424 



by heating to 150° F. or by fumigation with carbon bisulphide, used 

 in the strength of 2 to 4 lb. per 1,000 eft. of space. For destroying 

 the adults, the houses can be fumigated with tobacco or nicotine 

 preparations such as are used in greenhouses, the treatment being 

 made once a week during the bearing season. Dusting fresh pyrethrum 

 insect powder over the beds is also effective against the larvae, if 

 applied in time. 



Tyroglyphus liyitneri, Osb. (mushroom mite) is very prolific in 

 mushroom beds, feeding upon the plants in all stages and destroying 

 the mycelium. The life- cycle of the mite occupies only a few days, 

 so that its increase is extremely rapid. Under certain conditions the 

 hypopus or migratory stage is reached, the mite developing a hard, 

 chitinous covering, with short legs for walking, but lacking mouth- 

 parts. Sucking disks are provided on the ventral surface of the body 

 by means of which the hypopus attaches itself to some insect and is 

 transported to other breeding grounds. On arrival at a suitable spot, 

 the mite detaches itself from the insect, to which it has caused no 

 injury. In the hypopus stage the mite is capable of suspension of 

 vitality for an almost unlimited time, and in all stages is very difiicult 

 to control, being unaffected by fumigants or dust sprays. Prevention 

 is therefore the best means of control, and a compost thoroughly 

 infested should be destroyed and the woodwork of the house washed 

 with creosote or crude carbolic. The house should then be screened 

 against re-infestation by the mites. A predaceous Gamasid mite is 

 sometimes so numerous as to exterminate the pest, and does not 

 injure the mushrooms. 



Achoreutes armatum (springtail) is attracted to the manure used 

 in the compost and in cases of heavy infestation may entirely destroy 

 whole beds. Pyrethrum powder has been found fairly effective in 

 control, or fumigation by hydrocyanic acid gas at a strength of 3 to 

 6 oz. per 1,000 eft. This treatment should be given after picking, 

 as the gas injures the caps. 



Other mushroom pests dealt with are sowbugs, slugs and crickets. 

 As a general method of prevention against pests in the compost, the 

 author recommends sterilising the manure before planting in vats or 

 boxes through which steam pipes are conducted. The compost should 

 be heated to 150° F., which will destrov all animal life. 



Gillette (C. P.). Some Colorado Species of the Genus Lachnus.— 

 Ann. Entom. Soc. Atnerica, Columbus, Ohio, x, no. 2. June 1917, 

 pp. 133-146, 2 plates. 



The species described include Lachnus coloradensis, sp. n., which is 

 commonly found on Engelmann and blue spruces in Northern Colorado ; 

 it is a bark-feeder and is always found attacking the small limbs. 

 L. palmerae, sp. n., was taken on blue spruce and Picea engelmanni; 

 the injury is similar to that done by the previous species. L. braggi, 

 sp. n., taken feeding on the bark of twigs of blue spruce, Picea parryana 

 being apparently the only species attacked. L. tomeniosus, De Geer, 

 taken from needles of Pinvs radiaia and from P. scopulorum ; L. pomle- 

 rosae, Williams, taken on the bark of twigs of Pinus jMnderosa and 

 from P. scopulonini. 



