126 Psyche [August 



about the same time. Both of these men gave interesting ac- 

 counts of their observations. In the fall of 1867 Shinier found 

 that many of the eggs under the scales were damaged by this mite, 

 and he described the shriveled, brown appearance of the egg shells 

 left by the mites. As Shinier and Walsh noted, the mites begin 

 to work at the caudal end of the scale, feeding on the eggs, and 

 gradually pushing forward beneath the scale. As the work under 

 the scale proceeds the sound eggs are devoured, and the brownish, 

 shriveled remnants of the eggs are thrust behind by the mites. 

 Late in the. fall, and in the spring, if these mites are abundant, 

 many a scale may be found with only the shriveled remains of the 

 eggs deposited there the summer before. 



Shimer evidently had a very favorable opportunity to watch 

 the work of this mite. In his notes dated September 15, 1867, he 

 says that one fourth of the eggs were then damaged, while on Octo- 

 ber 22 that same year, he found that nine-tenths of that year's 

 scales had all of the eggs destroyed by the mites, while not over 

 1% of them contained all sound eggs. 



Walsh (1868) gave an account in his characteristic language of 

 the manner in which a mite that he observed worked among the 

 eggs of the oyster-shell scale. From this account it is quite evi- 

 dent that the species in question was Hemisarcoptes mains. 



Lignieres (1893), whose careful work on this subject is the most 

 valuable contribution that we have on the subject, has the follow- 

 ing to say regarding the eggs that have been eaten by Hemisar- 

 coptes malus. 



* * * ils sont plus ou moins bosseles; souvent ils sont completement vides, 

 et les deux parois de I'oeiif, plus ou moins recroquevillees, ofl'rent une teinte jaunatre. 



The scale insects as well as the eggs are attacked by these mites, 

 as Lignieres observed. In one observation made at Ames the 

 beak of one of these mites was actually extracted from the scale 

 insect itself. This was done with a pin on the stage of a com- 

 pound microscope. Apparently the mite was attached by the 

 beak or mouth parts alone. In 1910 Hemisarcoptes was found 

 several times beneath oyster-shell scales where the scale insects 

 were present, but without eggs. 



Life History. Lignieres has already traced out the main de- 

 tails of the life history of Hemisarcoptes malus. Reference is here 



