269. 

 PLANT GALL FORAY AT LEEDS. 



WM. FALCONER, F.E.S. 



The fitst sectional field day of the newly constituted Plant 

 Gall section of the Union was held at Leeds on May 28th last, 

 mainly — although incidental kinds were not neglected — for 

 the investigation of the spring forms of the Cynipid galls ol 

 the oak. Every member present was supplied with a list of 

 the latter, containing brief descriptions sufficient for the 

 identification of those likely to be met with and their location,, 

 and was able to engage with zest in a systematic search. In 

 the result a most interesting and successful day was spent ; 

 in the morning in Roundhay Park via the open-air baths, the 

 far side of the Waterloo Lake and the Gorge to the Mansion ; 

 in the afternoon a slightly increased party proceeded by way 

 of King Lane and King Wood to Adel Moor. Altogether 

 forty -three different forms were observed. Some fully ex- 

 pected to occur on the oak were not in evidence, in some 

 instances because the male catkins were not only very scarce, 

 but also too high up on the trees for examination. A local 

 species of ' greenfly ' was found on the fly honeysuckle, and 

 Mr. Dallman drew attention to another on the dog's mercury, 

 which is not yet on the British Gall List, and which he has 

 noted elsewhere in Yorkshire and Wales. The creeping 

 buttercup was noticed in one place to have one ' leaflet ' of 

 its trifoliolate leaf a little deformed and thickened in a plane 

 slightly varying from the normal and decidedly smaller 

 than the corresponding one on the other side. This deforma- 

 tion was seen to be due to Aphropliora spwnaria Linn. In 

 the Huddersfield district I have found on several occasions a 

 very distinct shortening of the floral axis and a resultant 

 massing of the flowers in the dock sorrel, also caused by the 

 same insect, which is accepted on the Continent as a true 

 gall-agent, and there is no reason why, with such unmistakable 

 examples before us, they should not be recognised as such in 

 this country. Two or three other noteworthy forms are 

 described and commented on in the list. One of them,. 

 Phyllocoptes epiphylhis Nal., would appear to be commoner 

 and more widely distributed than is usually supposed, but is 

 overlooked. 



The acarid and aphid material was taken home and sub- 

 jected to microscopical examination to verify the presence of 

 the gall mites in the former, and the stages of development 

 of the greenfly in the latter. 



The abbreviations employed are : — AC. = Acari ; DIP.= 

 Diptera ; HEM. = Hemiptera ; HOM. = Homoptera ; HYM.= 

 Hymenoptera ; FUN. = Fungi ; Q. sess. and Q. ped. = Q. sessili- 

 flora and peditncidata, the two common varieties of the oak, 



1921 Aug. 1 



