CATALOGUE OF BRITISH PLANT-GALLS 177 



Dlptera 



Homop- 

 tera 



Fungi 



Homop- 

 tera 



ULMACEAE 



Ulmus glabra Huds. {montana Stokes). 99. Wvch 

 Elm. 



Midrib of the leaf much swollen. The gall usually 

 appears as a rounded, hard, yellowish-green swelling on 

 the under surface, and a cylindrical projection on the 

 upper one, with the aperture at its apex ; but not infre- 

 quently the aperture is on the lower surface at right angles 

 to the swollen midrib. When young shooti are attacked, 

 the leaves are much distorted. Larva solitary, greenish- 

 yellow. M. E. Imago, April, II. (Plate XXIII.) 



Oligotrophus Lemeei Kieffer 300 



Swanton, Knowledge, June, 1910. Houard, No. 2061. 



Ovoid swelling on the midrib just above the petiole, 

 10 to 14 mm. high 7 to 10 mm. in diameter, covered with 

 serrated white hairs, yellowish. The leaf is more or less 

 deformed, and the midrib is incurved below the point of 

 attack. July and August. Aphis white or pale yellow. 



Pemphigus pallidus Halliday 301 



Syn. Pemphigus ulmi Halliday. 



Connold, Plant Galls, fig. 108. Buckton, ii., 127. 

 Houard, No. 2062.. 



Leaf margin swollen, puckered, and rolled loosely in- 

 wards ', very rarely both halves of the blade are attacked 

 and incurved. Greenish-yellow, tinted with red. June to 

 October. Aphis covered with cotton-like fibres. 



ScHizoNEURA ULMI Linn. 302 



Connold, Veg. Galls, pi. 107 ; Plant Galls, fig. 109. 

 Houard, No. 2067. 



Blisters or swollen patches on the leaves. The patches 

 are dark green at first, then blackish-brown, and often 

 cover a large area of the leaf. 



Taphrina ulmi Johans. 303 



Massee, Textbook of Plant Diseases, p. 92. 



Ulmua campestris Linn, {surculosa Stokes). 60. 

 Common Elm. 



On the upper surface of the leaf. An elongated or subglo- 

 bose glabrous gall, 10 to 12 mm. high ; pale green, purple 

 or reddish above, with an apical opening, which, together 

 with the neck of the gall, is surrounded with white hairs. 

 The leaf is discoloured and somewhat thickened around 

 the gall. Solitary or gregarious. June to September. 



