THE SLENDER SEED-CORN GROUND-BEETLE. 



27 



WEATHER CONDITIONS. 



The facts concerning the temperature and moisture of the periods 

 over which the experiments, described above, extended were obtained 

 from Mr. Walter Vossler, the local observer at Richmond, Ind. The 

 conditions prevailing at Richmond were very nearly the same as 

 those at Mr. Baker's farm, which is only 8 miles away. 



The following table gives the maximum, minimum, and mean tem- 

 peratures and the rainfall in inches for the months of April, May, and 

 June in 1908 and 1909: 



Table IV. — Temperature and rainfall conditions at Richmond, Ind., April, May, and 



June, 1908 and 1909. 



Month. 



Maxi- 

 mum. 



Mini- 

 mum. 



Mean. 



Rain- 

 fall. 



Month. 



Maxi- 

 mum. 



Mini- 

 mum. 



Mean. 



Rain- 

 fall. 



1908. 



80 

 92 

 93 



24 

 29 

 39 



52 

 60 

 66 



Inches. 

 3.76 

 4.97 

 2.69 



1909. 

 April 



82 

 83 

 88 



20 

 32 



47 



51 

 57 

 67 



Inches. 

 4.68 





May 



5.37 







5.74 









NATURAL ENEMIES. 



A small mite (Canestrinia sp.) has been found in great numbers in 

 the abdomen of the adult beetles. As cited on page 19, this mite 

 apparently destroys the beetles, though nothing definite has yet been 

 learned as to the extent of the destruction from this source. 



PREVENTIVE MEASURES. 



Since the beetles confine themselves to low, swampy land, it would 

 appear at first glance that the remedy is very simple — cease planting 

 such land to corn. However, to a man whose farm consists chiefly 

 of such land, this would seem very poor advice. In the vicinity of 

 Richmond, Ind., corn planted about the middle of June is but little 

 disturbed. From the foregoing it would appear that the greater part 

 of the damage may be avoided by late plantings. This would seem 

 to offer some relief. The class of soil mentioned above usually re- 

 mains wet and cold until quite late in the spring, but even in case the 

 spring should be a dry one, the extra time could be very well em- 

 ployed in preparing a good seed-bed. 



