1917 ENTOMOLOGICAL SOCIETY. 47 



Mk. Ross: Judging from our results in the orchard the vast majority of the 

 eggs hatch before the buds burst. This year we sprayed as usual just before the 

 buds burst and while they were still compact; and we destroyed practically 100 per 

 cent, of the apliids. As we did not see any aphid.s on the sprayed trees afterwards 

 it led me to think that all or practically all the eggs had hatched before the buds 

 burst. In our insectary experiments, however, the eggs still continued to hatch 

 after the buds burst. 



Prof. Brittain : I came across a very curious thing in British Columbia. I 

 found a small number of aphids hatching when the snow was still on the ground 

 in March, on days when the sun was hot. In Nova Scotia I have found them 

 hatching outdoors until about the time the blossoms burst, though the vast majority 

 of them, as Mr. Eoss says, come out by the time the leaf buds burst. 



Mr. BiGGAR: Can you control the aphids in the greenliouse by spraying? 



Mr. Eoss : Yes, by using a nicotine extract, either by fumigating or by spraying. 



Prof. Caesar: Prof. Parrott has just come in and I believe is very much 

 interested in work with aphids. I wonder if he has any information about the 

 time of hatching of the eggs in relation to the different sprays. 



Prof. Parrott: One of my objects in coming to these meetings was to hear 

 some of the papers given' this afternoon, but I appear to have arrived too late to 

 hear some of them. I am very much interested in the discussion of what I take 

 ta be the paper dealing with Apple Aphids. I agree with what was said by one 

 speaker that by the time that the buds have broken and the leaves of the more 

 advanced buds are out from V^ to I/2 inch, the eggs of the three species, pomi, 

 sorhi and avence have hatched. I make this statement with considerable assurance, 

 because in two years' experience on one variety of apple we have been able to 

 combat all three species, that is to eliminate the insects by drenching the trees. 



Q. — What was that variety?- 



Prof. Parrott : Pome Beauty. As a matter of fact one of the papers that I , 

 want to present at the Association of Economic Entomologists is one dealing with 

 the control of the Eosy Aphis, as a problem for the extension entomologist. I 

 believe we can get as clean-cut results in spraying for sorhi, avence and pomi as for 

 almost any of the common insects on fruit trees. In our work we use several com- 

 binations of sprjiying materials, but the one we are recomraonding is composed of 

 lime-sulphur solution, using the stock material at the rate of 1 to 7 or 1 to 8 of 

 water, if scale insects are on the trees, and then to 100 gallons of the lime-sul])hur 

 we add % piiT^t of nicotine surplmtc. This is the spray we use on the Station 

 grounds. 



Prof. Caesar: Your 100 gallons are equal to about 80 gallons of the measure 

 which we use. 



Prof. Parrott: Yes, you use the imperial gallon measure. We have the 

 San Jose Scale* in nearly all the leading fruit growing sections of New York, and 

 so we use the combination to con)l)at the scale, apple scab and the rosy aphis. I 

 don't know liow the idea that one cannot rely on spraying at this time to combat 

 the rosy aphis was so firmly established in the minds of some entomologists. I 

 have been wondering if in breeding experiments by various workers, infested wood 

 was in all cases obtained from identical situations. A miscellaneous assortment 

 of infested wood, taken from trees subject to difTcrent conditions, might lead to 

 wrong inferences as to the length of the incubation period. At Geneva, Aphis 

 avence hatches first. As regards pomi and sorhi I don't think there is a great 

 difference in time of hatching. I must admit that until this year we did not know 

 the. nymph of the first instar of sorhi, and tlio time of hatching was determined 



