AMERTOAN HOMOPTERA. 869 



Sept. 15th. — The egg-laying season is drawing to a close; many of 

 the scales are full of eggs, the females drawn up towards the head ; 

 some of them brown, dry and so shriveled up as not to be observable 

 without close search. The eggs are placed somewhat irregularly, more 

 so at the posterior extremity. 



When examining a great number of scales, I find about one-fourth 

 of the eggs in a damaged condition; they are brown, or of a ferrugi- 

 nous color. In some of this year's scales all the eggs are thus brown. 

 A close examination proves them to have been dispoiled of their con- 

 tents, the brown remnants being the dry shells; the parasitic Acarus, 

 above noted, is among them, and sucking the eggs. These insects are 

 very small, and are lying quietly among the eggs, and about the same 

 'apparent size as the eggs. Hence, without close examination, may be 

 overlooked when exploring with a pocket-lens ; but close search will 

 prove them quite abundant, one or more under every scale thus being 

 dispoiled. They always begin to work among the eggs in the posterior 

 extremity of the scale, hence, I conclude that they enter from without, 

 at the opening at this extremity, left for the exit of the young Bark- 

 louse in the following summer. 



Oct. 13th. — I made a careful examination, and find many of the 

 Acari traveling slowly around on the bark of the tree — having dis- 

 poiled all the eggs in one scale they are out searching for others. Hav- 

 ing greatly multiplied during the last month, I can now find a hundred 

 where I found one a month ago. It is very interesting to behold this 

 great, and heretofore unheard-of, enemy of the Apple Bark-louse; truly, 

 every noxious insect has its enemies, although, like this, they may be 

 hard to discover. 



Oct. 22d. — I spent a long time in examining the eggs of the Apple 

 Bark-louse, and exploring the bark of the trees for the Acari; they are 



"When this insect is thrown over on its back on a glass plate, it is not able to 

 turn over. These Acari may readily be mistaken for young Bark-lice by the 

 naked eye or through a pocket exploring-lens, because each are very small, 

 whitish, slow-moving animals, and each have long, projecting, abdominal fila- 

 ments; but the detection of eight legs and the snout-like form of the head in 

 the Acarus, will be diagnostic marks, without a microscopic examination; and 

 the season of appearing is another feature. The color of the head and anterior 

 legs being about the same as that of the empty egg-shells, has raised the inquiry 

 in my mind — may not this color be derived from the juices of the eggs while it 

 is eating ? This, however, will remain mere supposition, for the Acarus is rather 

 too small to justify an attempt at "washing his face and hands." There is a 

 bare possibility that the natural color of the head and fore legs is whitish, like 

 the rest of the body. 



TRANS. AMER. ENT. SOC. (47) JANUARY, 1868. 



