1913 



ENTOMOLOGICAL SOCIETY 



59 



The presence in, or in proximity to the Province of New Brunswick of these 

 four parasites naturally sugg"ests the question of whether or not the insect enemies of 

 the Brown-tail Moth now established in Massachusetts will be able to withstand 

 the colder winters of New Brunswick; the change involved is of course from the 

 transitional to the boreal life zone (these as recognized by Dr. C. Hart Merriam). 

 No definite statement can be made at the present time either one way or the other. 

 At the same time, considerable evidence bearing upon the subject has accumulated, 

 all of which supports the theory that the insect enemies introduced from Massa- 

 chusetts will flourish equally well in New Brunswick: the native Phorocera and 

 Trichogramma are known to be parasites of the Brown-tail Moth in both Massa- 

 chusetts and New Brunswick; the imported Pteromahis and Monodontomerus by 

 natural spread from Massachusetts have almost if not quite reached the borders 

 of New Brunswick; the host insect has shown itself adapted to the climate of 

 Massachusetts and New Brunswick, and an insect with a wide climatic range may 

 be reasonably expected to carry a sequence of parasites with the same range ; and 

 finally by making a study of the parasites of Hyplianiria in both places, the writer 

 has found that the sequence of parasites on that insect in each place is precisely 

 the same, and if the parasites are the same for Hyphantria in both places analogy 

 would argue them the same for Euproctis. 



In regard to the Brown-tailed Moth itself it was found that the life history 

 of the insect in New Brunswick differs at the present time in two points of con- 

 siderable economic interest from the life history in Massachusetts; these two 

 points are (1) in the selection of the host plants and (2) in the number of eggs 

 deposited by each female. 



In the matter of host plants the bringing together of the host records of all 

 the winter nests found in the Province during the winter destruction work of 

 1911-12 shows that pear, plum, and willow trees, which are favorite hosts in 

 Massachusetts, are scarcely attacked in New Brunswick. The following table serves 

 to illustrate the point: 



List of Trees and Sheubs ox which Nests are Found. 



Host. 



No. of B.T. Nests. 



% of total nests. 



Apple , 



Pear 



Plum 



Choke Cherry 



Pennsylvania Cherry 



Maple 



Bilberry 



Elm 



Oak 



Willow 



Poplar 



Thorn 



Beech 



89.55 

 04 

 51 



1.83 

 48 

 44 



3.26 

 61 

 08 

 04 

 04 



2.97 

 08 



100.00 approx. 



The column at the right hand side indicates the percentages of the total nests 

 that were found on the particular hosts. It will be seen that nearly 90 per cent, 

 of the total nests were found on apple, 3.26 per cent, on bilberry, 2.97 per cent. 



