CATALOGUE OF BRITISH PLANT-GALLS 143 
Diptera 
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Hymen- 
optera 
one within the other, thickened and more or less deformed, 
brown. The fusiform cavity contains numerous reddish 
larvae (20 to 30). The gall dries up after the departure 
of the larva or imago. M. G. or M. E. (Plate VIII. 4.) 
Perrisia terminalis H. Low 92 
Syn . Dasyjicura terminalis H. Low, Cecidomyia termin¬ 
alis H. Low. 
Connold, Plant Galls, p. 246. Houard, No. 582. 
Leaf margin tightly rolled towards the lower surface, 
tinted yellow or reddish, roll 3 mm. long. Numerous 
galls are usually present, and the margin is often rolled 
continuously for the greater part of its length on both 
edges of the leaf. M. G. I. 
Perrisia marginemtorquens Winn. 93 
Syn. Dasyneura marginemtorquens Bremi. 
MacDougall, Gall-Gnats on Osiers and Willows, Jour. 
Bd. Agric., Oct., 1905. Houard, No. 590. 
Hypertrophy of woody tissue on branches up to 4 inches 
in diameter, causing an irregular and slight swelling. These 
galls usually occur in large numbers on one branch, 
causing an elongated fusiform swelling ; the bark on its 
surface cracks and falls away. Larva greenish-yellow. 
M. G. Imago appearing the following May or June, 
leaving by a minute circular hole. 
Rhabdophaga saliciperda Dufour 94 
Syn. Cecidomyia saliciperda Dufour. 
R. Stewart MacDougall, Gall-Gnats on Osiers, Journ. 
Bd. Agric., Oct., 1905. Houard, No. 585. 
Fusiform or spherical plurilocular swelling up to 10 mm. 
in diameter on one-year twigs, caused by hypertrophy of 
the woody tissue. Surface pitted and of cork-like consis¬ 
tency. Petiole and midrib of the leaf also swollen; gall 
ovoid, hard, unilocular, yellowish-green, sometimes tinted 
with red. Larva whitish at first, then reddish. M. G., 
just below the outer skin. The pupa has a notch at the 
base of each antenna sheath. Imago appears late in May. 
Rhabdophaga salicis Schrank 95 
Syn. Cecidomyia salicis Schrank. 
Connold, Plant Galls, fig. 314. Houard, No. 587. 
Salix alba Linn. 92. White Willow. 
Bean-like swellings on the leaf blade. See No. 90. 
Cameron observes that “ on Salix alba the galls are 
usually pale green, rarely light red, and hairy below.” 
PONTANIA PROXIMA Lepel 96 
Syn. Nematus gallicola Ste. 
Cameron, ii., p. 203. Houard, No. 633. 
