32 



The above statement of conditions is given in order to emphasize 

 the importance of a study of the conditions of insect outbreaks. 

 Were we better acquainted with accurate environments preventive 

 measures would invariably take the place of the more expensive reme- 

 dial ones. 



Capt. Charles L. Potter, Corps of Engineers, Memphis, Tenn., has 

 kindly furnished the following list of the breaks occuring in the Mis- 

 sissippi River (between Rolling Fork and Coahoma, the grasshopper 

 infested territory) since 1887: 



Name of crevasse. 



Distance 



by river 



from 



Cairo. 



Date. 



Remarks. 



OffUttS ; 



Miles. 

 444 

 530 

 435 

 438 

 288 

 432 

 354 

 503 

 492 

 380 

 434 

 300 

 548 



Mar. 18,1890 

 Mar. 26,1890 

 Mar. 28,1890 

 Mar. 28,1890 

 Apr. 3, 1890 

 Apr. 4, 1890 

 Mar. 11,1891 

 Apr. 3, 1891 

 Mar. 28,1897 

 Mar. 30,1897 

 Mar. 30,1897 

 Apr. 4, 1897 





Mound Landing 



Huntington 



Austim 



Catfish Point 



About 30 miles above Coahoma. 



Robertsonville 



Stella 



Deerfield 



Sledge 



















- There were no crevasses in the Mississippi levees from 1887 to 1890. 



A small crevasse occurred at Greenville in 1891 that was closed before the discharge was appre- 

 ciable. 



All the breaks except those at Flower Lake, Austim, and Shipland are located between Coahoma 

 and Rolling Fork. 



Grasshopper outbreaks occurred in 1891 and 1892, and again in 

 1898, 1899, and 1900. It is a significant fact that the rainfall of May 

 and June, 1893, and of the same months in 1900 had a decided effect 

 in suppressing the injurious numbers of grasshoppers, and conversely, 

 the dry summers immediately following the crevasses encouraged 

 greatly their development. 



The following table of rainfall for Greenville, Miss., the nearest 

 meteorological station, furnished by Mr. W. S. Belden, acting station 

 director, Vicksburg, Miss., supports the above conclusions. 



Rainfall at Greenville, Miss., 1888-1900. 



Year. 



Jan. 



Feb. 



Mar. 



Apr. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Annual. 



18 >S 



6.11 

 4.89 

 4. 98 

 3.79 

 5.59 

 4.63 

 7.37 

 6.32 

 3.29 

 4.31 

 8. 1'.' 

 . 30 



2.41 

 2.71 

 6.30 

 8.38 

 3.60 

 5. 27 

 3.19 

 5. 2 1 

 5. 2 1 

 4.05 

 2. 89 

 4.57 

 ... 11 



9.88 

 1.85 

 6.63 



4. 43 

 3.91 

 2.70 

 9.48 



7.'98" 

 11.48 



2.91 

 5.21 



5. 6 1 



1.65 

 2.60 

 11.01 

 2. 24 

 9.74 

 5.69 



1. is 

 1.71 



2. 18 

 1.96 

 3.83 

 2. L9 

 7.11 



4.54 

 4.03 

 4. 67 

 3.42 

 2.93 

 7.39 

 0.61 

 1.32 

 1.09 

 2. 19 

 3.15 

 1 i.7 



3.95 

 7.09 

 2.31 



2. 28 

 4.50 

 2. 23 



10.39 

 1.86 

 2.09 



2. 14 

 3.50 

 2.87 



"7.'23 _ 



1.S4 

 2. 2 1 

 7.51 

 87 



1 05 

 4.94 

 1.54 

 6.96 

 2.67 

 1.17 

 0.37 

 0.74 

 T. 

 6.12 

 1 is 



1.61 

 0.40 

 2.79 

 0.86 

 0.80 

 0.34 

 1.53 

 1.20 

 3.20 

 2.20 

 5. 85 

 1.15 

 5.03 



3.89 

 5.92 



1.4S 

 5.40 

 2.44 

 6.34 

 0.35 

 3. 78 

 4.73 

 2. 96 

 4.60 

 0.94 



3.89 

 1.05 

 3.94 

 3.40 

 6.54 

 1.87 

 4.25 

 3.58 

 0.17 

 8.37 

 1.51 

 4.23 



53. 29 



1889 



40. 95 



1890 



53.37 



1891 



3.02 



12.32 



51. 24 



1892 



1893 



i 894 



2. .54 

 6. 59 

 0. 30 



9.25 



2. 33 

 5.09 



57.80 

 48.69 

 37.81 



L895.. 



11.50 4.30 

 0. 71 ' 0. 85 

 1.05 3.85 

 2.51 L.57 

 1 :>l 2. 10 



45. 55 



1896 



L897 



1898 



1899. 



32. 32 

 44.66 

 50. 70 

 33. 92 



1900... 



1.94 



1.02 



9 "i fi. 11 



0.93 2.58 



1 42. 98 













1 For 10 months. 



