440 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



Hornig, of Philadelphia, has collected similar galls on wild roses at 

 Bustleton, Pa., and Mr. E. L. Dickerson records them as occurring 

 on wild roses at Nutley, N. J. Mr. Geo. G. Atwood of the New York 

 Department of Agriculture writes that he has often seen abnormal 

 swellings of rose stocks, particularly Manetti and multi-flora. 



Considering the nature of the injury, it is evident that the cutting 

 and burning of infested stems is the only method of control. 



SOME COCCINELLID STATISTICS 



By H. E. EwiNG, Oregon Agricultural College, Corvallis, Oregon 



In the western part of Oregon plant lice are very abundant and de- 

 structive. This is especially true in the Willamette Valley, where 

 we find agriculture well advanced, the climate quite mild and vege- 

 tation luxurious. Among the various species found in the valley, 

 few, if any, are more destructive than Phorodon hu7nuli Schrank, the 

 hop aphis; Aphis hrassicce Linn., the cabbage aphis; and Aphis vihurni 

 Scop., an aphid found on several garden and other plants. 



We have in the valley also several well-known species of Coccinellidse 

 which usually do heroic work in checking the plant lice, but the writer 

 has noticed the absence of a few species of these beneficial insects 

 that are quite common in other sections of the country. Hence I 

 decided to introduce some of these into this section of Oregon, and, 

 as a preliminary step, have taken a few statistics on the relative 

 numbers of the different species of coccinellids found feeding on the 

 three species of aphids mentioned, and also feeding from the cell sap 

 secreted by stipule glands of vetch plants. Data, which gives us 

 some idea of the numbers of lady-birds present in any situation, and 

 especially data which gives the ratios of the numbers of individuals 

 of each species present and preying on any plant louse, are very ser- 

 viceable in helping estimate the value of a species after it has once 

 been introduced. 



In order to get the population statistics we collected all adult beetles 

 that were present in the following situations: feeding on Phorodon 

 humuli Schrank, on hops; feeding on Aphis vihurni Scop., on thistles; 

 feeding on Aphis vihurni Scop., on lamb's quarters; feeding on Aphis 

 hrassicce Linn., on kale; and, lastly, feeding in vetch, chiefly from a 

 cell sap secreted by special glands on the stipules of the leaves. 



The collections from hops were made August 19, 1913. We collected 

 all of the individuals found above our knees and up to as high as we 

 could reach. Later counts showed that 209 individuals were captured. 

 These were distributed among the different species as follows: Hippo- 



