122 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



Entomologist for the control of some particular pest or pests. The 

 inspector is paid his per diem and expenses out of the County treasury 

 and is at all times under the control of the State Entomologist and 

 County Horticultural Inspector. 



No pest districts have been formed, as yet, probably for two reasons. 

 In the first place, the law did not go into effect until August of the 

 present year and, in the second place, the grasshoppers in northern 

 Colorado have not been at all abundant during the past summer and 

 fall. This seems very strange as the eggs were deposited in unusual 

 numbers during the fall of 1910 and seemed to go through the winter 

 in excellent condition so that the young hoppers appeared in extraordi- 

 nary numbers during the month of May. From the time of hatching 

 until the time for egg laying, the latter part of August and during 

 September and October, their numbers rapidly grew less, so that com- 

 paratively few of the egg pockets were deposited the past fall. 



The great diminution in numbers of grasshoppers during the sum- 

 mer is hard to account for. I have noticed in former years a similar 

 condition, namely, that when the grasshoppers become unusually 

 abundant we are almost certain to have a great reduction in numbers 

 in the immediate future. Apparently, this reduction has been due 

 chiefly to outbreaks of the grasshopper fungus, Empusa grylli, which, 

 however, has not been very common the past summer, although it is 

 accountable for the destruction of a great number of grasshoppers in 

 northern Colorado during the present year. Farmers have been of 

 the opinion that the red mites {Tromhidmm sp.)' have been largely 

 responsible for the destruction of grasshoppers; but from my observa- 

 tions in the field I have never been able to convince myself that these 

 mites were of any considerable importance either in the destruction 

 of the adult grasshoppers or their eggs, and these mites have not been 

 more abundant upon the grasshoppers during the past summer than 

 usual. The blister beetles (Macrohasis unicolor and other species) 

 have been common but not unusually abundant throughout the in- 

 fested sections. Dipterous parasites (?) Sarcophagidse, have been 

 reared in considerable numbers from the dead hoppers but we are 

 not convinced that these flies attack the living grasshoppers. So I 

 shall have to confess my inability to assign any satisfactory explana- 

 tion for the great reduction in numbers of our grasshoppers in 1911. 



The methods of control that we have been recommending and that 

 have been most successful are, first, a thorough harrowing of alfalfa 

 fields, ditch banks and roadsides, where the eggs are mostly deposited, 

 at some time during late fall, winter or early spring. I recommend 

 that the harrowing be repeated several times for the purpose of thor- 

 oughly breaking up the egg pockets and bringing the eggs to the sur- 



