REPORT OF THE ENTOMOLOGIST AND BOTANIST 243 



SESSIONAL PAPER No. 16 



FOREST AND SHADE TEEES. 



No widespread or extensive injury to forest or shade trees was brouglit to my 

 notice during the past season, but there were many inquiries sent in with specimeng 

 for information concerning these insects. 



Tfnt Caterpillars of several species, which a few years ago were so enormously 

 abundant, but which everywhere suddenly decreased in 1900, seem to be again increas- 

 ing in certain districts, not only on forest trees, but also in orchards. There is som^ 

 confusion as to the species mentioned in reports; but western references are probably 

 to Malacosoma (CUsiocampa) calif ornica. Pack., and M. americana. Fab., northwestern 

 to M. disstricb, Hbn., and M. fragilis, Stretch, and eastern to the Apple Tree Tent 

 Caterpillar, M. americana, and the Forest Tent Caterpillar, M. disstria. 



Mr. J. E. Anderson says : — 



Victoria, B.C., Nov. 1. — The Tent Caterpillars again appeared in larger numbers 

 than usual this year. Iri some localities on the lower Fraser and in tliose places 

 where no steps were taken to check their ravages, fruit and ornamental trees were 

 utterly defoliated, and this was also the case with trees and bushes on the roadside.' 



When travelling in northern Alberta last summer, holding meetings with Mr. 

 T. N. Willing, the Territorial Weed Inspector and Entomologist, I found, on July 

 21, two destructive colonies of what I took to be the Forest Tent Caterpillar (M. 

 disstria). The first one was in a bush of many acres of Aspen Poplars, a few miles out 

 of St. Albert. The moths were in thousands and were just emerging from the 

 cocoons. Only a few dipterous and hymenopterous parasites were noticed at largo 

 or detected by their larvae in the cocoons. The second colony was close to the town 

 of St. Albert and was less extensive than the first one referred to, the chief injury 

 being done on the tops of yonng aspen trees. Earlier in the season Mr. Willing sent 

 me specimens of the larvae of Malacosoma fragilis, Stretch, which he had found abun- 

 dant on rose and other bushes at Medicine Hat. There are a few reports of injury 

 by Tent Caterpillars in orchards and wood lots in western Ontario; and I hear from 

 jSTova Scotia that Tent Caterpillars are evidently again increasing in numbers. 



The remedy for all these species, where practicable, is prompt spraying as soon 

 as the young caterpillars appear, with poisonous mixtures. 



Basswood Looper [Erannis (Hihernia) tiliaria, Harris]. — MJr. T. N. Willing 

 found caterpillars of this eastern moth very abundant on the flat north of the south 

 l^ranch of the Saskatchewan at Medicine Hat. They were stripping the Negundos. or 

 Ash -leaved Maples (also called Box-elders in the United States), and skeletonizing all 

 the leaves on some trees over an area of more than two acres. A moth was reared 

 from these caterpillars, v^'hich like the larvae, did not appear to differ in any way from 

 eastern specimens. 



The Negundo Twig-borer {Proleopieryx willingana,'KeaYi.). — For many years the 

 Ash-leaved Maples grown at Winnipeg, Brandon, Eegina and other points in the West 

 r.s street shade trees, have been injured every season by the caterpillars of a small 

 moth, which burrow in the bases of small twigs and branches, and hollowing these 

 out, cause them to swell and form elongated galls. These have occasionally been 

 reared, and some years ago moths were sent to a specialist who identified them as 

 Proieoieras cvscidanum, Eiley. Under this name the insect has been referred to until 

 tlio present season, when several specim^ens were reared by Mr. T. N. Willing, of 

 Ee^Ina, and were forwarded to Mr. W. D. Kearfott, a specialist in microlepidoptera. 

 ^ 16—164 



