20 



CIRCULAR 457, U. S. DEPT. OF AGRICULTURE 



their lighter color. After a period of growth and several molts, 

 these become capable of reproduction. Almost from the moment 

 they hatch from the egg they are capable of feeding upon and 

 damaging spawn and mushrooms. 



Springtails are usually brought into the houses with the compost, 

 but may enter later through cracks. For this reason it is important 

 that the surroundings of the mushroom houses be clean and free from 

 rubbish so as to offer as little refuge as possible to these pests. Al- 

 though they are capable of withstanding intense cold, they are easily 

 killed by heat. In the case of Lepidocyrtus lanuginosus, a springtail 

 found doing damage in commercial houses in Ohio, it has been deter- 

 mined that heating infested mushroom houses to a temperature of ap- 

 proximately 104° F. 

 for 10 minutes will 

 Mil the majority, if 

 not all, of them. 'For 

 this reason it. is im- 

 portant that the 

 houses go through 

 a good heat, and that 

 the bottom beds and 

 floor be also well 

 heated. Otherwise 

 springtails escaping 

 from the upper beds 

 will survive upon the 

 floor and b o 1 1 o m 

 beds and later rein- 

 f est the entire house. 



As in the case of 

 the mushroom mite, 

 springtails in the 

 beds are very diffi- 

 cult to control, since 

 insecticides do not 

 penetrate the beds 

 well, so only the insects upon the surface are killed. Sometimes, by 

 lightly spraying the beds with water 4 or 5 hours before treatment, the 

 springtails may be brought to the surface, and more of them killed by 

 subsequent applications of insecticides. 



Fumigation with calcium cyanide at the rate of 2 to 2% ounces 

 per 1,000 cubic feet of air space is also fairly effective. 



Some species of springtails have a habit of congregating in mush- 

 room houses at certain times in enormous numbers, looking like piles 

 of gray powder in the aisles. Whenever springtails are found con- 

 gregating in the aisles of a house they should be swept up and burned 

 or otherwise destroyed. 



MISCELLANEOUS PESTS 



A small mycetophagicl beetle, Litargus halteatus Lee, has become 

 a pest, during the last 2 years, in at least two mushroom establish- 

 ments in the West. Very little is known of this insect or of methods 

 for controlling it. 



Figure 8. — Two species of springtails that attack mush- 

 rooms : A, Lepidocyrtus lanuginosus, X 30 ; B, Achorutes 

 armatus, X 60. 



