INSECTS INJURIOUS TO MEATS 



281 



food substances which they attack as opportunity affords. 

 They often occur in sugar, especially raw sugar, in great 

 numbers and are therefore sometimes called sugar mites. 

 It is these tiny mites (Fig. 94), abundant at times in 

 grocery stores, that cause the disease known as "grocer's 

 itch." The malady is induced by the presence of the 

 mites on the hands of those 

 working among mite-infested 

 food products. The materials 

 attacked by these pests in- 

 clude flour, hams, dried 

 meats, sugar, cheese, hair in 

 furniture and mattresses, 

 grains, cereal foods, drugs, 

 dried fruits, seeds, bulbs, 

 roots, and feathers. One 

 species, at least, is a serious 

 pest of mushrooms. We 

 have seen mites exceedingly 

 abundant in the manure 

 about to be placed in spawn 

 beds. Whether these mush- 

 room mites originate in the 

 manure used in the beds or 

 not we dare not say. At 



any rate, manure is often infested with them and some 

 mushroom growers have attempted to fumigate the 

 manure with hydrocyanic acid gas before using it. 



The life history and transformations of these mites 

 are most remarkable and interesting. All of them lay 

 eggs, which they scatter irregularly over the material upon 

 which they are feeding. The young mites that hatch 



Fig. 91. — A common cheese mite 

 (T. longior). (X 60.) 



