[10] REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



ner. While, by tbe last week of May, farmers were urging county and State author 

 ties to hurry on supplies of tar and sheet-iron, the locusts were encroaching at their 

 leisure upon the fields. A ditch around the fields at this time would not only have 

 kept out the young until other means of fighting were supplied, but would have ren- 

 dered other means unnecessary. Again, where the locusts were excessively numerous, 

 the extent of field which could be protected with a single tar-pan was small, and as 

 the locusts increased in size and activity, even this was daily lessened. When, in addi- 

 tion to this, the locusts were so extensively spread as to appear on all sides of a field 

 at once, and continued to appear for three or four weeks, the tar-pan soon became use- 

 less. Still, in a large number of cases, the locusts were so thinned out by this method 

 early in the season that what were left were afterward unable to make any serious 

 impression on the luxuriant growth of grain, or, if theji continued to be troublesome, 

 were caught with drag-nets or other catching-machines. The simplest of these and 

 the most efficient, in the latter part of June,when the locusts were large and the grain 

 several inches high, was merely a wooden scoop, similar to a wagon-body with one of 

 the sides removed. This, drawn over the grain, the open side foremost, at night, when 

 the locusts were roosting on the grain-stalks, collected the pupsB in immense numbers, 

 and, benumbed by the night air and dew, they rolled back into the trough and were 

 &oon piled together there in an inextricable mass, and could be disposed of at leisure. 

 One farmer in McLeod County estimated that he had caught 400 bushels, another 800. 



FIRST WINGED. 



A single experiment tried during the spring gave exactly sixty days from hatching 

 to full development of wings, on the 10th of June. As this was in confinement, possi- 

 bly the time was somewhat longer than would have been required under natural cir- 

 cumstances. Taking sixty days as the time required for the full development of 

 wings, locusts hatched on the 20th of April would become winged by the 19th of 

 June, and this corresponds almost exactly with the dates at which a few locusts have 

 begun to appear in the air every year since 1873. In fact, locusts, fully winged, have 

 been found in the field every year at a still earlier date. In 1876 they were reported 

 as early as May 26, but it may be doubted whether these were spretus. Last year 1 

 found winged spreius on the 8th of June, near Windom, and easily caught half a dozen 

 in a few minutes. But it may be stated as a general rule that in the latitude of Man- 

 kato the larger portion of the locusts hatch in the first ten days of May and migrate 

 in the first ten days ©f July. For the present year the earliest specimens of winged 

 spretiis were found in the fields about the 14th of June, and others were seen in the air 

 at the same date, possibly from elsewhere. From the 14th of June onward the winged 

 began to be noticed everywhere daily increasing in numbers, and had begun to move 

 about in large bodies by the 26th of June. By the 10th of July far the greater por- 

 tion had migrated, but there were still large numbers left in places, particularly in 

 those counties where the eggs had been laid late in the fall preceding. The same is 

 true of portions of Renville County. On the 6th of July, when the locusts had nearly 

 all flown from the neighborhood of Glencoe, they were still at work upon the crops 

 about Hutchinson, McLeod County. On passing through this region I found the locusts 

 more numerous as I went westward, and on the 8th of July the locusts were found to 

 remain still in Renville County, not only in excessive numbers, but at least two- 

 thirds of them in the pupa stage. It seems difficult to account for this in any other 

 way than by supposing that the eggs were laid later in the preceding fall. 



It is impossible to tell how much value to attach to the various reports of locusts 

 found dead in the fields. Early in the season such reports were generally traceable to 

 finding the shells of the locusts, discarded in molting. While some correspondents 

 state that next to none have been found dead, others report finding them in heaps, 

 and so numerous as to create a stench in the air. I have hunted carefully through 

 fields on every possible occasion to determine to what extent the locusts might be said 

 to be dying from natural causes, and while large numbers of dead have been found, 

 it was only an inconsiderable proportion of the whole. These were almost invariably 

 pupae, and I have seen them, at the thickest, lying at the rate of a dozen upon a square 

 yard of earth. But considering how easily such slight things escape the eye, and how 

 quickly they decay and disappear, the numbers noticed denote that a still greater num- 

 ber perished, and at least show that in respect to the efiect of climate or degeneration, 

 the past spring differs greatly from any that have preceded it. 



But in regard to the locust in Minnesota the year differs from the four past years in 

 nothing so much as in the character of the migrations. For four years past we Have 

 seen the locusts hatched here arise from their hatching-grounds and a part of them ap- 

 .parently. settle down to lay eggs in adjoining counties, while others from abroad have 

 added to their numbers later in the season, and the months of July and August have 

 been a period of constant coupling and laying. But the flying of the present year has 

 consisted almost entirely of migrations instead of mere change of base, and\warms 

 have repeatedly crossed the State, only rarely alighting in such masses as to be de- 

 structive, alighting less frequently as the season advanced, and leaving behind them 

 only trifling numbers of such as seeni to have dropped through weakness or from the 



