THE TDRTLE-BACK SCALE. 



49 



and one deeper indentation behind. The color changes with age from 

 transi):irent y?llo\v in the young to deepening shades of brown in the 

 adulr. Individuals attarke*! bj* parasites turn black. Until it becomes 

 gravid and swollen with young, the insect is exceedingly thin and trans- 

 parent, the green cdIot of the leaf or bark showing through the body so 

 that the very youiig Coccid is well nigh invisible. The surface is smooth 

 and shining, with faint, scattered i)uncturesou the disk. The six slender 

 legs are concealed beneath the dilated margins of the bo<ly. The male, 

 altliougli for many years diligently sought, both in this country and 

 abroad, still remains undiscovered. 



Yoitnfj L'O'va. — The newborn 

 insect lias the usual oval form of 

 young Baik-lice. It is yellowish 

 in coloi', and has a pair of six- 

 jointed anteujiai, and two long 

 bristles at the anal extremity. 



Metamorphoses. — The metamor- 

 phoses which take jilacc in this 

 species are very simjile, and con- 

 sist in a flattening and broaden- 

 ing of the form of the larva, and 

 in the gradual loss of external or- 

 gans by disuse. The first to dis- 

 appear are the antennae and the 

 anal bristles; lastly, but not until 

 the body becomes swollen with 

 young, the legs become; useless, 

 and are imbedded in the excre- 

 tions, which finally cement the 

 insect to the surface of the i)lant. 

 The body of the mother in this 

 last stage of her existence bo- 

 comes a casket tilled with the 

 young lice. These in due time 

 swarm forth together and distri- 

 bute themselves over the plant. 



liestnctiin to young Growth. — The young lice invariably settle upon 

 the bark and leaves of tender growth. Even the adult insects do uc'i 

 appear able to jiierce with their beaks the tissues of the plant when 

 hardened by age, and only the gravid and incubating females are found 

 upon parts which have completed a season's growth. 



Gregarious Habits. — There is a tendency in the young to ke». p together, 

 and at seasons when the Orange is in active growth, wIku the [)'ant is 

 pushing out an abundance of shoots, the swarming larvte do not need 

 to wander far iu search of f>od. The progeny of each female then set- 

 tle down together, and extensive colonies are formed. These colocdes 

 0521 o 1 4 



Fio. 11. — T.ecan'ium hexperidvm (T.inn.) Adnit fe- 

 malcii, uu Oruiijif, uuuiiul aizo. (Aficr Couiittock.) 



