PROCEEDINGS, 1917. 75 



were at once made to make wholesale collection of these natural enemies and import 

 them into the New England States. In all thirty different species of parasites and pre- 

 dators have been introduced and seven or eight of these have become firmly established. 

 These latter have increased rapidly and are doing most effective work. The remaining 

 species have dropped out. These importations were continued until 1913. In the 

 meantime methods have been devised to artificially rear these parasites at the United 

 States Gipsy Moth Parasite Laboratory. The parasites thus reared were colonized in 

 different parts of the infested territory and in this way nature was assisted, as they were 

 spread much more rapidly over the area occupied by their hosts than would have been 

 the case if they were left to their own resources. Up to the present time over 18,000,000 

 parasites have been either imported or reared, liberated and colonized in the territory 

 infested by the brown tail moth?. 



Upon the appearance of the brown tail moth in New Brunswick and Nova Scotia 

 and on account of the close proximity of the gipsy moth to the Canadian boundary, 

 the Entomological Branch decided to profit by the example of the United States and in 

 addition to the artificial control methods, to import some of the parasites of these two 

 pests and endeavor to have them become established before the brown tail and gipsy 

 moths should appear in large numbers and infest the forest lands where artificial means 

 of control would be prohibited by their exorbitant cost. On account of the compara- 

 tively light infestation and widespread distribution of the brown tail moth in the in- 

 fested provinces and the total absence of the gipsy moth it was necessary to choose 

 parasites that were not only parasitic upon the brown tail and gipsy moths but also on 

 native insects, otherwise there would be great difficulty in getting them established. 

 The parasites finally chosen were the Braconid Apanteles lacteicolor, Vier., the Tachinid 

 Compsilura concinnata, Meig., and the beetle predator Calosoma sycophanta, L. 



The United States Bureau of Entomology was very willing to co-operate with this 

 plan. As all these parasites had become thoroughly established in New Kngland it was 

 "unnecessary for the Dominion Government to go to the additional expense of importing 

 them from Europe. Through the kindness of the Chief of the Bureau, Dr. L. O. How- 

 ard, part of the Parasite Laboratory at Melrose Highlands, Massachusetts, with all its 

 necessary equipment was set apart for the use of the Entomological Branch. The first 

 parasites were introduced into Canada in 1912 and this work was continued for five con- 

 secutive summers. The Entomological Branch stationed three men at the Melrose 

 Laboratory to carry on the collecting and rearing. 



Apanteles lacteicolor is a small hymenopterous parasite measuring 2.5 mm. in 

 length. The female Apanteles deposits an egg under the skin of the young brown tail 

 caterpillar in the fall. The egg hatches and the young parasite larva develops slowly 

 during the fall in the body of its host, remaining passive within the body of the hiberna- 

 ting caterpillar during the winter,. In the spring the caterpillars emerge from their 

 webs and start feeding upon the opening buds. The parasites likewise resume their ac- 

 tivity and feed upon the body of their host, devouring the less vital portions first but 

 later killing the caterpillar and emerging from its body. After emerging the parasite 

 spins a silken cocoon and emerges as an adult insect about ten days later. Apanteles 

 lacteicolor has two or three generations a year; after emerging from the brown tail cater- 

 pillars it may attack either the gipsy, Datana or Hyphantria caterpillars, the second or 

 third generation carrying them through until the young brown tails have hatched in 

 the fall. It is while the parasites are in the cocoon stage that they are forwarded to 

 Canada for colonization. During the winter months brown tail webs are collected from 

 points where Apanteles is known to be abundant. The webs are then placed in cold 

 storage to retard the emergence of the caterpillar until the late spring when the cherry 

 foliage is fully developed. They are then placed in trays. The webs are covered with 

 mosquito netting upon which cherry leaves are placed as food for the emerging cater- 

 pillars. When all the caterpillars have left the webs the latter are removed. The cater- 

 pillars are then fed three or four times daily until the parasites begin to emerge. The 



