REPORT OF THE ENTOMOLOGIST AND BOTANIST 193 



SESSIONAL PAPER No. 16 



' The injury to the trees from these insects can be very great, especially in spring. 

 The growth stops and the trees become feeble and are thus susceptible to canker, which 

 often follows the damage done by the insect. The Larch Case-bearer is mostly found 

 on trees from 10 to 40 years old. 



' In nature the insects are devoured by many birds, and in autumn they are often 

 destroyed by protracted rains and by early frosts. 



' Trees badly infested by these insects should be cut down from the middle of June 

 till the end of August. This causes the leaves to dry up and the caterpillars die of 

 starvation. It would be better to burn the needles, but this is possible only in nurseries. 

 In the extensive forests of Canada it would be difficult to do anything effective to 

 destroy the insects.' 



The White-marked Tussock-moth (Hemerocampa leucostigma, S. & A.). — Of 

 recent years the shade trees in several of our Canadian cities have been very much 

 disfigured by the caterpillars of this well known native insect. Energetic measures 

 have been taken by the local newspapers and the civic authorities, particularly in 

 Toronto and Montreal, to reduce this quite unnecessary injury to the fine shade trees 

 in these beaiitiful cities. Public meetings have been called, and the advice of specialists 

 has been taken. There is nothing of any importance which is still unknown of the 

 habits of this insect, and all that is now necessary is the prosecution of a vigorous 

 campaign at once, so as to control as soon as possible, if not actually to wipe out, this 

 unwelcome guest which has done so much harm. The subject was treated of at some 

 length at a public lecture which I had the honour of delivering before Toronto Uni- 

 versity in February last, and again before the Toronto Horticultural Society in June. 

 The discussions were reported at length with further comments by the Toronto Globe 

 and other newspapers. A similar action was taken in the city of Montreal where a 

 conference was summoned by the Montreal Natural History Society, and a thorough 

 discussion of the subject took place. The Montreal Star, La Pres^e, and other news- 

 papers, published several articles in their daily editions, and at request I prepared a 

 full arti<'-^ for the ^YeeJcly Star and Family Herald. The course of action recom- 

 mended by me at all of the above meetings was to destroy the caterpillars by spraying 

 the trees while the caterpillars were young, with arsenites or other active poisons, and 

 the collection of the conspicuous egg masses during winter. Prof. D. P. Penhallow, 

 of McGill University, has taken an active and useful part in distributing information 

 on the subject, and in drawing the attention of the public of Montreal to this important 

 matter, and his efforts have been ably supplemented by Mr. H. H. Lyman, who has 

 materially assisted with expert advice as to the correct natural history of the insect. 

 It' is to be hoped now that public attention has been drawn to this matter, vigorous 

 measures will be adopted, and that private citizens will second the efforts of the muni- 

 cipal authorities by attending to their own trees and gardens, which cannot be well 

 reached by officials. In this way this insect may be very much controlled. Its pos- 

 sibilities for injury are only too well known by what it has done in New York, 

 Kochester, Cleveland and other cities in the United States. 



The Vancouver Island Oak-looper (Therina somniaria, Hulst). — The beautiful 

 oak trees which form such an attractive feature of Victoria, Vancouver Island, have 

 again this year suffered severely from the attaclis of the caterpillars' of this geometrid 

 moth. It was hoix;d from the large numbers of parasites which were reared from the 

 pupie last autumn, that the injury during 1905 would have been less than in the pre- 

 ceding season. These hopes, however, were doomed to disappointment, for the caterpil- 

 lars occurred last spring in countless myriads and stripped every vestige of foliage 

 from most of the oaks around the city and for several miles out into the country. Mr. 

 J. R. Anderson wrote under date June 23': — 



' Therina somniaria is already at its deadly work worse than ever. The oaks in 

 some places are already stripped of their leaves, and other plants are being attacked 



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