550 



(green apple aphis), A. malifoliae (rosy apple aphis), A. avenae (oat 

 aphis) andEriosoma lanigenmi (woolly aphis), are noxious ; the remain- 

 ing six, A. bakeri (clover aphis), A. brevis (long-beaked clover aphis), 

 A. sp. near gossyjpii, Macrosi'phum solmiifolii (potato aphis), Myzus 

 persicae (peach aphis) and ? MacrosipJmm pelargonii (geranium aphis), 

 are believed to be of little or no economic importance. 



It is pointed out that the correct name for the rosy apple aphis 

 is A. malifoliae, Fitch [see this Review, Ser. A, v, p. 49]. 



In the discussion that followed Prof. Brittain stated that there 

 are never more than 8 or 9 generations of A. pomi in Nova Scotia, 

 while in Ontario there are 13 or 14 a year. A. malifoliae also has 

 8 or 9 generations a year in Nova Scotia, the greater number of the 

 third generation being migrants. In studying the natural control of 

 these Aphids it has been found that they are preyed upon by the 

 Elaterid beetle, Sericus (Dolopiits) lateralis. Prof. Parrott stated that 

 good results in sprapng for A. sorbi, A. avenae and A. pomi could be 

 obtained by using a combination spray to combat the San Jose scale 

 {Aspidiotvs perniciosus), which is present in nearly all the chief fruit- 

 growing parts of New York, as well as apple scab and the rosy aphis. 

 The mixture is composed of lime-sulphur solution, using the stock 

 material at the rate of 1 to 7 or 1 to 8 of water, with | pint of nicotine 

 sulphate added to 100 U.S. gals, of the lime sulphur. 



The author further stated that the winged forms of A. malifoliae 

 that migrate from api^le to plantain are viviparous, as also are the 

 return migrants, though the sexual females which arise from the latter 

 are oviparous. He was unable to say whether this migration was 

 necessary to the species or whether it stimulated sexual development, 

 since under experimental conditions this species had been induced to 

 complete its cycle on the apple, while A. avenae, in which the migra- 

 tory instinct was more strongly developed, could not be induced to 

 remain on apple. 



Bated (A. B.). An Historical Account of the Forest Tent Caterpillar 

 and of the Fall Webworm in North America. — 47th Ann. Rept. 

 Entom. Soc. Ontario for 1916, Toronto, 1917, pp. 73-87, 1 map, 

 6 charts. [Eeceived 12th October 1917.] 



This paper reviews the occurrence, local ravages and general out- 

 breaks of MaJacosoma disstria (forest tent caterpillar) and Hypliantria 

 ctinea (fall webworm) respectively in the eastern, central and western 

 regions of N. America from the year 1770 to the present day. 



SwAiNE (J. M.). Some Features of Interest in Connection with our 

 Studies of Forest and Shade Tree Insects. — 47th Ann. Rept. Entom. 

 Soc. Ontario for 1916, Toronto, 1917, pp. 95-106, 3 plates. 

 [Received 12th October 1917.] 



There is apparently little hope of obtaining an effective control for 

 Trachykele sp. (the western cedar borer), an insect that breeds freely 

 in the heart-wood of living forest trees, although burning the slash 

 from infested trees before the early spring should materially reduce 

 its numbers. Galerucella decora (willow leaf beetle) usually feeds on 

 willows and poplars, and spraying wnth strong kerosene emulsion will 



