MUSHROOM PESTS AND THEIR CONTROL 21 



The meal moth (Pyralis farinalis L.) was found feeding in the 

 spawn upon one occasion. The adults may be controlled by pyrethrum 

 dust mixtures and probably would never be of importance in houses 

 that are dusted regularly for fly control. 



Sowbugs, also known as "pillbugs" and "wood lice", are elongate, 

 convex, slate-gray crustaceans, with seven pairs of legs. Fully 

 grown specimens may be one-half inch in length. They occasionally 

 become numerous enough in mushroom beds to cause some damage 

 by eating holes in the buttons and in the caps of matured mush- 

 rooms. In a cellar or other small area it is possible to control sow- 

 bugs by hand-picking them off the beds. Where they congregate 

 in clusters along the edges of the beds, hot water may be poured 

 upon them. Pyrethrum dusts as used for the mushroom flies will 

 give some control if they actually come in contact with the sowbugs. 

 In using dusts, the beds should be allowed to dry slightly, and should 

 not be watered for approximately 24 hours after application of the 

 insecticide. Light fumigations with calcium cyanide when the sow- 

 bugs are feeding on the surface of the beds (usually at night) are 

 said to be effective. Poisoned baits are also effective against these 

 creatures, but their use in mushroom houses cannot be recommended 

 because of the danger of accidentally getting poison on the mush- 

 rooms. 



Slugs seldom become numerous enough to be of importance, but 

 where they do, hand-picking is the most effective remedy. 



Crickets sometimes become pests in mushroom beds by eating holes 

 in the caps. They are not difficult to discover and can be collected 

 by hand-picking methods and destroyed. 



