GALLS CAUSED BY GALL-WASPS 
37 
reddish at first; Fig. 6 gives a magnified view of a growing 
one, and Fig. 5 a section of an adult. They arrive at 
maturity (Fig. 4, seven galls opposite to letter a) in 
September, become detached from the withering leaf, and 
fall to the ground. After falling, the gall loses its umbonate 
appearance and becomes round; the larva continues to 
grow in it, pupates in March, and the wasp, Neuroterns 
lenticulavis (Fig. 7), appears in April, a minute insect about 
2-5 or 3 mm. long. This gall was as abundant in 1904 as 
the alternate form. On three leaves from a sapling Oak 
at Haslemere I counted 286, 379, and 326 galls, an average 
of 330 for each leaf. 
Fig. 8, d , on Plate V., depicts the oval yellowish gall of 
Neuroterns albipes. It appears in May; the w r asp emerges 
and attacks the leaves in June, and the smooth spangle 
gall appears in July. This gall is cup-shaped (Plate V. 9,/; 
a magnified section is shown at Fig. 10). It matures in 
September, falls to the ground, and the wasp, Ncuroterus 
laeviusculus, appears the following March. 
Fig. 8, c , on the same plate, shows two blister galls caused 
by the presence of the larvae of Ncuroterus vesicator. These 
galls are pale green, and more or less rounded, projecting 
slightly from both surfaces of the leaf. On the superior 
surface there is a small raised point from which striae 
radiate to the margin (see magnified section, Fig. n). 
They appear in May, and the w’asps emerge in June, to 
prick the under surface of leaves and give rise to the 
beautiful little silk-button spangle galls (Plate V., Fig. 9, e ; 
Fig. 12 is a magnified section, and Fig. 13 an enlarged view 
of a gall), from which Neuvotcrus numismatis emerge in April, 
and attack the leaf buds, giving rise to blister galls. The 
silk-button gall was remarkably abundant in 1904. Three 
leaves bore 1,741 galls, in the proportion of 502, 558, and 
681. To appreciate fully the beauty of this gall it should 
be examined with a binocular microscope, using a 2-inch 
objective. 
Fig. 14 on Plate V. depicts two of the hairy Pea galls 
