mrbeliag the upper sheath, continuing sured and of the usual green color. The Her fly never affects the full-grown straws in this manner and the lesser wheat stem-maggot (Orcusis corttostoria) does so but rarely, so that the presence of these maggots in the straw can be easily detected shortly prior to harvest by their whitened color from the upper joint up ward. The larva: are within the stem and not outside and under the sheath, as with the Hes sian fly; they are larger and of a more glassy green color than those of the lesser wheat stem maggot, and it is only when still very young that the ordinary farmer need ever mistake than for any of the others mentioned in this article_ The liability of attack from this insect is not sufficiently great to warrant expensive preventive measures. It occasionally comes in vast numbers, but no way is yet known of fore telling these epidemics. The same precautions and methods as those taken against the Hes sian fly are recommended. Several other spe cies of Orrinis are known, among which the American frit-fly (0. rotor) may prove for midable hereafter, as it has already committed extensive depredations in Minnesota. The more careful and cleanly the method of farm nom the less are these and other insect pests to be dreaded.
The chinch-bug is another far too prevalent plague of grain-fields; it is, indeed, regarded as the most destructive insect in the country. It is a small blackish plant-bug (Burner eticofr tem:), with white wing-covers each marked with a dark line like a figure 6. Arising from her winter sleep in the old grass and rubbish of the fields and fence-corners, the female lays several hundred eggs on the stems and roots of the sprouting grasses and grains near her. The young hatch quickly, and in a crowd of reddish dots suck out the juices of the grow ing plants, causing them to wither and die. There is another brood in the fall. Severe winters and wet and cold springs reduce the numbers of this pest, and certain diseases are known which spread among the bags and de stroy them. Infected bugs have been sent from diseased districts to other regions and imparted to the bugs there with good effect. There teems to be no preventive, however, except great are in burning stubble and rubbish, keep ing the fieldi clean, and planting as late as pos sible.
Another group of highly injurious insects is found in the family Cholcidieke — a fam ily of gall-flies with one genus (Irosomo), whose species prey upon growing plants of this kind and are called straw-worms' or sjoint because their lame attack the nodes or •;centss of the grain-stem. The species of
special interest as affecting wheat is /. retitle for I. tritiri). This gall-fly is about an eighth of an inch long and lsiack, with a body shaped much like that of an ant and four dark wings. When is the spring, the young wheat plants are only starting to throw the stem upward, the females (at that time minute and wingless) push their ovipositors through the stem until the head of the embryo plant and leave an egg there. The larva soon hatching devours this vital part of the plant sod kill it, thoulth the stem may continue to VOW for sone time. By the middle of June the young have developed and cut their way out to appear as the adult summer form, which wander widely. These mature, winged females now deposit eggs within the stems of wheat just above the uppermost joint, where a hardy woody gall forms about the larva, within which it transforms into the pupa stage and stays on, inert, through the winter. The best preventive measure is an annual rotation of crops; next to that, the burning of the stubble, purposely left long, but this must be done not later than early September. Various other species of heroine attack other grams, espe cially barley and rye, and some others also In jure wheat Purples, ear-cockle or peppercorn is a dis ease of British wheat, produced by a minute nematoid worm called •wheat-eel' (Vibrio tritici), which are placed by their parents in the germ of the seed, and cause the formation of the purplish-black galls or 'cockles" which are a feature of the disease, and in which the worms are contained. When fatly grown they may attain a length of a quarter of an inch.
The Department of Agriculture has issued a large number of special illustrated publica tions upon the insects injurious to wheat and other grains, which should be consulted. Promi nent among than are Madam The Principal Enemies of Growing Wheat' (1901); Webster,