LAOHNUS. 4S 



species known in this family of insects. They are 

 noticeable on account of their varied habits and life- 

 history, and also for their ornate characters. Whilst 

 some kinds confine themselves to the soft rind of the 

 young branches of trees and shrubs, others find sus- 

 tenance within the crevices of the hard cortex of the 

 oak, the willow, or the pine-tree. 



Most species are clothed with a dense fur-like coat 

 of thick hair, which circumstance suggested to Illiger 

 the name Lachnus, which implies such a character. 

 Often this protective covering is supplemented by the 

 peculiar flocculent matter seen so remarkably plentiful 

 in Phyllajjhis. Another characteristic of this genus 

 is the development of the legs, which are robust, and in 

 the hind pair attain to a great length. The hind tarsi are 

 distinctly biarticulate, the last joint with the claws being 

 much more developed than is seen in Aphis proper. 



The rostrum is abnormally long. This development 

 is most remarkably seen in the rare species Stomaphis 

 quercuSj which exhibits the organ more than twice and 

 a half the total length of the body. Considered as a 

 proboscis, this insect has proportionally the longest of 

 all known animals. 



The nectaries are in some kinds almost obsolete, 

 but others~possess them very small, and expanded as 

 to their mouths. 



The tail is almost wanting, in accordance with Kal- 

 tenbach's remark, that this organ in its development 

 has a direct ratio to that of the cornicle. But although 

 these nectaries are so short, they do not preclude the 

 insect from the elaboration of honey-dew, for no 

 Aphides are more prolific in this secretion than the 

 LachnincB. On this account their presence on the 

 trunks and branches is often betrayed by the long file 

 of ants coursing up and down in quest of the liquid 

 with which they so much like to gorge themselves.* 



* The sweet substance found in quantity on some plants in Italy, and 

 known as manna clei apicollori, is considered by Cannestrini and otbers 

 to be tlie product of certain Lachnina. Targioni-Tozzetti gives a 

 chemical analysis of this secretion in the * Bull. Ent. Ital.,' ix, p. 240. 



VOL. III. 4 



