662 EXPERIMENT STATION RECORD. [Vol.37 



plan for a spraying test. It is stated that, in general, infestation of orchards 

 iu western New York during 1916 was not severe. The oat aphis at the outset 

 outnumbered the rosy aphis and the apple aphis in most orchards, although 

 their comparative numbers varied locally. In relative abundance the three 

 species exhibit a seasonal succession or cycle, which, while probably varying 

 somewhat from year to year, appears to be fundamentally constant. 



"At Geneva activities began with the hatching of goodly numbers of the oat 

 aphis on April 22. A few rosy aphids were detected on the buds at the same 

 date, but this species did not reach maximum numbers until four days later. 

 The green aphis was the last species to hatch and began to emerge on April 26. 

 A.? during the preceding year, dwarfing of apples was chiefly the work of the 

 rosy aphis, although losses in fruit yields in this respect were rarely of serious 

 extent. 



" In experiments with the aphids all species attacked succulent tissues, as 

 blossom and fruit stems, tender leaves, and young apples. As a result of their 

 activities various distortions of apples developed. Severe infestation by A. 

 sorbi and A. pomi was attended in a number of instances by destruction of 

 entire clusters of apples. 



" In an experiment on Rome apples an application on May 1 of lime-sulphur 

 and nicotin sulphate at recommended strengths afforded efficient protection 

 from the oat aphis and the rosy aphis. The trees receiving the treatment were 

 also free from the green aphis until June, when there was a reiufestation of 

 the plat due to Invasion by winged migrants. Of 12 auxiliary experiments, 9 

 gave appreciable benefits from spraying. The remainder were inconclusive 

 because of slight infestation by the insects or excessive defoliation by apple 

 scab assisted in part by aphids." 



The reddish-brown plum aphis (Rhopalosiphum nympheae), W. M. David- 

 son (Jour. Econ. Ent., 10 {1917), No. S, pp. S50-35S, fig. l).—\ report of obser- 

 vations made in California, where R. nympheae is distributed in many of the 

 plum and prune districts. It is generally confined to a few trees in an orchard 

 and occasionally infests apricots and almonds; in the East it occasionally 

 attacks peaches. Though apparently of European origin and recorded from 

 many parts of Europe, it is known to occur from Maine to Virginia and in the 

 Central States and Colorado, as well as Ontario and Japan. 



Brief notes are given on its biology and habits and recognition characters, 

 including comparative measuronieuts. It is of especial interest in that it Is 

 double-hosted, spending the winter and spring on fruit trees and the summer 

 and early fall on a large variety of water plants. 



A paper on this pest by Patch has been noted (E. S. R., 34, p. 550). 



Tlie migratory habits of Myzus ribis, C. P. Gillette and Ti. C. Bragg {Jour. 

 Econ. Ent., 10 {1911), No. S, pp. 3SS-340, fig. jf).— It is pointed out that while 

 this aphid has long been known to leave the currant bushes during the middle 

 of the summer no one has definitely determined the alternate hosts. The 

 authors have repeatedly transferred the migrants from Ribes to Stachys and 

 Ijeonurus and the fall migrants from these plants to the currant and had them 

 take well, and thus feel safe in announcing these two genera, at least, as sum- 

 mer hosts of M. ribis. 



Little-known western plant lice, II, W. M. Davidson {Jour. Econ. Ent., 10 

 {1917), No. 2, pp. 290-297. fig. i).— These notes relate to Vacuna drynphUa, 

 which occurs on valley oak (Querctw lobata) at Walnut Creek, Cal. ; CalUp- 

 terineUa annnJata, which infests the foliage and shoots of imported birch 

 {Betula alba) in California and has been reported from other States; Aphis 

 neo-mc.ricana paeiflca n. var., which curls the terminal leaves of red currant 

 at Walnut Creek, Cal. ; and Myzus ribifolii n. sp., which curls and blisters the 



