80 



to discover and describe in the winged state, and which I found to be 

 carried home by certain Ants to the nests inhabited by the young 

 larvae of these Ants, for the sake of the sweet, woolly matter secreted 

 by them, and thence carried back again to the roots on which they 

 fed — just as a dairyman drives his cows up to be milked and then 

 drives them back again to pasture.* Both these species are quite dis- 

 tinct from the Apple-root Plant-louse; and I am acquainted with 

 several others, but only in the wingless state, which are also quite 

 distinct from that insect. As to the true "Woolly Plant-louse" of 

 the Apple-tree, the European entomologist Blot says, that "it can only 

 live upon the Apple-tree, and if transplanted upon any other tree, 

 it very soon perishes. (Arayot and Serv., Heniipt., p. 610.) 



What is probably the wingless female FORisr of this Apple-root Plant- 

 louse measures, when fully grown, about 0.07 inch long, at Avhich time, after 

 removing the white down, it is of a dull load color. The antennae are indis- 

 tinctly 6-jointed, with the length of the joints proportioned nearly as 2, 2, 4, 

 2, 2, 3, the last joint including a short terminal seta (unguiculus) . The 

 beak extends to the base of the middle legs. 



The color of the young larva is dull yellowish, as described by Fitch. 

 The antennte are indistinctly 5-jointed, the joints nearly equal, joint 3 a little 

 the longest, and 5 with a minute terininal seta. When the larva is very young 

 indeed, the beak is longer than the body, and projects behind so as to re- 

 semble at first sight, the honey-tube of the genus Aphis and its allies. When 

 older, the beak is about two-thirds as long as the body. 



I have not yet obtained the winged form of the female; but a full 

 description of it is given by Fitch. It occurred in New York on October 29th. 

 (AT. Y. Rep. I. pp. 9—10.) 



After a group of these lice has been stationed on a root in the 

 open air for two or three days, they become completely enveloped in 

 a white cottony mass, the filaments of which are five or six times as 

 long as the insects themselves, and, though somewhat crinkled and 

 irregular, radiate in general from the body of the insect as from a 

 centre. Attached to this mass may almost always be seen one or 

 two globules of sap, such as we often meet with rolling about among 

 the powdery matter secreted by the plant-lice that inhabit "Galls." 

 Dr. Fitch figures and describes the cottony matter as protruding only 

 from the tip of the abdomen of the larva; {N. Y. Rep. I. p. 9;) but 

 in reality it proceeds in an infinity of very fine filaments from the 

 general upper surface of the insect, though perhaps, as stated by Mr. 

 Eiley, it is secreted rather more densely on the hinder portion of the 

 back. Most certainly it is not secreted exclusively either from the 



^See Proc. Eut. Soc. Phil. I. pp. 307 — 8; and Trans. 111. State Agr. Soc. 

 V. pp. 493—4. 



