2 



At Toronto the full grown insects — the producers — emerge from the galls, 

 the scales of which open to give them exit, about August Ist On emerging 

 they are slightly imperfect, but in one ' day ample wings are developed which 

 enable them to fly long distances, After distribution the female settles on a 

 spruce leaf and lays — under herself — about thirty-five eggs and then dies, 

 resting on the eggs. In about a week the young six-footed larvae are hatched. 

 They crawl about and find immature buds into which they burrow and of course 

 remain quiescent during the winter. But in the following spring their presence 

 in the bud causes it to develop into a " gall " instead of a normal twig. The lice 

 in the galls give birth to other living lice so that about thirty individuals are 

 found under each scale of the gall. The galls are usually irregularly spherical 

 and often more than a half inch in diameter. When growing they are of a 

 yellowish green color, but during the winter they assume a reddish brown tint, 

 which they retain until the end of May, when they usually fall from the tree. 

 This is the usual form of this gall but there is another form, not a gall, in which 

 the injury is done in the leaf axils. As these insects in the feeding stage are 

 within the gall, and the gall is perfectly water tight, so that no fluid can pene- 

 trate, poisoning is out of the question, and as in the migrating larval stage, they 

 do not eat, poison is equally useless. Of course in this larval stage soap emul- 

 sions might be of some use, if applied abundantly at the proper time. But 

 without any doubt the cheapest and best plan as yet tried in Ontario is to clip 

 off the galls as soon as they are noticed — say in June — and always hefore the first 

 of Anguiity while the producers are in the galls, and immediately burn them up. 

 When a tree is too much infested to be dealt with in this way it should be cut 

 down and burnt at once. Of course there is no use in doing this after the 

 producers are out of the galls. Several cases are known where this plan was 

 carried out with very satisfactory results, and it is respectfully recommended 

 that ail those having spruice trees in charge should carefully see to the clearing 

 of their trees and the extermination of this formidable insect pest. As some of 

 our nurseries are aflfected, buyers of evergreen nursery stock should be very 

 careful to see that the young trees are perfectly free from this insect pest. 



Description of Plate. 



Fig. 1. Gall infested twig as usually seen in the fall season before the death 

 of the part of the twig above the gall. 



Fig. 2. Infested twig of European spruce, two-thirds natural size, collected 

 April 16, 1898, from a badly infested tree growing in one of the Toronto 

 public pa'ks, showing the parts of the twigs above the gall dead, the leaves 

 having fallen off, the usual condition found in the spring season. 



Fig. 3. Mature, winged fertile form, from a microscope mount, enlarged 

 25 dia., collected September 1, 1897. In this final stage of development they 

 do not eat, but their ample wings enable them to fly long distances before 

 ovipositing, and hence the alarmingly rapid distribution. 



Fig. 4. Immature gall producer, from a microscope mount, enlarged 25 dia., 

 imm-^diately after issuing from under the scales of the gall, August 18, 1897. 



