402 Tachardiince . 



CHAPTER X. 

 Sub-family TACHARDIIN.E. 



Contains the single genus Tachardia, the characters of which will, conse- 

 quently, stand for those of the sub-family. 



Gascardia, at one time included in this sub-family, is now known to be a 

 Lecaniid — allied to Ceroplastes. 



Genus TACHARDIA, R. Blanchard. 



Carieria, Sign., Ann. Soc. Ent. Fr., (5), Vol. IV. p. loi (1874). 

 Tachardia, R. Blanch., Zoologie Me'dicale, Vol. I. (1886). 

 Tachardia, Sign., Bull. Soc. Ent. Fr., (6), Vol. VI. p. Ixii (1886). 



The genus, as originally erected by Signoret in 1874, was called 

 Carteria ; but that name having been preoccupied by Diesing, in 

 1865, for a genus of Protozoa, is now superseded by Tachardia, as 

 designated by Blanchard in 1886. 



The species, of which some thirty have been described, have 

 peculiar characters that distinguish them from those of any other 

 sub-family. The most noticeable of these (in the adult female) are 

 the distinct caudal extension, carrying at its extremity the anal 

 orifice ; a prominent dorsal spine, situated immediately above the 

 base of the caudal extension ; and a pair of more or less prominent 

 stigmatic processes — the so-called ' lac tubes ' of earlier authors, 

 whose function is, however, quite unassociated with the secretion of 

 the resinous product known as ' lac' All these organs are described 

 more minutely below. 



The popular name — ' Lac insects ' — by which species of this 

 genus are commonly known, indicates another character that is 

 common to all of them, namely, the production of a hard resinous 

 secretion (soluble in alcohol) which completely envelops them, 

 either in the form of separate cells or as a more or less continuous 

 incrustation in which the insects are embedded. The latter arrange- 

 ment really consists of a mass of confluent cells. The resinous cells 

 — or tests — when isolated, conform approximately to the shape of 

 the contained insects, but may be sculptured or diversely moulded 

 externally {e.g., cojichiferata, mimita, decorella). The cavity of each 

 cell communicates with the surface by three small apertures, two of 

 which are associated with the stigmatic processes, the third being 



