/ I ,J UNIVERSITY OF MINNESO ./ L ': BULLETIN NO. 43. DIVISION OF ENTOMOLOGY. --- --, Decer.n.ber, 1995. INSECTS IN.JURIOUS IN 1895. ST. ANTHONY PARIC, RAMSEY COUNTY, MINNESOTA. ·' H.\RinSON & S~IITH, PRINTERS, MINNEAPOLIS. UNIVERSITY OF MINNESOTA. BOARD OF REGENTS. The HON. JOHN S. PILLSBURY, MINNEAPOLIS, Regent for Li,fe The HON. GREENLEAF CLARK, M.A., ST. PAUL,­ 1900 The HON. CUSHMAN K. DAVIS, M. A., ST. PAUL, - 1900 The HON. WM. H. YALE, WINONA, 1896 The HON. JOEL P. HEATWOLE, NORTHFIELD, 1897 The HON. L. S. SWENSON, ALBERT LEA, 1897 The HON. ALPHONSO BARTO, ST. CLOUD, 1896 The HON. WM. M. LIGGETT, BENSON, 1897 The HON. S. M. OWEN, MINNEAPOLIS, 1901 The HON. STEPHEN MAHONEY, B. A., MINNEAPOLIS, 1901 The HON. DAVID M. CLOUGH, MINNEAPOLIS, Ex-Officio The Governor of the State. The HON. W. W. PENDERGAST, M. A., HUTCHINSON, - Ex-Officio The State Superintendent of Public Instruction. CYRUS NORTHROP, LL. D., MINNEAPOLIS, - - Ex-Ojficio The President of the University. TIIE AGIUCULTURAL COJ\Il\IITTEE. The HON. WILLIAM M. LIGGETT, Chairman. The HON. J. S. PILLSBURY. The RON. 8. M. OWEN. The HON. W. W. PENDERGAST. OFFICERS OF THE STA'.fION: WM. M. LIGGETT, - Chairman. WILLET M. HAYS, B. S. A., Vice Chairman and Agriculturist. SAMUEL B. GREEN, B. S., - Horticulturist. OTTO LUGGER, Ph.D., - Entomologist and Botanist. HARRY SNYDER, B. S., Chemist. T. L. H1ECKER, - Dairy Husbandry. M. H. REYNOLDS, M. D , V. M., - Veterinarian. TROS. SHAW, Animal Husbandry. T. A. HOVERSTAD, Assistant in Agriculture, at Crookston . .T. A. VYE. - Secretary. ANDREW BOSS, Farm Foreman. If@" The Bulletins of this Station are mailed free to all residents of the state who make application for them. INSECTS INJURIOUS IN 1895. OTTO LUGGER. CHINCH-BUGS. It is not necessary to give in detail the life-history of this insect, as it has already been given in Bulletin No. 37, pub­ lished by the Agricultural Experiment Station, which can still be had upon application. Yet as remedies depend very largely upon an intimate knowledge of this life-history, the essential points will be given. Fig. 1 illustrates the chinch-bug in its different stages: l FIG. 1. Different stages of the Chin~h-Bug. showing Eg;\'. Larva. Pupa ttnd Au ult. After Riley. The Ch inch-Bug, sometimes called the "Mormon Louse," has received numerous other names, as may be seen by the list of names by which it was mentioned in letters received in 189C>. It has from time to time caused immense losses; for instance, Illinois alone lost in 1871 ten millions of dollars, while the total loss for the six central states in that year amounted to thirty millions of dollars. The estimated loss in 1874 was sixty mil lion of dollars, and that of 1887 six hundred millions. In the same year Minnesota alone lost $6,790,821 in the counties 100 marked in the map, while the loss in others equally badly in­ fested was not given. The adult bugs winter in various positions, and can be found in large numbers hidden between the stools of timothy and wild grasses. Rubbish of all kinds, but chiefly that of hedges, wind· breaks and along the edges of woods, as well as corn­ fodder, logs and even loose bark and stones, offer shelter. In spring these bugs revive, and move to the nearest fields of small grains. Here they deposit their eggs, and careful inves· tigations by means of the microscope have shown that at least 225 eggs can be deposited by each female. These small eggs, of which thirty arranged lengthwise in a line cover about one inch, are not all deposited at the same time. but only from 15 to 20, which accounts for the fact that we may find adults. pupm and larvm of various sizes all belonging to the same brood; this also accounts for the fact that it is difficult to dem­ onstrate that the chinch-bugs have only two annual broods. Judging from 'the rapid increase in numbers farmers not un­ frequently claim that this insect has at least one hundred annual generations! The eggs of the first brood are deposited at the roots of such plants as wheat, rye, barley and grasses; plants of the above kinds, that grow nearest to the winter quarters of the insects, are first selected. The fact that grain-fields near edges of woods, or upon slopes, suffer most, is thus readily accounted for. But since the bugs fly at this period, fields suitable for them, i.. e. fields with a poor stand of plants, are selected and utilized. A good farmer, or one that is an agri­ culturist and not a pirate, a man that feeds his land as he ex­ pects to be fed by it in return, never suffers as much from chinch-bugs as an ignorant and slovenly one. When t.heplants infosted by chinch-bugs no longer afford liquid sap, the bugs of the first generation have to search for fresher material, and as they prefer to migrate on foot large armies are formed which moYe towards the nearest corn fields. They move most gener­ ally on foot, though many of the bugs already have wings, and in certain exceptional conditions will use them. After reaching the corn the eggs for the second generation are de­ posited, which mature in time, and produce the insects that search, on foot or wing, for sheltered places in which to winter. 101 YULNERAHLE POTNT8 IN THEIR HABITS. When we consider the life history sketched above, we find that a practical person will be very apt to discover some habits that could be utilized to kill large numbers of this pest. Con­ sidering the fact that these bugs find shelter under all sorts of rubbish, leaves, etc., it appears assuredly feasible to attack them there with good results. Clean farming, then, is not only godly, but an excellent remedy against that insect, and against many others. Let every farmer do his share of the work by not permitting any rubbish to accumulate upon his farm. In our usually dry autumns all rubbish will burn well. Such ma­ terial should be raked together in rows; this should be done before the bugs search for shelter, and as they surely will find such rows, they will not be slow to appropriate them for winter quarters. Later, rubbish a,nd bugs can be disposed of by fire. This work shuuld include the clearing and cleaning of the P-dges of the woods, of fences and fence-corners, of. hay-stacks and straw-stacks, and of wind-breaks: in fact, no rubbish should be permitted to remain upon the farm, for no rubbish means no shelter for the bugs. Besides this all the taller grass should be burned over; in fact let the fire be anywhere and everywhere excepting where it might be dangerous. The burning of dead foliage upon fields, meadows and prairies in former times ac­ counted, to a great extent, for the absence of many injurious insects at present only too common. We .know that chinch-bugs prefer certain plants and dislike others; they prefer millets. for instance, and almost invariably attack this plant when found in the infested region, while fl.ax repels them. It seems that barley is their second choice, then wheat, and later in the season corn. Winter rye frequently escapes harm, as it usually ripens too early, though a great deal depends upon the season, and rye may be destroyed by preference. Chinch· bugs do not like oats. This dues not mean. however, that oats will invariably escape their ravages. On the contrary, if more suitable food should be scarce, chinch­ bugs consider oats good enough for them. and act accordingly. By sowing millets very early, and having it above ground be­ fore the bugs leave their winter shelters. they will assuredly find and appreciate it, and will settle there in very large num­ bers. Of eourse the owner of such millet cannot expect to grow 102 both a crop of millet and of bugs, but will be forced to sacrifice the former to kill the latter. .T ust before the millet becomes too hard for the insect, it should be cut and left. upon the soil. The bugs remain upon it for some time before realizing the necessity of migrating, and this delay should be utilized to burn millet and bugs. Another point in the life-history of these bugs is their love for warmth and dryness, and consequently their selection of fields offering bo•h. Chinch-bugs prefer sandy soil or poorly cultivated soil simply because in such fields the plants are small and of irregular growth, thus permitting the sun to strike the soil directly, it not being shaded by the foliage. Fields well covered with plants, and consequently soils well shaded, are not attractive to these insects. A good farmer will not utilize such soils, but will enrich the sandy soil to such an extent as to produce a strong and uniform stand of plants; nor will he cultiyate poorly a good soil: neither will he be a robber of the soil by continuing to remove crops year after year without re­ turning something to the soil in form of manure to keep up its fertility. A good farmer will escape many losses by insects and other pests where a poor farmer would suffer. Good farm­ ing, and clean farming, should be the motto over every farmer's door. Poor farming means also a rank growth of weeds, and mainly of the different species of pigeon grasses, which in themselYes are a great attraction to chinch-bugs.