90 ENTOMOLOGICAL SOCIETY OF ONTARIO. 



Mr. Oraig described the severity of the winter of 1896-97 in Canada, when there was 

 severe cold but little snow. This year, throughout southern Canada, plant-lise were 

 present in tremendous numbers on apple, plum, cherry, and other trees. 



In the general discussion which followed, the fact was brought out that plant-lice had 

 been particularly abundant throughout Canada and the United States during the past 

 summer. 



Mr. Howard pointed out the fact that this abundance was probably due to the wet 

 weather of late spring and early summer, which had checked the feeding and multiplica- 

 tion of the natural enemies of the plant-lice. 



Mr. Minot stated that in the vicinity of Milton, Mass., injurious insects had been 

 quite scarce during the past summer; fewer potato beetles had been noticed than for many 

 years, while rose-chafers and tent-caterpillars were equally scarce. He also had noticed 

 the great abundance of plant-lice early in the season, but after the extreme hot weather 

 of the first week of July their numbers greatly diminished. 



Mr. Howard emphasized the fact that hot weather played a very important part in 

 controlling plant-lice. He cited an instance where, several years ago, Mr. Barrows had 

 called his attention to the extraordinarily large number of plant-iioe upon certain shade 

 trees of Washington, D.C. The following day the temperature reached the maximum of 

 100° F., and as a result the plant-lice disappeared like magic. 



Mr. Ashmead called attention to the fact that the family of plant-lice was not 

 extensive in the tropics, thus supporting the theory previously discussed. 



Mr. Barrows stated that the condition in Michigan regarding plant-lice was probably 

 tfhe same as that in Canada. He was of the opinion that the great abundance of these 

 insects in Michigan during the past summer was probably due to the large number pres- 

 ent last year. While examining the orchards for the San Jose scale last winter his 

 attention was attracted by the remarkable quantities of plant -lice eggs deposited on 

 young nursery stock and on orchard trees. So numerous were these eggs in some cases 

 that the trees had the appearance of being varnished. His experience agreed with that 

 of Dr. Howard, that hot weather was a most important factor in controlling the increase 

 of plant-lice. Referring to Mr. Howard's first paper, Mr. Barrows fpoke of the general 

 lack of appreciation of the value of such experiments as those described and the lack of 

 careful observations concerning the relation of temperature effects to the increase or 

 decrease of injurious insects in connection with the abundance or absence of their natural 

 enemies. A man might have observed a decrease or increase over the normal of the 

 temperature for the winter of 1895-96 and arrived at the conclusion that this had been 

 the chief factor in checking the outbreak of the Orgyia caterpillar, thus neglecting to 

 take into account the action of the parasites. Tnere was great need for careful and 

 exhaustive observations whenever temperature effects are associated with the abundance 

 or scarcity of any insect. 



Mr. Webster called attention to the fact that the great numbers of aphides in Ohio 

 nurseries this year had seriously injured a large quantity of joung, rapidly growing 

 stock. 



An abstract of " Notes on Certain Species of Coleoptera that Attack Useful Plants," 

 by F. H. Chittenden, was read by the Secretary pro tern. These notes treated chiefly 

 of the food plants and habits of certain Chrysomelids. " An Experience with Paris 

 Green," by T. D. A. Cockerell, was also read by the acting Secretary. 



A letter from Miss E. A. Ormerod called particular attention to the fact that the 

 house sparrow had been very abundant and very obnoxious in certain parts of England, 

 and it seemed probable that some legislation or public measures would need to be adopted 

 to control this bird. The arrival from Tripoli of a cargo of wheat, badly infested by the 

 Angoumois moth, was recorded and reference made to the occurrence in injurious numbers 

 of Xylehorus dispar at Toddington. 



Prof. P. H. Rolfs presented notes on " A Fungus Disease of the San Jose" Scale." 

 This disease seems to be confined to the southern part of the United States, but is very 



