212 • SMALL ANIMALS AND INSECTS. [Chap. IL 



much more numerous and destructive on the edges of fields than in the 

 center, and in some cases when the edges were comi:)letely -worthless, the 

 center bore comparatively a good crop. 



'• Fuuiigation with sulpluir, and burning weeds on tho windward side of 

 the field, when the grain is in blossom, have been recommended. Air-slacked 

 lime or wood-ashes, strewn over tho grain when in blossom, in the proportion 

 of one bushel of lime or ashes per acre, to be scattered over the field when 

 the plants are wet with dew or rain. Two or three applications have some- 

 times been found necessary. Plowing up tho ground, also, to destroy the 

 maggots ; and the dust-chaft', or refuse straw, if found to contain any of these 

 insects, shonld be immediately burned. In those parts of New England 

 where these insects have done the greatest injury, according to Dr. Harris, 

 the cultivation of fall-sown or winter grain has been given up, and this for 

 gome years to come will be the safest course." 



247. The Joint-Wormi — One of the greatest pests that Virginia farmers 

 have had to contend with in wheat-growing is the joint-worm. It has been 

 more destructive than the weevil, and in some cases as great a pest in that 

 State as the midge has in New York. 



The following is Glover's description of this insect : 



" Tlie joint-worm (Enrytoma hardei), which has committed such ravages 

 in the wheat-fields of Virginia, comes from a small, black, four-winged fly, 

 about an eighth of an inch in length. The female lays several eggs in the 

 outer sheath of the stalk above the joints. After they hatch, the worms 

 commence feeding within the slieath, and the constant irritation produced 

 by them forms a woody gall, or rather succession of galls, in the cavity of 

 each of which lies a small, footless maggot, about the seventh or eighth of 

 an inch in length, having a body with thirteen segments, and of a pale, 

 glossy, yellowish color. The number of worms in each cluster of galls varies 

 from four to ten, or even more. The substance of the stalk attached becomes 

 brittle, and either partially or entirely fills its central cavity, and frequently 

 distorts it into various irregular shapes. I have often observed young root- 

 lets putting out immediately below a joint so affected. The worms on the 

 stalks of wheat, when examined in February, were yet in the larva, but 

 early in March several had assumed the pupa state. They were about an 

 eighth of an inch in length, of a pale yellow color, which as the pupte were 

 near coming out, became afterward nearly black. These pupa? had the 

 rudiments of wings, legs, and antenna? as in the perfect fiy, but were motion- 

 less. Late in April and the beginning of May the flies made their appear- 

 ance through holes gnawed through the tougli, woody covering of the gall- 

 like excrescence in which they had passed the winter. This transformation, 

 however, took place in a warm room. These flies are about an eighth of an 

 inch in length, of a black color, the knees, joints, and feet being tinged 

 with yellow. The males, according to Dr. Harris, vary from the females by 

 being smaller, and in having no piercers. The joints of the antennse are 

 likewise longer, and surrounded with whorls of little hairs. The hind body 



