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The Most Important Shade Tree Insects of Quebec. 



The Elm Woolly Aphis, Eriosoma americana, is one of the few 

 important insect enemies of elms in Eastern Canada. These insects are 

 small plant lice which live upon the under side of the leaves, sucking the 

 juice and causing the edges of the leaves to curl over so that the insects 

 are largely protected thereby. The plant-lice secrete a considerable 

 amount of white wax threads and these colour the insects and the drops 

 of honey dew, so abundant in the cavities of the leaves where they reside. 



The pest usually becomes very numerous towards the middle or end 

 of June and often seriously disfigures or more or less seriously injures 

 the trees. 



Control Measures. — Kerosene emulsion or fish oil soap of ordinary 

 strength should be sprayed on the infested foliage as soon as the insects 

 appear on the leaves and before the leaves have curled. Less success 

 will be obtained after the leaves have become badly distorted so as to 

 cover the insects and protect them from the spray. 



The Elm Bark Louse, Gossyparia spuria Modeer. — The females of 

 this species are dark red, bordered with white wax and one-tenth of an 

 inch in length. They are usually arranged along cracks or fissures in 

 the bark of trunks and limbs, and lie irregularly on the twigs. They 

 suck the sap from the bark, often killing the infested branches and 

 finally the trees. The leaves below infested limbs become coated with 

 honey-dew and wax. The young appear in late June or early July and 

 are most readily controlled at that time. 



Control Measures. — The infested branches and trunks should be 

 sprayed thoroughly with kerosene emulsion or fish oil soap of medium 

 strength at the end of June, or beginning of July, while the minute young 

 lice are crawling upon the bark; the time for spraying should be when 

 most of the young are out of the eggs and must be determined by obser- 

 vation. A second application may be necessary. Lime-sulphur, winter 

 strength, applied before the buds start in the spring is also affective. 



The Forest Tent Caterpillar, Malacosoma disstria, is extremely 

 abundant and injurious periodically in this Province. The caterpillars 

 feed upon the foliage of various broad-leaf trees. The very severe out- 

 break of the last three years appears now to be dying out. 



