The Plant Galls collected by the Canadian Arctic 

 Expedition, 1913-18 



By E. PORTER FELT. 



The following report is based upon the material which was collected by 

 Mr. F. Johansen,. It is obviously fragmentary though nevertheless interesting 

 because the records are from a little explored region. The galls on Salix barclayi 

 appear to be new and the deformity produced by the Nematid is especially 

 interesting. A provisional identification was obtained through the courtesy of 

 Dr. L. O. Howard from Mr. S. A. Rowher of the United States National Museum. 

 The Eriophyid galls were submitted to Mr. H. E. Hodgkiss of the Agricultural 

 Experiment Station, Geneva, N.Y., and the few comments he saw fit to make 

 are appended to the characterizations of the deformities. It hardly appears 

 wise to bestow names upon these galls and thus add invalid or nearly invalid 

 names to a literature already overburdened with such appellations. 



Salix (willow). 



Nematid gall on Salix barclayi, labelled Teller, Alaska, July 26, 1913, 

 Frits Johansen. 



The gall is an irregular, oval, white, woolly mass projecting equally on each 

 surface of the leaf, divided by the midrib and with a major diameter of about 

 1 cm. The woolly fibers are 2 to 3 mm. long and within the compound mass 

 are two somewhat elongate ovate hollows, one on each side of the midrib. 



One gall examined contained a Nematid (possibly a species of Pteronidea) 

 and a parasite, a species of Eurytoma. The identification of the larva was made 

 by Mr. S. A. Rohwer of the United States National Museum, and that of the 

 parasite by Dr. L. O. Howard, Chief of the Bureau of Entomology. 



Cecidomyia species on Salix barclayi, labelled Teller, Alaska, July 26, 1913, 

 Frits Johansen. 



The gall is a somewhat irregular, rounded elevation, with a diameter of 

 about 4 mm., projecting almost equally from both surfaces of the leaf. It is 

 pale greenish-yellow, the surface with irregular rounded elevations and located 

 near the midrib. The interior is hollow, whitish, and the walls have a thickness 

 of approximately 0.5 mm. This is possibly the work of an Oligotrophus. 



Willow beak gall (Phytophaga rigidce O.S.) Specimens labelled Salix 

 species, Jasper Park, Alta., middle September, 1916. 



The galls are typical for this species except that they are smaller and 

 greatly wrinkled, a condition very suggestive of parasitism. The galls have a 

 length of about 1.5 cm., a diameter of 0.5 cm., and the surface is mostly dark 

 brown or blackened; the distal third of the gall is lighter, rather strongly 

 recurved and with the characteristic partly opened soft tip or beak. 



This insect ranges across the continent, if one may safely draw conclusions 

 from specimens of the galls. It is one of the more common willow inhabiting 

 forms, occasionally so abundant as to attack the tips of a considerable proportion 

 of the shoots in individual clumps. There is but one generation annually, the 

 insect wintering in the gall, and the midges appearing in early spring. An 

 extended bibliography is given in New York State Museum Bulletin 186, pages 

 213-214. 



