248 



BRITISH GALLS 



Hymeuop- 

 tera 



Acari 



Homop- 

 tera 



Hymenop- 

 tera 



Diptera 



Centaurea scabiosa Linn. 82. Great Knapweed. 



Large elongated swellings, or small rounded projections, 

 on the stems, striated longitudinally. Colour normal, 

 larval cells numerous. M. G. Imago, May, I. 



AULAX SCABIOSAE Giraud 858 



Syn. Aulax centaureae Thorns. 



Connold, Plant Galls, fig. 86. Houard, No. 5988. 



Irregular oviform swelling, about the size of a pea, on 

 the midrib at the extreme base of the leaf. Colour slightly 

 paler than that of the non-affected part. 



Aulax Fitchi Kieffer 859 



Fitch, 1877, p. 134. Connold, Plant Galls, p. 93 (with- 

 out name). Swanton, Knowledge, June, 1910. Houard, 

 No. 5991. 



Well-defined rounded pustules, 2 to 4 mm. in diameter, 

 on the radical leaves, projecting from both surfaces, chiefly 

 on thie inferior ; colour greenish, becoming dark violet or 

 black at maturity. Opening situated in the centre of a 

 depression on the upper surface. (Plate XXI. 4.) 



Eriophyes centaureae Nalepa 860 



Houard, No. 5989. 



Lapsana conmmnis Linn. 112. Nipplewort. 



Irregular bending and folding of the leaf. Aphis grass- 

 green, slightly reddish on the head ; cornicles long, pale 

 green. Aphides abundant in early June on the under sur- 

 face of the leaves. 



Macrosiphum alliariae Koch 861 



Syn. Siphonophora alliariae Koch. 



Buckton, i., 124. Houard, No. 6030. 



Crepis paludosa Moench. 62. Marsh Hawk's-beard. 

 Stem swollen. 



Cynips sp. 862 

 Fitch, 1879, P- 259. Houard, No. 6125. 



Hieracivim Filosella Linn. no. Mouse-ear Hawk- 

 weed. 



Gall ovoid, often 10 mm. in diameter, velvety, formed 

 by the rolling of a deformed leaf round the atrophied 

 shoot. Larvae gregarious, white, becoming red. M. G. 

 Cocoon white. 



Macrolabis pilosellae Binnie 863 



Syn. Cecidomyia pilosellae Binnie. 



Binnie, 1877, p. 179. Connold, Plant Galls, p. 245. 

 Houard, No. 6199. 



