. The American entomologist. Entomology. THE. VOL. 1. ST. LOUIS, MO., APRIL, 1869. NO. 8. CIjc ^merkatt ^ninmokgbt. PUBLISHED MONTHLY BY F. 'Sr &; CO. 104 OLIVE STREET. ST. LOTTIS. TERMS One dollar per annum in advance. EDITORS : BENJ. D. WALSH Eock Island, lU. CHAS. V. UILEY, Clark Ave St. Louis, Mo. THE JOINT-WORM. (Isosoma /lordri, Harris.) Its Oiierations upon small Grain. In certain years and in particular States the crops of wheat, of barley, or of rye are ob- served to be greatly injiirecl by a minute mag- got, popularly known as the "; This maggo
. The American entomologist. Entomology. THE. VOL. 1. ST. LOUIS, MO., APRIL, 1869. NO. 8. CIjc ^merkatt ^ninmokgbt. PUBLISHED MONTHLY BY F. 'Sr &; CO. 104 OLIVE STREET. ST. LOTTIS. TERMS One dollar per annum in advance. EDITORS : BENJ. D. WALSH Eock Island, lU. CHAS. V. UILEY, Clark Ave St. Louis, Mo. THE JOINT-WORM. (Isosoma /lordri, Harris.) Its Oiierations upon small Grain. In certain years and in particular States the crops of wheat, of barley, or of rye are ob- served to be greatly injiirecl by a minute mag- got, popularly known as the "; This maggot is but little more than one-eighth of an inch long, and of a pale yellow color with the exception of the jaws, which are dark brown. It inhabits a litlle cell, which is situa- ted in the internal substance of the stem of the affected plant, usually a short distance above the first or second knot from the root, the outer surface of the stem being elevated in a corres- ponding elongate blister-like swelling; and when, as is generally the case, from three to ten of these cells lie close together in the same spot, the whole forms a woody enlargement "honey-combed by cells, and is in reality a many- celled or "polythalamous" gall, analogous in its nature and structure to those which we have described in a preceding article. (No. G of the Amek. Entom.) In Figure 113, a, will be seen a .sketch of one of these galls, the little pin- holes being the orifices through which the flies produced from the joint-worms have escaped. At first sight, these knotty swellings of the stem are apt to elude observation, because, being almost always situated just above the joint or knot on that stem—whence comes the popular name "Joint-worms'"—they are en- wrapped and hidden by the sheath of the blade; but on stripping off the sheath, as is supposed [Fig. ll:i ]. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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