lo Bulletin 328 



injury, and there was an epidemic of fire blight. As seen by 

 the writer, there is no necessary connection between the epidemic 

 and the aphis, l)ecause the aphis was worse in 1915 and 191 7 

 than in 19 16, while the fire blight was limited in these two years. 

 In 191 5 Mr. John Barclay, of Cranbury, estimated the damage 

 done his orchard l)y apple aphis at $40 an acre. This occurred 

 in spite of the practice of w^hat was then thought to be careful 

 spraying for the insects. 



Life History and Habits 



All species pass the winter in the egg stage attached to the 

 l)ark of the twigs and smaller branches of the trees. The green 

 apple aphis appears to be partial to water sprouts, while the eggs 

 of the other species are likely to be found in depressions about 

 pruning, bud and fruit scars, or thrust almost or quite out of 

 sight between the bud and stem. 



The oat aphis w^as the first species to hatch at New Brunswick 

 and vicinity in the spring of 19 17. They w^re discovered on 

 the buds on March 31. Then (about April 12 to 14) came the 

 rosy aphis and green apple aphis almost coincidently. The dif- 

 ference in the time of hatching of the first two species was suf- 

 ficiently great for the oat aphis to have hatched and reached the 

 buds, and to have been destroyed by insecticides, while the rosy, 

 at that time in the egg stage, hatched later and seriously dam- 

 aged the foliage. 



The oat aphis reached the buds as they were swelling and 

 before any leaves were yet projecting, while the rosy came on 

 only after the tiny leaves w^re projecting from forward buds 

 like squirrel ears. The rosy aphis hatched at the same stage of 

 bud development as in 191 6. Inasmuch as the experience rela- 

 tive to time when the rosy aphis hatches differs in different parts 

 of the country, the writer will quote from his notes in 1916: 

 "Early in the forenoon Mr. Barclay called me over the telephone 

 and told me that the aphis began emerging in his orchard in 

 enormous numbers on the preceding afternoon (April 15, 1916). 

 The day was clear and warm and the personal examination, 

 which I made later in the morning, showed aphis present every- 

 where in large numbers. Nearly every flower bud on unsprayed 

 trees showed at least one-half dozen specimens, while the buds on 

 trees treated with 'Scalecide' or with winter-strength lime-sulfur 

 in dormancy rarely exhibited more than one specimen to the bud. 

 * * '■'''- At this time the most advanced cluster buds showed 

 the first green leaves separating from the cluster, and the young 

 leaves projecting from the opening l)uds like squirrel ears were 



