ENTOMOLOGICAL SOCIETY OF ONTARIO. 25 



frigidum has the more j^raceful shape of the scrutator group, it is quite black, and bears 

 three rows of small bronzed or greenish punctures, which are, however, much less conspi- 

 cuous than those of calidutn. 



As an evidence of the rapid increase of frigidum during the recent infestation of 

 Canker Worms, it need only be mentioned that my first capture of this beetle was 

 on 2?rd May, 1883, on an island about three miles below the city, and that no other 

 specimen was taken by me until 28th June, 1891, During these eight years a careful 

 watch had been kept for this species, and many additions of less conspicuous beetles 

 had been made to my local lists, so that I was forced to the conclusion that it was 

 one of our rarest species. In 1892, however, as recorded in Ottawa Naturalist (Vol. 

 VI,, p, 150), I found several specimens in a locality where the Canker Worms were 

 very numerous upon ash trees, and also took two specimens in the city. This spring 

 the beetles were found to be quite abundant under stones, etc,, in the infested localities, 

 and later when the worms made their appearance on the foliage they were soon attacked 

 and greedily devoured by the beetles. Numerous examples of friqidnvi were seen 

 ascending the trunks of the basswoods and extending their investigation as high as 

 they could be watched. The worms seemed to be easily disturbed by the marauders, 

 and when a beetle ran out on a leaf they would drop down a few inches to elude it. 

 One of the less alert, or newly moulted worms, would, however, be captured, and it 

 took a very few seconds for the beetle to devour the juicy body of its prey and to 

 recommence the hunt. Enormous numbers of the worms must have been tl:us devoured 

 by this beneficial beetle. At the Experimental Farm, the beetle was also found in some 

 numbers on infested basswoods, showing that its range was becommg more extended. 



The Canker Worms were also attacked by parasitic hymenoptera, which, though less 

 conspicuous, may not have been less destructive than the beetles. One of these which I 

 have bred is apparently Apanteles paleacritce, a Braconid, described by Prof. Riley, 

 (Trans. St. Louis Acad. Science, Vol. IV., p. 313), from 3 females, 1 male, bred from the 

 larv;e of Paleacrita vernata, found at Villa Ridge, Southern Illinois, the flies appearing May 

 10th, and from 2 females bred from Canker Worm larv;o, probably of the same species, 

 received from Mr. J. Pettit, Canada West. This Apanteles differs from A. congregatus 

 and other common allied species, in that the host only supports a single larva, which, 

 however, seems to so exhaust its vitality that it does not reach maturity. Dr. Riley says 

 that : " The greenish white cocoons are spun singly on the under side of a leaf," but I 

 have often found that the parasitic grub, when satiated with the juice of the unfortunate 

 Canker Worm, emerges from its back and spins'its cocoon thereon ; the emaciated worm 

 bearing this upright burden, like a tower on his back, wanders feebly about until death 

 claims and relieves him. 



On the hickories I found numbers of the Canker Worms which had succumbed to a 

 difierent internal parasite, and had become mere contracted and stiffened shells, attached 

 to the leaves and stems on which they had died. Such a condition results with some 

 caterpillars from the attacks of species of the Ophionid genus Limneria, and perhaps may 

 have so resulted in this instance, but from a number of specimens collected I bred invari- 

 ably a species of Hemiteles, the members of which genus are aonsidered secondary or 

 hyper-parasites. I have not yet had time to thoroughly identify the pretty little species 

 bred from the Canker Worms, but it resembles H. sessilis, Prov., in having two well 

 defined bands on the wings, although evidently a distinct species, and closely related to 

 H. melitcecc, Ashm., if not identical with that species, which occurs in California. Another 

 ichneumon which was quite common about the infested hie ko lies was the handsome 

 Mesostenus thoraciciis, Cress, usually a rare insect, and I supposed from its unusual 

 abundance that it was parasitic on the Canker-worms. After closely watching their 

 movements, however, I ascertained that they were searching for the rough cases made by 

 a species of leaf-folding caterpillar, and that they perhaps confined their attention to 

 this species which was somewhat abundant. I collected some of the folded leaves and 

 bred from them both the parasite and the moth, the latter a pr-^tty little species, which 

 Mr. Moffat has kindly identified for me, and of which he says : " The name of the moth is 

 Ambesa Walsinghami, Rag, as identified for mo by Pruf. Kernald from a single specimen 

 taken at Hamilton several years ago, and I have never met with another. It belongs to 



