Show f T vat at k irv I 1 f i t fc t ROOT WORMS undoubtedly MOST SERIOUS PEST small slender white grubs infest stalks of corn and cause young plants to wither by R L webster f pig 1 root worm enlarged fig 2 beetle the corn root worms are undoubted ay iy the most serious insect pests with which the iowa corn grower has arf contend the presence 0 root worms n a field Is usually indicated by a of the young plants the allure to produce well developed ais or a general retarding of the crowth without any visible cause A earch among the roots of such stalks nay bring to notice the tiny root borms the root worms themselves are mall slender white grubs about halt in inch long when they are full rown infested stalks of corn may be lulled out easily and will break oft at he place where the root worms are t work leaving the greater 0 the roots in the oll frequently stalks infested ay iy the root worm are blown to the round by the wind the root system laving been so cut off that stalks annot stand the strain bowman and have shown how a us cropping of corn on the same around will very soon increase In creise the number of root worms to an alarming green beetle about one fifth of an inch long in the fall these small green beetles are common objects on the silk of the corn and the flowers of the golden rad the spotted beetle of the southern corn root worm la frequently found along with the plain green beetle the beetles deposit their tiny eggs in the soil near the stalks of corn the next year eggs hatch out young root worms which begin to at tack the corn almost as soon as it Is out of the ground throughout the the summer these northern corn root worms are at work on the roots until the worms become full grown in the late summer when they become ma ture they transform to the pupa or resting stage in which stage they spend a short time finally the plain green beetle emerges from this pupa the beetles then deposit their eggs for another crop of root worms or the next year As far as it Is known there Is but one breed of this form in a season the beetle of the southern root worm Is green with 12 black spots on fig 3 southern corn root worm a beetle b egg c root worm d anal segment of larva e work of root worm at base of corn stalk fi pupa all enlarged except e which Is reduced extent and consequently decrease the yield preventive measures rotation of crops is the most effectual preventive of root worms the beetles of the root worms usually deposit their eggs in the old infested fields by changing the corn from such a field to another which was not in corn the preceding year these eggs are left behind there are two kinds of these worms the northern corn orm and the southern corn root worm since the habits of the two are very different in some essential a few further remarks concerning them are given below the two are eastly distinguished in the beetle stage when they are commonly found on the corn elite in the fall the northern form ol 01 the worm in its adult stage is a plain grass its back on this account of it may tw easily distinguished from the other form it Is also somewhat larger than j the plain green beetle measuring about a quarter of an inch long the black spots are in three rows across the back of the bettle each row with four spots usually these beetles are lound along with the plain green beetles on the silks of the corn but they are not so common the black spotted bettles are found not only in the fall but all through the season from early spring as well there seems to be at least two broods of them during the year the life history of the southern corn root worm la similar to that of the northern form except that it Is passed through in a much shorter time in the corn fields the eggs are deposited in tho ground near the stalks |