MUSHROOM PESTS AND THEIR CONTROL \Q 



several attempts to rear them beyond the first nymphal stage upon 

 spawn have been unsuccessful, so it is probable that the activities of 

 this species are almost entirely confined to the surface of the mush- 

 room beds. They damage mushrooms by chewing off the feeder roots 

 of the growing mushrooms, causing the stems to constrict at the 

 base, and injuring or killing the developing mushroom. 



Sanitation and prevention of infestation are the best methods of 

 avoiding damage by these mites. The mites are easily killed by 

 heat, having been found to succumb to 100.4° F. for one-half hour 

 at a relative humidity of 89 percent. If the temperature along the 

 floor does not reach this height, however, the mites in that location 

 will recover and reinfest the beds. They are very active and are 

 capable of crawling into cracks in the floor and walls to escape the, 

 heat. 



Since these mites are found chiefly on or near the surface of the 

 beds, the control measures recommended for the mushroom mite 

 should be effective against them. 



In addition to the two mites mentioned above, Rkizoglyphus phyl- 

 loxerae Riley and Histiostoma sp. have occasionally been noted as 

 attacking mushrooms. The control methods used against the other 

 species of mites would probably be equally effective against these two 

 species. 



SPRINGTAILS 



Springtails are, in general, very small, gray, blackish, or brown 

 insects, ranging from about one sixty-fourth to one-sixteenth of an 

 inch in length. Beneath the abdomen of each insect there is a 

 powerful springlike appendage which, when released, is capable of 

 hurling the insect through the air for a distance many times its 

 own length. In a wild state springtails live normally in damp 

 places beneath rubbish and leaves, and most of them feed upon 

 fungi. It is probable that any of these "wild species", when once 

 introduced into the mushroom houses, might prove to be serious 

 pests. A number of species of springtails are found frequently in 

 mushroom beds. These include Achorutes armatus Nic, Priostoma 

 minuta Tull., P. simplex Fols., Entomobrya sp., Xenylla welchi Fols., 

 X. humicola (O. Fab.) Tull., Lepidocyrtus albicans Reiit., L. cyan- 

 eus Tull., L. cyaneus var. cinereus Fols., and L. lanuginosus (Gmel.). 

 All of these are capable of doing damage to spawn and mushrooms 

 throughout the season. Two of these springtails are shown in 

 figure 8, A and B. 



Some growers have the idea that the presence of springtails in the 

 houses is to be desired ; in other words, that springtails in numbers 

 are an indication of a good crop. This is possibly true to the extent 

 that conditions favorable to springtails also favor the growth of 

 mushrooms, but it is also true that these same favorable conditions 

 may allow the springtails to multiply fast enough to reduce the crop 

 materially. Springtails inflict damage by eating the spawn and by 

 chewing holes in the stems and caps of the mushrooms. These pests 

 are so_ easily overlooked that the grower frequently attributes the 

 reduction in yield to some other cause. 



The life history of these creatures is very simple. The minute- 

 spherical eggs are laid in groups in the compost or spawn. They 

 hatch in about 10 days into minute replicas of the adults except for 



