1912] Eicing and Webster — Mites Associated ivifh the Oyster- Shell Scale 133 



Tetranychus telarius Linne. 



This species is found frequently in any one of its stages among 

 the scales on the bark of the trees, and for this reason might be 

 thought to be preying upon the scale insects or their eggs. We 

 noticed it commonly at Ames. This, however, is a plant feeder, 

 as are all the members of the family Tetranychidce, and it is in 

 no manner connected with the oyster-shell scale. As a rule these 

 mites confine their attacks to the leaves of the trees, but espe- 

 cially during the dormant period, many of them take refuge upon 

 or under the bark, where they may occasionally suck some nourish- 

 ment from the bark. 



Oribata sp. 



Upon examining trees infested with the oyster-shell scale we 

 frequently found nymphs of a species of Oribatidse moving slowly 

 over the surface of the bark, or sometimes inside old empty 

 scales. As we did not succeed in rearing any of these nymphs 

 to maturity, no specific determination could be made. They are 

 more or less scavengers in habits, eating bits of decaying organic 

 matter and frequently fungi. These mites are never predaceous 

 or parasitic. 



BIBLIOGRAPHY. 



1852 Laboulbene, Alexandre. Bull. Soc. Ent. France, p. 54. Original descrip- 

 tion of Monieziella (Acarus) entomophaga. 



1868 Shinier, Henry. Trans. Amer. Ent. Soc. Vol. I, p. 368. Original descrip- 

 tion of Uemisarcoptcs (Acariis?) mains. Account of its injury to the eggs 

 of the oyster-shell scale. 



1868 Walsh, B. D. First Rep. State Ent. 111. p. 44. Account of mites found 

 beneath the oyster-shell scales. 



1873 Riley, C. V. Fifth Rep. Ins. Mo. p. 87. Notes on mite enemies of the oys- 

 ter-shell scale. Gives a figure of Monieziella, but the description which 

 refers to the figure applies to Hemisarcoptes as well as to Monieziella. 



1877 Murray, Andrew. Economic Entomology, Aptera. South Kensington 

 Museum Science Handbook, pp. 97-102. Gives several figures of Tet- 

 ranychus telarius, and ample notes on its habits and its varieties. 



1893 Lignieres, Joseph. Mem. Soc. Zool. France, tome V, pp. 5-9,5. Discusses 

 habits of Monieziella entomophaga (here called Tyroglyphus malus) and of 

 Hemisarcoptes viahis (called Hemisarcoptes coccisugus). The first species 

 is found to be a scavenger only, while the second is the real enemy of 

 the oyster-shell scale. 



