18 



The invigorating effects of warmth upon hibernating insects have often been 

 noticed. In England, in sheltered woodland nooks, on unusually bright days, 

 even as late as November, I have seen Grapta comma disporting itself. We had 

 some remarkably fine weather in Quebec province early in the present year, and, 

 on the 5th of April, I captured at Magog a female specimen of Grapta J-aibwm. 

 I brought it alive to Quebec hoping to obtain eggs from it ; but, after keeping it 

 for some time, I came to the conclusion that it had not been fertilized. Mr. Caul- 

 field, mentions, in Can. Ent. Vol. IX., page 40, that he saw a pair of this species- 

 in coitu as late as April 26th. 



In parts of the country where the land lies open to the south for any con- 

 siderable distance, and where warm winds prevail, insect forms are found far from 

 their usual habitats. From Chateauguay near the valley of Lake Champlain and 

 the Hudson, Mr. Jack has recorded the capture of Papilio chresphontes and Eup- 

 toieta Claudia (Can. Ent. Vol. XIV, p. 219). And in the Niagara district, near the 

 extremity of the broad Mississippi valley, many southern insects have been taken. 



Hitherto we have noticed the effects of heat in hastening the development of 

 immature insects and in invigorating those that have reached perfection ; but we must 

 not forget to notice that heat intensified soon becomes fatal to insect life. 



The 22nd of March of the present year was unusually bright and warm, though 

 the snow still covered the ground. I was on a visit at Melbourne, Province of Quebec. 

 Tempted by the warmth, I took a chair and sat in the sunshine on the verandah of the 

 house at which I was staying. Looking up, I saw in the shadow of the roof a number 

 of water flies of the species Perla nivicola (Fitch). Presently one of these fluttered 

 down, and alit in the glare of the sunshine. In a moment or two it exhibited signs 

 of the utmost distress. It hurried hither and thither, whirled around as if seized with 

 vertigo, then curled up, and died. Soon another of the insects descended, and, after 

 vainly endeavouring to find shelter in a crevice, succumbed in the same way. I looked 

 round and found a number of the dead flies, all lying where the sun struck with greatest 

 power. The circumstance reminded me of the occasion of my first acquaintance with 

 Nemutits Ericksonii in its perfect state. In 1883 I had seen the larva? in great num- 

 bers in the border townships Bury, Lingwick, etc. In 1884, on an intensely hot summer's 

 day, I was crossing to Quebec in the Levis ferry-boat. The deck was like the floor of 

 an oven ; and scattered over it were numbers of the saw-flies. Migrating and weary, 

 they had been tempted to alight, ^and had been overpowered by the heat, and literally 

 roasted. 



We all know that, on bright "field-days," the morning before the sun has gained 

 its Btrength, and the afternoon, when it is on the decline, are the times for finding 

 diurnal insects on the wing. They seem to avoid exposure to the sun in its meridian 

 splendour. 



f have been testing the degree of heat that the potato beetle Doryphora decem-lineata 

 can bear ; and I find that water heated to 114° (96 degrees below boiling point) will 

 kill them. 



Boreal forms of insect life are met with in isolated spots in which the climatic 

 influences are exceptional. For instance, Chionobas semidea is found on the summit of 

 Mount Washington and nowhere else in a radius of many hundred miles. 



Mr. Scudder has given us valuable information concerning the effects of heat upon 

 Semidea. He tells us that the insect " cannot bear transportation so much as 3,000 feet 

 vertically to the base of the steeper slopes, at least if this transportation is effected in a 

 rapid manner." 



In a swamp, not far from Quebec, near the point where the great northern plateau 

 begins to recede from the river, C. Jutta may be met with. There are similar swamps 

 on the south side of the St. Lawrence ; but I have never heard that Jutta has been 

 found in them. 



