EELWORM GALLS 
iog 
Tylenchus devastatrix attacks various Clovers, causing arrest 
of development. The internodes are shortened and thick¬ 
ened, and the leaves deformed, with involute margins. It 
also attacks the Buckwheat, causing thickening of the 
stems, shortening of the internodes, and enlargement of the 
leaves. It causes bulbous swellings at the base of the stem 
of the Sweet Vernal Grass, Shepherd’s Purse, and other 
wild plants. According to Connold, it is responsible for the 
deformed shoots and bulbous swellings on the lower part of 
Fig. 26—Stem Eelworms (Tylenchus devastatrix). (Greatly magnified.) 
Fig. 27—Anterior Portion of a Female, showing the Mouth- 
spear. (440/1.) 
Fig. 28—Embryo in Egg. (Greatly magnified.) 
From figures by Dr. J. Ritzema Bos. Reproduced from Miss Eleanor 
Ormerod’s "Manual of Injurious Insects,” by permission of 
Messrs. West, Newman and Co. 
the stem of the Wild Teasel. Houard attributes the galls 
on the Teasel to a Tylenchus , but leaves the species in doubt. 
I think I have seen it alluded to as Tylenchus dipsaci, but 
cannot find the reference. In T. devastatrix there is but one 
generation annually. Each female produces from 600 to 
1,000 ova. Miss Ormerod observes that “ the exceeding 
