\2 CIRCULAR 457, U. S. DEPT. OF AGRICULTURE 



All stem butts and discarded mushrooms should be carried away 

 and burned, or placed in a hole, then covered with quicklime or kero- 

 sene and a layer of earth. They should never be allowed to stand 

 about the house. 



When the house has finished bearing and is about to be cleaned 

 out, it should be allowed to dry out thoroughly and be fumigated if 

 possible. In any case, the spent compost should be hauled to some 

 distance from the houses and spread out thinly over the soil so that 

 the weather may destroy as many of the pests as possible. 



CONTROL OF MUSHROOM PESTS IN BEARING HOUSES 



After the beds have been cased, the temperature should be kept 

 rather low. For the best results it should be possible to maintain 

 an air temperature ranging from 50° to 55° F. A temperature be- 

 low 55° F. is more to be desired than one above that level, as the 

 lower temperature seems to be favorable for mushroom growth and 

 is low enough to retard materially the development of insect and 

 other pests of mushrooms. 



The purpose of the treatments and practices recommended in the 

 preceding sections is to prevent the infestation of beds. To date no 

 entirely satisfactory methods have been devised for the control of 

 insects and mites in the beds after the beds have been spawned. 

 The majority of the chemicals used for this purpose either do not 

 penetrate the beds deeply enough or they have a harmful effect upon 

 the spawn, which is very easily damaged. 



PRINCIPAL PESTS ATTACKING MUSHROOMS AND 

 METHODS FOR THEIR CONTROL 



Pests in mushroom plantings may be roughly divided into four 

 groups : Flies, mites, springtails, and miscellaneous. 



FLIES 



All things considered, mushroom flies seem to be the most destruc- 

 tive insects attacking the mushroom crop. The injury consists of 

 the feeding of the maggots upon the spawn in the beds and the tun- 

 neling into the stems and caps of the mushrooms, rendering them 

 unfit for use. No direct damage is done by the adult flies, but the 

 indirect damage they cause in transporting mites and disease organ- 

 isms from bed to bed and from house to house, while difficult to esti- 

 mate, seems to be nearly if not quite as important. 2 



Flies attacking cultivated mushrooms are of three general kinds, 

 known as mushroom flies or fungus gnats, manure flies, and gall 

 gnats. 



MUSHROOM FLIES OR FUNGUS GNATS 



There are at least four species of sciarid flies (of the genus Sciara) 

 that have been recorded as injuring cultivated mushrooms seriously 

 in the United States. Probably the most common of these is S. 

 pauciseta Felt. Others that have been noted as attacking mush- 



2 Charles, Vera K., and Popenoe, C. H. some mushroom diseases and their car- 

 riers. U. S. Dept. Agr. Circ. 27, 9 pp., illus. 1928. 



