INSECT 'NO'J 355 



A New Spruce Tortrix, Argyroploce abietana Fernald. 



Lot 237. 



Spruce twigs with the needles dead and webbed together in a 

 silken mass were received from South Paris, May 20, 1908, with 

 the complaint that two small spruces were much injured in that 

 way. See Fig. 44. The inside of the leaves had been eaten 

 out by the larvae which entered by a hole made near the base of 

 the leaf. The webbed mass contained small felty cocoons with 

 greenish pupae inside. Upon request a considerable mass of the 

 webbed twigs was sent from the same place and over 40 of the 

 numerous moths which emerged were mounted. These were 

 not previously in the Station collection and were submitted to 

 Doctor C. H. Fernald who kindly named and described * them. 

 The females differ in no conspicuous marking from the males 

 described by Doctor Fernald. The wing expansion, however, 

 should read 11-13 mm. instead of 21-23 mm - as appearing by 

 mistake in the original description. The accompanying photo- 

 graphs Figures 45 and 46, will give a general idea of the color 

 pattern of this species. The fore wings might be briefly and 

 graphically described as being composed of alternate irregular 

 transverse bands of brown and bluish or silvery white. Accom- 

 panying the description of the male moth Doctor Fernald quotes 

 Miss Rose L. Davis concerning the larvae as follows : "The 

 larvae, when full grown, are about 7 mm. in length, cylindrical 

 in form, with the head of medium size, of a shining yellowish- 

 brown colour, and with a few fine hairs scattered over the sur- 

 face. The rest of the body is of a light greenish-brown colour, 

 semi-transparent. The thoracic and anal shields are of a pale 

 greenish colour, with the usual fine hairs on these and over the 

 surface of the body. When disturbed they quickly let them- 

 selves down by a silken thread." 



The cocoon is a firm gray structure about 7 mm. in length and 

 covered with pellets of frass. 



The moths began to emerge May 29, so that it would seem 

 probable that there are two broods a season. Since the cocoons 

 are made among the webbed twigs the most practical remedy 

 would seem to cut and burn such branches before the last of 

 May. This would be applicable to shade and ornamental 

 spruces and would prevent or greatly reduce the succeeding 

 generation. 



* The Canadian Entomologist, Oct. 1908, p. 349. 



