliography of 54 titles is appended. 



Recent studies of the eggs of the three species by Peterson at the New Jer- 

 sey Stations have been noted (E, S. R., 41, p. 253). 



Miscellaneous aphid notes, I, J. J. Davis {Canad. Ent., 51 (1919), No. 10, 

 pp. 228-234, fiys. 6). — The genus Heteroneura is erected for Aphis setarice, and 

 two species are described as new, namely, A. cuscutw and Macrosiphuin ribiel- 

 lum. A. cuscutw was collected at Kaysville, Utah, on dodder (Cuscuia cpitfiy- 

 mum) growing on alfalfa. 



Fitcli's thora leaf aphis, A. C. Bakee [Proc. Biol. Soc. Wash., 32 (1919), pp. 

 185, 186). — The author finds that Aphis cratwyefolite of Fitch belongs to the 



