pleted. All determinations have been made in duplicate and some of them have been repeated from four to eight times in order to leave no room to doubt their accuracy. Over three hundred single determinations have been made in this work alone and each determination has taken much time.

Qualitative examinations of four samples of artesian water have been made for the committee on irrigation.

Several samples of marl have been analyzed and as is the case in all laboratories many miscellaneous substances have been sent in to have some one or more substances determined.

Many comparative determinations in mechanical soil analysis have been made, and three full samples, top soil mixed soil and subsoil, have been analyzed in duplicate.

The total number of samples having a complete analysis, and this includes water, beets, grasses, peats, etc., amounts to one hundred and twelve.

Work on grasses is still in progress.

DEPARTMENT OF ENTOMOLOGY.

I. H. ORCUTT. ENTOMOLOGIST.

The work of the Department for the last year has been of two kinds. First, an attempt to keep in check the injurious insects of the farm, garden, and tree plantations. Second, such experiments and original investigations as could be made, The progress of events showed early in the season of 1889 that cut-worms were among our worst enemies and quite generally distributed throughout the State. They have, therefore, received as much attention as circumstances would allow. Notes, more or less extended, were made on various other pests in their season but this group has been selected as our chief subject of study.

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To speak of the cut-worm in a general way may be intelligible enough to most people, but still it should be remembered that there are very many species. While there is a general similarity of habits among the more common species, it may be found that the differences which exist are sufficient to require widely different methods in the extermination of the worms. It seems strange that these insects, which are among the worst pests all over the country,

Probably the

should not have been more fully studied. difficulty of finding the eggs is the chief reason. Our own efforts last year were quite unavailing, though we confined large numbers of the moths in a room with a variety of growing plants. The experience of the season was very useful, however, and will enable us to renew the effort with better prospects of success.

The plants most injured at the Station were garden vegetables and young trees. Seedling boxelders were cut off and destroyed. A plantation of trees from one to three feet high was badly eaten, the worms climbing to the tops of the tallest trees.

starve.

This was on a plat kept absolutely free from all other growth, so the worms had no alternative but to climb or The trees were of several kinds and they selected elm, cherry, boxelder, maple, birch, and ash, but avoided the poplars, pines, and larches. It was not at all uncommon to find twenty worms about the base of one little tree of any of the kinds injured, and in one or two cases over forty were dug out. One evening an examination was made with a lantern and about half a dozen worms were found in each tree, eleven being the highest number observed. In the raspberry patch, where the cultivation was equally good, a single bush was found that night to contain thirty-eight worms.

The chief questions for further investigation may be stated as follows:

I. Is there anything in the state of cultivation of a field, or the kind of plants growing on it, that determines whether eggs shall be laid there? If there is any particular kind of plant upon or about which the moth prefers to lay her eggs, the knowledge of the fact is of the very highest practical importance. The time for close observation and study is not in the spring when the worms are injurious, but in late summer when the laying of eggs for the next brood is in progress. It may be that investigation will show that the common cut-worm moths lay their eggs indiscriminately upon whatever plant is convenient Still

the possibility of a valuable discovery in this line should not be neglected.

2. Will a crop, such as millet, which the worms do not like, and which chokes out all other growth, leave the ground free from worms?

3. Is there any time of the year when plowing will destroy the worms, or lessen their numbers?

4.

Can parasites be introduced which will keep the worms in check?

In order to supplement our own work with the experience of the farmers of the State, we issued last fall a circular of inquiry respecting cut-worms. It is much to be regretted that the large number sent out did not bring us more replies. Many counties were not heard from at all, and some others were represented by only a single answer. Evidently many of the recipients of the Station Bulletins do not appreciate fully the value of hearty and unanimous co-operation.

The amount of damage done was the subject of the first inquiry. The replies referred chiefly to corn. No estimate can be made regarding the damage done to other crops, as they were referred to but briefly or not at all in the reports.

From the reports the average loss of corn appears to be twenty-one and one-half per cent. of the crop. The worst section reported was Spink county, with Brown and Beadle next. From Aurora, Sanborn and Hand counties reports of heavy losses were also received. From the estimates given, it appears that the total loss of corn for 1889 did not fall far short of 60,000 acres, worth at the time probably $250,000.00. From the reports received to date it is estimated that the damage to crops in South Dakota by cut-worms will nearly or quite reach $400,000.00 for the summer of 1890. In many localities the barley, oats, and wheat were destroyed as well as the corn.

Out of about sixty correspondents only one had known the worms to follow a thrifty crop of millet. This is an important point. The crop preceeding the cut-worm attack was usually oats or wheat, the number of times that oats

were mentioned strongly indicates that they are more liable than wheat to be followed by the worms, The replies

seem to indicate that corn after millet would stand the best chance of being unmolested, while on oat ground it would have the poorest chance.

Much work has been done in the line of introducing parasites to destroy the "boxelder worms" (larvae of the Cecropia emperor moth). The Department has not been as useful to the farmer in this matter as it would have been if more had sent in cocoons as requested so that it could have been determined where parasites do, or do not, already exist. More work will be done in this direction. In this locality the parasites, with a little help, have almost entirely exterminated this very destructive insect.

The introduction of parasites seems to be the solution of at least a part of the great insect problem.

The correspondence for the past year has been large, requiring much time, but not two per cent. of what it ought to have been. The Entomologist wishes to hear from every farmer in South Dakota who can give facts and personal observations.