THE ANGOUMOIS GRAIN MOTH 



347 



Carbon bisulfid is the commonly accepted agent for use with 

 all granary insects. This may be applied directly to the infested 

 grain, or, better, poured through a gas-pipe with the lower end 

 plugged and the sides at lower end perforated, the gas-pipe being 

 pushed down into the grain at different depths. The gas from 

 this liquid, being heavier than air, causes it to descend through 

 the mass. The effectiveness of this treatment varies with the 

 temperature. A temperature below 60 degrees F. renders treat- 

 ment with carbon bisulfid un- 

 desirable. Five pounds for 

 each 1000 cubic feet at 70 de- 

 grees or above is advised. The 

 gas formed is explosive; hence, 

 no exposed flame or spark of 

 any kind should be brought 

 near it. The burning of sulfur 

 is hardly effective. For more 

 particular directions regard- 

 ing the use of carbon bisulfid 

 in elevators and mills, see 

 page 61. 



Heating. Where possible, 

 heating a mill to a temperature 

 of 123 degrees F., and holding it 

 at that temperature for several 

 hours, has been known to kill 

 all insects in all stages found 

 therein. This has been called 

 the heat method, and, to be 

 successful, it calls for a special 

 plan of arranging the hot- 

 water or steam pipes. 



The Rice Weevil (Calandra oryza Linn.). This resembles 

 somewhat the granary weevil and has very similar habits. Their 

 life histories are nearly identical, although the rice weevil may 

 be found in fields remote from the granary. This beetle feeds on 

 rice, wheat, barley, rye, hulled oats, and buckwheat, and fre- 

 quently invades cracker boxes, cases of breadstuffs, bags of flour, 

 and barrels of meal (Fig. 353). 



For measures of control, see granary weevil and also page 217. 



The Angoumois Grain Moth. This pest is named from a 



FIG. 352. Flour matted together by web 

 spun by larvse of flour moth. (Lugger.) 



