NEW BEITISH PLANT GALLS 27 



Brit. Plant Galls, pp. 74, 75). They occur very sparingly, 

 " generally on imported orchids, and mostly from the Brazils, on 

 the Brazihan Cattleyas." I am not aware of a previous British 

 record of this pest. 



II. — Galls neio to Britain, causers unknoivn. 



On Pteris aquilina. Tip of the segment of a frond slightly 

 rolled. Haslemere, August, 1915, E. W. Swanton. Howard 

 (Les Zoocecidies des Plantes d'E2tro2Je, III, p. 1262) records its 

 occurrence in Central Europe. 



Salix feagilis, S. babylonica, S. alba, and S. vitellina. 

 Catkins greatly deformed, and forming " witches' brooms " of 

 variable dimensions. Our present knowledge of these unsightly 

 galls and their distribution in England has been recently 

 summarised by Mr. Miller Christy in this Journal for April, 1915. 

 They are well known on the Continent, appearing on many 

 willows, and Howard {op. cit.) gives an excellent figure of a small 

 one. Mites have been observed in association with them by many 

 observers, but not in Britain, and Prof. Nalepa described them 

 under the name of Eriophyes triradiatus. Dr. H. Eoss {Die 

 Pflanze7ig alien [Cecidien) Mittel-zmd Nordeuropas, p. 255) associates 

 Phyllocoptes parvus with the "witches' brooms " on S. alba and 

 S. purpurea ; Phyllocoptes phytoptoides with those on S. baby- 

 lonica ; and Phyllocoptes phyllocoptoides with the galls on S. 

 purpurea. He also alludes to Aphis amenticola, an insect w4rich, 

 according to Howard, causes " Chlorantie des chatons avec phyllo- 

 manie et cladomanie " on various willows. If the "witches' 

 brooms " on willows result from the presence of mites, they are 

 probably caused by a single species, for it is generally observed that 

 each gall-causing mite gives rise to a very distinctive gall ; e.g., 

 there are three species of mites infesting alder leaves in this country, 

 but their galls are abundantly distinct. (See Brit. Plant Galls, 

 pp. 98, 99.) 



Ulmus glabra. Numerous circular spots on the leaf, 2 to 4 

 mm. diam., brown, with purplish margin, and having a central 

 opening on the lower surface. [Eriophyid ?] Between Allen- 

 dale and Allenhead, Northumberland, E. Bagnall, September, 

 1915. 



Crat^gus monogyna. — Pronounced swellings on the smaller 

 branches, at first globular, about J in. diam., showing numerous 

 larval cavities in the bark; at maturity 3 in. or more in length, 

 completely encircling the branch, which is markedly curved, its 

 bark brown and easily detachable. Sent by Mr. J. Eayner from 

 Southampton, August, 1915. Similar galls have been observed on 

 hawthorn in Germany, and are supposed to be caused by a 

 Cecidomyid. 



Epilobium angustifolium. Leaf margin abruptly folded 

 downwards and puckered at irregular intervals. The galling 



