The Spruce Budworm. 



By Arthur Gibson, Chief Assistant Entomologist, 

 Experimental Farm, Ottawa. 



In the annual report of the Division 

 of Entomology of the Dominion Experi- 

 mental Farms, covering the injurious 

 insects of the year 1909, it is purposed 

 to give a rather lengthy account of the 

 injury done in Canada to spruce and 

 balsam trees bj^ the Spruce Bud- worm, 

 Tortrix fumiferana, Clemens, during 

 the past summer. As this report will 

 not be published until the end of the 

 present fiscal year, it has been thought 

 advisable here to make a short state- 

 ment of the work of this insect, dealing 

 particularly with the ravages wrought 

 in the Upper Gatineau country of the 

 Province of Quebec. 



In July last, the Deputy Minister of 

 the Department of Agriculture was in- 

 formed by the Hon. Senator Edwards 

 that an insect of some kind was doing 

 much damage to spruce and balsam 

 trees in the above district, and as a con- 

 sequence I was instructed to proceed at 

 once to the infested locality to investi- 

 gate the outbreak. 



Early on the morning of July 29th, 

 therefore, I left Maniwaki, Que., in 

 coinpany with Mr. M. Boyle of the W. C. 

 Edwards Company, and drove to Bas- 

 katong about 40 miles due north. 

 Around Baskatong the injury to spruce 

 and balsam was very apparent, owing 

 to the conspicuous reddening of the tops 

 of the trees. Early the following morn- 

 ing we left Baskatong and spent the 

 whole day examining trees at different 

 points. 



As soon as the first tree was cut down 

 we saw at once that a lepidopterous 

 insect had been at work. Thousands of 

 the empty pupal cases of the moths 

 were present on the trees, and these, 

 with the partly eaten and discoloured 

 dead foliage, together with the excre- 

 ment from the caterpillars, gave the 

 conspicuous reddish appearance to the 

 tops of the trees. 



The injury for this year, of course, 

 had stopped before the time of our 

 visit. The caterpillars had evidently 

 become full-grown during the first and 

 second week of July. Moths which had 

 issued some days before the end of July 

 were present in large numbers on the 



trees, and from fairly good examples 

 collected, I saw that the species was 

 Tortnx fumiferana, Clemens, which is 

 knov^n popularly as the Spruce Bud- 

 worm. 



The caterpillars had fed chiefly at the 

 tops of the trees, although some injury 

 was done towards the ends of many of 

 the lower branches. The foliage for 

 about four or five feet from the tops of 

 the infested trees was almost wholly 

 destroyed, being either partly or com- 

 pletely eaten by the caterpillars. This, 

 with the exposed pupal cases above rt- 

 ferred to, gave the trees the conspicuous 

 reddish appearance, and caused the 

 rather widespread report among lum- 

 bermen that the trees were dying. In 

 looking over a valley on the opposite 

 hillside, the trees appeared as if fire had 

 swept through the region. Other than 

 loss of foliage and the consequent set- 

 back thus caused, the trees did not seem 

 to be seriously injured. The tops were 

 perfectly green under the bark. 



The outbreak of the Spruce Bud- 

 worm this year has been inost remark- 

 able and very widespread. Not only 

 has this insect done much damage all 

 through the Upper Gatineau country 

 and other adjacent districts, where there 

 are large tracts of spruce and balsam 

 trees, but even in British Columbia re- 

 ports have been received of much injury 

 by the Tortrix. Dr. C. Gordon Hewitt, 

 Dominion Entomologist, when in 

 British Columbia in October last, saw 

 the conspicuoiis work of the insect and 

 received reports from local entomolo- 

 gists concerning its ravages. 



The Spruce Bud-worm, when mature, 

 is nearly an inch in length, tapering 

 slightly from the middle to the end. 

 In colour it is dark brown and bears 

 conspicuous whitish-yellow piliferous 

 tubercles, and along the sides of the 

 body there is a yellowish stripe. The 

 eggs of the insect are scale-like and are 

 deposited in clusters overlapping each 

 other. The partly-grown caterpillars 

 pass the winter among the terminal 

 shoots of the trees, completing their 

 growth the following year. 



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