APPENDIX I. whitman's MINNESOTA REPORT. 



[5] 



a good growth of wheat we have nothing to fear from locusts that come straggling 

 forth during the month of June. 



A considerable amount of eggs were destroyed during the fall and spring by various 

 insect enemies, birds, &c. It is difficult to estimate the amount of destruction that 

 goes on in this quiet, unseen way, but from the abundance of these enemies (particu- 

 larly insects) in certain localities, and from the palpable difference in such ])laces be- 

 tween tfte anticipated and the actual hatching, it is evident that these agencies have 

 all helped to make the result as favorable as it is. It has been a matter of common 

 report that in spots where eggs were abundant in the fall few or none could be found 

 in the spring ; and this was generally stated as a fact without attempting to assign any 

 cause for it. Even in 1876 replies to circulars, coming in during the fall, denoted that 

 a portion of the eggs deposited early in the season had already disappeared. During 

 the fall of 1876 reports were received from various quarters, especially the southwest- 

 ern counties, denoting the presence of the silky mite in great numbers, while various 

 larviie were discovered at work upon the eggs almost everywhere. The silky mite was 

 found to be still more numerous in the spring, sometimes so thick as to redden the 

 ground, and in localities where it had not been seen in the autumn. Of replies to the 

 inquiry of the Entomological Commission, "Proportion of the eggs that failed to hatch 

 and probable causes of the failure," nine out of thirteen (in Minnesota) express the opin- 

 ion that a large percentage (one-half or more) failed to hatch, and the cause generally 

 assigned is the silky mite. Testimony on this point can apply with exactness to only 

 such little areas as came under each man's particular notice, but the replies, taken with 

 similar reports, denote that considerable quantities of the eggs were destroyed by vari- 

 ous agencies before hatching. 



EFFECTS OF TEMPERATURE AND RAIN-FALL UPON THE EGGS. 



It is very doubtful whether excessive rain-fall during the autumn has any eflfect what- 

 ever upon the eggs, at least so long as they are left undisturbed. The following records 

 of temperature and rain-fall have been kindly furnished by Sergeant J. O. Barnes of 

 the signal office. Saint Paul : 





September. 



October. 



November. 



Totals. 



Eain-fall. 



Tempera- 

 ture. 



Eain-faU. 



Tempera- 

 ture. 



Eain-fall. 



Tempera- 

 ture. 



Eain-fall. 



1873 



Inches. 

 2.56 

 5.76 

 2.16 

 2.99 



54.1 

 f.0.9 

 57.2 

 56.8 



Inches. 

 2.57 

 3.21 

 1. 56 

 1. 27 



4L3 

 49.4 



42.8 

 43,2 



Inches. 

 0.79 

 1.90 

 0.84 

 0.93 



25.6 

 2.^.7 

 25.2 

 29.6 



Inches. 



5.92 



10.87 



4.56 



5.19 



1874. .. 



1875 



1876. . 





It will be seen that the total rain-fall of the autumn of 1874 is nearly equal to the 

 total of any two other years in the series, and it is certain that it was not followed by 

 any apparent diminution of the hatching in 1875. 



Again, there are many instances where continued immersion of the eggs in the spring 

 has no farther effect than to delay hatching until the moisture is removed. Statements 

 to this effect have been repeated a few times in various journals, and I add the follow- 

 ing extract from a letter, which seems to come from good authority : 



"Marshfield, Lincoln County, Minnesota, 



"September 10, 1876. 

 " On the 28th of August last, out on a hunting expedition, I crept down on the bank 

 of a lake among the reeds to get a shot at some ducks. In the reeds, among a thick 

 matting of tall wire-grass, I found millions of young hoppers just hatched. The eggs 

 were deposited last July (1875) and remained through the winter, and the water in 

 the lake, raised by spring rains, had stood over them until the first week in August 

 and then receded, and when I was there the warm sun was hatching them out. The 

 growth of grass indicated that last year, when the hoppers visited us, the water did 

 not reach that point. 



"C. H. GOODSELL, 



"County Audito?'." 



But the fact that moisture does delay hatching must he taken to prove that in a wet 

 spring the hatching in low grounds or such spots as retain moisture will be retarded 

 and uneven, exactly as has occurred during the past spring. 



The hope that the mild weather of February succeeded by the cold of March would 

 destroy the vitality of the eggs ended likewise in disappointment. The average tem- 



