128 The Galls of Essex; a Contribution to a
Artemisia vulgaris, L. Leaf. Small, red or red and
green galls on the upper surface of the lower leaves. The
larvae pupate within the galls. Cecidomyia foliorum, H.
Loew.
Carduus arvensis, Curt. Stem.
The stem is considerably swollen
into a hard, woody, ovate, or
globular gall, but the stem con-
tinues to grow and leaves are pro-
duced above the gall. The gall is
most commonly found in cultivated
fields. The galls are multilocular,
containing from two to eight fat,
white larvae with brown heads,
which pupate within the gall. Uro-
phora Cardui, Linne. (Fig. 12
Centaurea nigra, L. Flower-

head. The ovary is transformed

Fig. 12. Urophora Cardui.
into hard, woody, irregularly oval,
confluent galls to the number of two or three in one flower-
head. The appearance of the head is not changed, and the
galls are only tactilely noticeable. The white larvae change
to black pupa? within the gall. Urophora solstitialis, Linne'.
Hieracium umbellatum, L. Stem. Hairy, green, rounded
swellings of the stem, generally of about the size of a walnut.
The galls are multilocular, and the larvae pupate therein.
Aulax Hieracii, Bouche (=A. Sabaudi, Hartig).
Campanulaceae.
Campanula rotundifolia, L. Seed capsules. The galled
capsules are much swollen, and become much thickened and
fleshy ; they are not, however, particularly noticeable. The
black larva? pupate within the galls, often two in one capsule.
Gymnetron Campanulae, Linne.
Jasminaceae.
Fraxinus excelsior, L. Leaflets. The midrib of the
leaflets is much swollen, enclosing an oval purse-like chamber