Chinch bug diseases

It has not been known until a comparatively recent date,that chinch bugs were subject to disease. In 1867 Dr. Shimer of Mt. Carroll, Ill. , presented a paper before the Academy of Natural Science of Philadelphia, in which he gave an account of a disease which so completely destroyed the chinch bugs in the vicinity of his home that it was impossible for him to find any specimens for his collection the following year. It was not then known and, unless specimens of the diseased bugs have been preserved, it probably never can be known with certainty what that disease was. Dr. Shimer only knew that it was an epidemic disease and that when the bugs died they were soon covered with a fungus or mould, which he thought to be the same as that which usually attacks dead animal matter. Sixteen years later Prof. Forbes, in his first report as State Entomologist of Illinois, gave a very full and interesting account of his careful studies of a bacterial disease, Micrococcus insectorum, which was very destructive to the bugs in Illinois in the summer of ’83. This was a true contagious disease and is conducted from bug to bug by microscopic germs as small-pox or yellow fever are conducted from man to man. Such diseases when occurring in the insect world are vastly more destructive than when occurring among human kind, as the bugs neither know the danger nor have any means of averting it. Bugs killed by this disease turn dark in color, become more or less shriveled in appearance, and when dead are not usually covered with mould

The Apple Curculio

A number of inquiries have been received at the station concerning the Apple Curculio, and I therefore give the following information concerning it. The Beetle varies much in size. The largest specimen in the station collection measures 3-16 of an inch. The beetles are often mistaken for the plum curculio, but they are easily distinguished from that species by the long, slender, somewhat curved beak and by the two prominent humps on the posterior portion of each wing-cover where the color is rust-red

Experiments with arsenites

Paris green was brought into prominence as an insecticide for the first time in this country in 1869 and London purple in 1877. Arsenious acid (white arsenic) was successfully used for the destruction of the Canker-worm as early as 1875 and is still frequently recommended for the destruction of insects. During these years the arsenites have arisen to the first rank as insect destroyers. They have been largely experimented with by entomologists and widely used by farmers and fruit-growers, and yet there is much difference of opinion as to the proportions in which each may be safely applied to different plants for the destruction of insects. In fact a serious obstacle in the way of a more free and successful use of the arsenites has been their liability to injure tender foliage; even when applied very dilute. In the experiments of the past two seasons, herein reported, I have given much attention to the finding of some method of applying these poisons so as to prevent injury to foliage without lessening their effectiveness in destroying insect life, and the success met with in this direction has been most gratifying. I also give the results of experiments to determine relative injuries to foliage from applications of the arsenites when freshly mixed and when allowed to stand a few days before being applied; to show the effect upon foliage by adding paste or soap to arsenical mixtures; to show the effects of sun, dew and rain upon foliage treated with arsenical mixtures; to show whether or not it is practical and safe, so far as injury to the plant is concerned, to mix the arsenites with insecticides that kill by external contact; and to show the effects of combining the arsenites with fungicides

Arsenic Experiments

The great value of arsenic in the forms of Paris green and London purple for the destruction of leaf-eating insects has long been recognized. As pure white arsenic in solution is occasionally recommended to take the place of the above named arsenites, and as I have been repeatedly urged to recommend its use on account of its greater strength and cheapness, the following experiments were mailed for the purpose of determining whether or not it can be safely used in this way for insecticidal purposes: One part of arsenic is soluble in 10 parts of boiling water and in 100 parts of cold water, the solution being as clear as the water used and remaining for an indefinite length of time without any sediment forming. In order to have solutions of known strength throughout, one ounce of arsenic was in each case dissolved in a gallon of boiling water for a standard solution, and from this solutions of desired strengths were mad

The Plum Curculio and the Plum Gouger. A summer\u27s study of their habits and remedies

These two arch enemies of the plum seem to vie with one another in their work of destruction in the Valley of the Mississippi. The Plum Curculio, Conotrachelus nenuphar, has received much attention from entomologists and fruit growers for a great many years in this country and there remains little to be added to what is already known of its habits and life history. But the best remedies for these two plum insects, and especially for the gouger, have not yet been fully determined. During the last two or three years the arsenites have been much talked about as curculio remedies and a few careful experiments, at least, have been made to determine their value for this purpose

The Potato Stalk-weevil

It seems best at this time to briefly call the attention of the farmers of the state to the Potato Stalk-weevil. Judging from all accounts that can be gathered, this has been one of our worst insect pests the past season. I believe that a half million of dollars would fall far short of making good the loss that it has occasioned the state this year from its injuries to the potato crop. The Potato Stalk-weevil at this place (and so far as I can learn, it is the first mention of the insect in the state) was first discovered by Mr. F. A. Sirrine, assistant botanist of the station, on 23 August, last, while he was engaged in examining potato roots for the presence of a fungus. Since that date I have personally examined a large number of potato patches in this vicinity and have found none that have escaped severe injuries from the ravages of this insect. In gardens where potatoes have been grown year after year, I have seldom found less than 75 per cent, of the stalks infested and from this to 93 per cent. In field patches at a distance from where potatoes were grown last year, I have found as few as 20 per cent, of the stalks infested, but in no case have I found the injuries less abundant than this

Food habits of the striped prairie-squirrel

Shall we kill the striped squirrels? Nearly everyone in Iowa who raises corn in field or garden will say, without hesitation, yes. I am not prepared to flatly contradict this reply but beg to call the attention of those who are indiscriminately taking the life of this little animal to the following short study of its food habits. I am fully aware that one serious charge is brought against this squirrel and that is that it destroys a large amount of corn early in the season by digging for the kernels. With this much of its food habits every Iowa farmer is familiar, but beyond this, little, to my knowledge, has ever been learned. In the Entomological Report of the Department of Agriculture for 1887, page 160, Prof. Osborn of the Iowa Agricultural College, speaks of having seen the squirrels eating the pupae of the sod web-worm, Crambus exsiccatus, and suggests that the squirrels may be very beneficial upon lawns and meadows by feeding upon the larvae (worms) also

Codling moth experiments

An excellent opportunity, of which I gladly took advantage was offered in my garden last summer for making tests and comparisons of certain remedies for the destruction of the larvae of the codling moth. The diagram given below shows the row of Duchess trees, Nos. i to 13 inclusive, that were used in the experiment with their surroundings. At A are two Fameuse trees, at B two crabs, at C a Red Astrican and a tree of an unknown summer variety, at D two Roman Stems, and at E four Duchess. The two Fameuse trees, the Red Astrican and one or two of the Duchess trees bore light crops ; all the other trees were heavily loaded with fruit