ON THE MILFOIL 
243 
Diptera 
5) 
> 1 
Homop- 
tera 
Nematoda 
Diptera 
Roots swollen near the stem. 
Trypeta guttularis Meigen 812 
Syn. Carpotricha guttularis Meigen. 
Connold, Plant Galls, p. 246. A. Muller, 1876, p. 18. 
Capitulum on the bud transformed in a hairy, subglobose, 
spongy gall, 5 to 20 mm. in diameter, white or tinted with 
red. Plurilocular. 
Rhopalomyia ptarmicae Vallot 813 
Trail, 1878. Houard, No. 5676, 5681. 814 
Flowers, leaves, and stems attacked. Galls about the 
size and shape of a hemp seed, green at first, becoming 
reddish, black at maturity ; opening at the summit star- 
like, with 4 or 5 rays. Interior lined with hairs, and con¬ 
taining a single yellow larva. The galls are either solitary 
or coalescent, in the latter state some imes forming a 
bunch as large as a filbert nut at the base of the stem. 
M. G. Imago, spring, II. (Plate XXXI.) 
Rhopalomyia millefolii H. Low 815 
Syn. Hormomyia millefolii H. Low. 816 
Connold, Plant Galls, fig. 327. Swan ton, Knowledge, 817 
June, 1910. Houard, No. 5673, 5680, 5685, 5691. 818 
A little depression on the lower surface of the leaf, with 
a raised area on the corresponding superior surface. 
Aphalara nervosa Forster 819 
Scott, i88i£, p. 18. Houard, No. 5689. 
Leaves and petioles swollen and distorted, bearing 
globular growths about the size of a hemp seed. Solitary 
or gregarious and coalescent, yellowish-green, becoming 
brown. Each gall contains numerous eel-worms. June tc 
October. (Plate XVI.) 
Tylenchus millefolii F. Low 820 
Connold, Veg. Galls, pis. 77, 97 (in the latter the galls 821 
are wrongly ascribed to Rhopalomyia millefolii) ; Plant 
Galls, fig. 328. Houard, No. 5684, 5688. 
Achillea Ptarmica Linn. 112. Sneezewort. 
Entire head of the plant transformed into a spongy, 
hairy, subglobose mass, 30 mm. in diameter, white or 
tinted rose colour, surrounded by numerous leaves. 
Cavities numerous, containing many larvae. M. G. 
Imago, spring, I. 
Rhopalomyia ptarmicae Vallot 822 
Syn. Hormomyiaptarmicae Vallot. 
Inchbald, i860, p. 164. Connold, Plant Galls, p. 246. 
Houard, No. 5706. 
