THE CANADIAN ENTOMOLOGIST 241 



As far as I have observed, the winter is passed in Britain 

 entirely in the egg stage on the apple and pear. 



The ova hatch in the beginning of April and by about the 

 20th of that month I have found numbers of apterous viviparous 

 females on the apple leaves. These apterse continue to increase 

 through May and towards the end of the month alatae commence 

 to appear. The earliest date I have of winged females is the 21st, 

 from Hailsham in Sussex. At Wye they have usually appeared 

 about the 29th, but in 1914 many occurred as early as the 10th. 

 These alate viviparous females migrate from the apple and pear 

 until the middle of June, by which time all seem to have disappeared. 

 Pergande and others traced this migration to corn and grasses in 

 America — the so-called Aphis fitchii of Sanderson — on the apple, 

 becoming the Aphis avencB of Fabricius on corn. In Britain I have 

 found the same. Apterae occur on oats, and more rarely barley, 

 from late June onwards. In 1911 1 found many as late as September 

 the 19th. By October 15th winged forms have been frequently 

 noticed on self-sown and wild oats, and in most years by the 20th 

 of that month all had flown from the corn back to the apple and 

 pear. But this cannot be general, for the return migrants to the 

 apple seem to appear gradually. Winged females have been for 

 many years noticed to appear on the apples over a much greater 

 length of time. It is possible that many come from wild grasses, 

 although repeated search has failed to reveal them on any kind of 

 grass in the south of England. The alate females on the apple 

 produce living young and these become the apterous oviparous 

 females and the alate males. These sexuales I have found in large 

 numbers year after year in October, and many continue to oviposit 

 late into November. The earliest oviparous females I have found 

 were in October 4th in 1911; the latest on November 15th in 1915. 

 Sanderson says that in America few eggs are laid before September 

 1st, but in these Islands I have never found any laid as early at 

 that. 



Miss Patch says "this species migrates from the apple and 

 certain other members of the Rose family to the oat and other 

 grasses for the summer." She also records it on Cratcegus at Orono, 

 Maine, U. S. A., in June, as alatae and pupae, the latter were green 

 with darker green longitudinal median and sub-lateral lines, 



