46 THE EEPOKT OF THE No. 36 



The Potato Aphis (Macrosiphum solanifoUi Ashmead). Dr. E. Patch 

 l^oints out ill her recent publication on the Pink and Green Aphis of the Potato, 

 that this insect has a very varied dietary ranging from grasses to comiDosites. In 

 view of this, it is not at all surprising that the aphid sometimes feeds on the apple. 

 I have two Ontario collections of it from this host. Mr. A. C. Baker, of the U. S. 

 Bureau of Entomology, also records its occui-rence on apple at Washington, D.C. 



Ontario collections: x41atai, apterous vivipany and nymphs — Guelph, 20.6.15; 

 Alate form — Vineland, Ont., .1.6.16. 



The Peach Aphis (Alyzus persicce Sulzer). This very common general - 

 feeder has frequently been found feeding on apple seedlings growing in the 

 Horticultural Experimental Station greenhouses at Vineland Station, Ont. Fall 

 migrants and their young have also been taken on orchard'trees. (Yinehmd, 1916). 



The Geeanium Aphis (Macrosiphum pelargonii Kalt). (?) Small colonies 

 of a large green Macrosiphum were frequently found this spring on some seedling 

 ajTples which we had growing in our greenhouse insectary at Yineland. 



I cannot be positive about the identity of this louse, but I think- it is Macro- 

 sphum pelargonii. It differs from typical pelargonii in having the abdomen of the 

 alate form ornamented with five transverse, broken, dark bands, but it is very 

 questionable if this slight difference has any specific significance. 



Peof. Beittaix r The study of aphids in Nova Scotia has been only a minor 

 problem with us. Our results have been very much the same as those of Mr. Eoss, 

 with the exception of course, of the differences due to climate. You have about 

 13 or 14 generations of pomi; we never have more than S" or 9. As for avena\ I 

 never saw it until this year, when it appeared in rather large numbers. This 

 spring I could not find a specimen of pomi, and if we had not kept eggs over from 

 last year we would not have had any at all to work with. Late in the summer, 

 however, winged forms began to appear in numbers and soon the insect was quite 

 numerous. Malifolice, with us, al=>p has 8 or 9 generations per year. The greater 

 number of the 3rd generation are migrant*. A small proportion, under certain 

 conditions, remain wingless and continue breeding on the apple throughout the 

 season, but their number is usually negligible. 



In 1915 a number of those which we kept in the insectary breeding upon the 

 apple became winged in the ?th generation. Tliese winged forms were the true 

 spring migrants, though it was September. 



In each generation we transferred some young aphids from the plantains 

 back to apples, and vice versa.' Hundreds of such experiments gave negative 

 results ; but in one case young from an ordinary wingless female of the 3rd genera- 

 tion on the apple, came to maturity on the plantain and became typical plantain 

 forms. 



In studying the natural control of these aphids we found that click beetles 

 preyed upon them and sometimes destroyed large numbers. 



Dr. Howaed: What species? 



Peof. Brittaust: Dalopius lateralis. 



Peof. Caesae : This comes right down to the matter that a number of us are 

 so much interested in, that is the control. Mr. Eoss spoke about the different 

 dates of eggs hatching of the different species, and I should like to ask him 

 whetlier all the eggs of all the important species are hatched by the time the buds 

 bfive begun to burst. 



