MUSHROOM ENEMIES 



open fields and woods larva-infested mush- 

 rooms are frequent, but in a properly regu- 

 lated mushroom cellar this condition is most 

 infrequent. This is due to the fact that 

 these insects are practically inactive at 

 temperatures below 55° F. In fact, if they 

 cause damage at this temperature it is more 

 to the spawn than to the mushrooms. If the 

 eggs have been deposited in the compost 

 while the temperature is still high the flies 

 will emerge in time, but little damage will 

 be done. From what has been said it is 

 obvious that proper control of conditions 

 will usually result in perfect control of this 

 pest. On the other hand, when spawn is 

 planted in late summer with the idea of hav- 

 ing the crop come into production early in 

 the autumn these pests may be a serious con- 

 sideration. The adult flies are readily 

 killed by fumigation with tobacco or any 

 of the various trade nicotine fumigants, em- 

 ploying the amount of material commonly 

 recommended for greenhouses, the indica- 

 tions for which are furnished with the ma- 



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