66 Journal of Agricultural Research voi. x.no. 2 



ever, makes Fitch's name, since a homonym, unavailable. The writers 

 therefore propose the name " Prociphilus fitchW for this species. 



Another species of the same genus, P. corrugaians (Sirrine), occurs 

 upon pear foliage, causing the leaves to curl. All of these species, how- 

 ever, are quite different from the woolly pear aphis. 



Goethe, in 1884, (5) described a form occurring upon pear roots which 

 he considered to be a variety of the woolly apple aphis, Eriosoma lani- 

 gerum. He called it by the varietal name of pyri and stated that it 

 lives upon pear roots throughout the year. In the fall, according to 

 this author, winged forms are produced which fly to the underside of the 

 leaves in order to deposit the sexes. The female after fertilization lays 

 one egg upon the pear tree. No further observations were made into 

 the life history, so far as the forms from the egg are concerned. 



Mordwilko, in 1901 (7), stated that he had examined the form from 

 pear roots described as E. pyri by Goethe, and was convinced that it 

 could not be considered as a variety of E. lanigerum, but must be treated 

 as a good and distinct species. He therefore elevated the pyri of Goethe 

 to specific rank, and this name has been commonly used by European 

 workers for the root aphis which attacks pears. 



In 1 841 Hartig (6) described a species of aphid found producing sac- 

 like galls on elm trees under the name of E. lanuginosa. This species 

 has been redescribed and figured by several European students and its 

 work has become well known in the European countries of the continent, 

 as well as in the British Isles. It would seem from the statements of 

 Tullgren (9) that the species does not occur in the Scandinavian penin- 

 sula. In America Patch (8) has figured a gall from Connecticut which 

 was doubtfully referred to this species. No specimens were secured at 

 the time, and no positive record, therefore, was made. 



In Europe, where the life of E. lanuginosa on the elm {Ulmus spp.) 

 has been followed, its biology has been well understood and carefully 

 studied. Some of the earlier writers held incorrect views in regard to 

 the sexes and hibernation of the species, but later studies have cleared 

 up its entire life history. 



In 1914 Borner (3), acting upon the suggestion of Mordwilko, showed 

 that the E. pyri of Goethe is the alternate form of E. lanuginosa Hartig. 

 His experiments were made near Metz. Only a few galls were located, 

 and the insects from these were transferred to pear trees in pots. In 

 July two small colonies were present on the roots of the potted plants, 

 and the insects of these colonies were the offspring of the winged forms 

 of E. lanuginosa. It was thus definitely established that the European 

 pear-root aphis, Eriosoma pyri Goethe, is the alternate form of the elm 

 species Eriosoma lanuginosa (Hartig). 



The present writers (2) have described, under the name E. pyricola, 

 the American woolly pear aphis, which had before that time been thought 

 to be the woolly apple aphis. This was done because the form did not 



