BEPORT OF THE 8TATE ENTOMOLOGIST 



451 



Mites Infesting Potatoes. 



(Ord. Acarina: Fams. Acarid.k, Gamasid^e.) 



Some " scabby " potatoes received from Westchester county, N. Y., 

 had large cavities eaten into them, which were nearly filled with "thou- 

 sand-legged worms," Julus cceruleocinctus. Associated with them 

 were hundreds of mites occupying, and apparently feeding in, the cavi- 

 ties excavated by the millepeds. Examples of the mites were sent to 

 Prof. H. Osborn, of the Iowa Agricultural College, who is studying 

 these creatures, for his identification. He returned answer as follows: 



Food-habits of Rhizoglyphus. 



" The specimens I take to be a species of Rhizoglyphus, near or 

 identical with the R. (Tyroglyphus) phylloxera of Planchon and Riley, 

 the habits of which were recorded as very similar to this — feeding 

 upon the vegetable tissues of the roots infested with Phylloxerce. 



" I have seen examples apparently identical with this, in large num- 

 bers, in various vegetables and roots that were injured by insects or in 

 a partial state of decay, and I surmise that they feed mainly, if not 

 entirely, on decaying vegetable matter, although Riley reported them 

 as, when full-grown, preying upon the Phylloxerce " (Sixth Report on 

 the Insects of Jlissouri, 1874, p. 53). 



Associated with Potato Scab. 

 This mite is identical in appearance with a species of which a photo- 

 graph was sent me a few years ago by a correspondent in Eastern New 

 York, who claimed, and was very confident, that he had made the dis- 

 covery that it was the cause of the "potato scab." From this it may 

 be inferred that it is not infrequently an attendant on the scab disease. 



Other Mites in Potatoes. 



In Third Report on Insects of New York I have recorded the appear- 

 ance of two species of mites in cavities of potatoes associated with 

 Julus cceruleocinctus, one of which was Uropoda Americana Riley — 

 an occasional parasite of Jidus, and the other a vegetarian, apparently 

 undescribed, and for which, if it proved to be new, I proposed the 

 name of Gamasus obovatus* 



* Third Report on the Insects of New York — " Report to the Regents for the Year 1886, M 

 1887, pp. 133, 134. 



