330 
N aturalists’ Field Day at Askham Bog. 
Biorrhiza pallida Oliv., common in both localities. Some * oak apples ” 
produce both sexes, others males only or females only. The two 
examples taken produced males only, together with some parasites. 
The males are winged ; the females not. The reason is obvious. 
The males have nothing to do beyond their natural function. 
The females must creep down deep into the ground to oviposit in 
a root ; wings would be an encumbrance. 
Neuroterus baccarum Linn., both localities, on leaves. 
Cynips kollari Htg., M. L. Thompson. 
Diptera. 
*Perrisia inclusa Frauen., old and new galls on Phragmites communis . 
No external indication beyond the perforation. 
Iteomyia capreae var. major Kieff, on *Salix pentandra. 
Rhabdophaga salicis Schrnk, on Salix caprea and cinerea. 
Macrodiplosis dryobia F. Low, on oak, Chandler’s Whin. 
Perrisia urticae Perr., on nettle. 
P. persicariae Linn., on Polygonum amphibium. 
*P. praticola Kieff on ragged robin. 
Oligotrophus bursarius Brmi. on ground ivy. 
Urophora solstitialis Linn, on black knapweed. No outward indication. 
Flies bred out 7th August. 
Rhopalomyia ptarmicae Vail, on sneezewort. 
Homoptera. 
*Psyllidl spec., leaf of birch blistered as in Rhopalomyia ribis ; insects 
plentiful on the under surface. 
Callipterus quercus Kalt.,. on oak, Chandler’s Whin. 
Aphis atriplicis Linu., on A triplex patula, in a tilled field bordering on 
the bog. 
A. viburni Scop., on guelder rose, both localities. 
Hemiptera. 
Aphrophora spumaria Linn., on Ranunculus acris, Potentilla comarum,. 
Rumex hydrolap athum, R. conglomeratus and Polygonum amphibium . 
Acari. 
Eriophyes rudis Can.,’ big bud,’ and E. lionotus Nal., on birch, the latter 
in Chandler’s Whin. 
E. atrichus Nal., on *Stellaria glauca With. 
*Eriophyes 1 spec:, on hawthorn leaf, Chandler’s Whin. On upper 
surface an unevenly rounded elevation tinted reddish brown ; 
a corresponding cavity below, 4 mm. in diameter, filled with an 
erineum of short, stout, irregularly bloated hairs, first pale,, 
passing through yellow brown to red. First noticed two years 
ago near Llangollen, N. Wales, and can find no reference to it in 
any gall book. 
Eelworm 
Tylenchus ? spec., on long rooted catsear, scape just below the capitulum 
swollen and distorted ; eelworms noted within the swelling. 
Fungus 
Triphragmium ulmariae Wint., parts of the leaf of meadow sweet 
swollen and distorted. 
The Annual Report of the Board of Regents of The Smithsonian 
Institute for 1920 is to hand, and is quite equal to its pre-war standard of 
excellence. It contains over 700 pages of valuable memoirs. 
The Proceedings of the Cambridge Antiquarian Society, No. 71, contains 
among much interesting matter, ‘ Killicks : a Study in the Evolution 
of Anchors,’ by R. Morton Nance ; ‘ Cambridgeshire “ Forests by 
Rev. H. P. Stokes. 
Naturalist 
