' CHAPTER IV 



LECANIXJE THE NAKED Oil WAXY SCALES. 



General Characters and L>fc-history. The Bark -lice of this subfamily 

 make no true scale. They are either naked or possess waxy coats ad- 

 hering more or less closely to tlic bodj of the insect, but not fastened 

 permanently to the bark. The development from the larva to the adult 

 female is apparently one of simple growth, and no molts have been ob- 

 served. The change in form takes place gradually and is due to the 

 swelling of the body as it becomes lilled with eggs or young, or to the 

 accumulation of the covering of wax. Eggs are deposited in a cavity 

 beneath the body of the mother, or are retained within her body until 

 hatched, in those species which bring forth their young living. 



The young change their position upon the plant at will, and this 

 freedom of movement is retained until near the end of their lives. The 

 insects, however, become more sluggish as they grow older, and at last, 

 in the incubating period, the legs and other external members of the 

 larva wither and the body becomes adherent to the surface of the plant. 

 No males have been discpvered in any of the species of the group which 

 come within the scope of this treatise. 



The newly-hatched young of the Lecanina3 closely resemble those of 

 the Diaspina3. They are active, six-legged creatures, with thin bodies, 

 oval in form. They feed in the same manner, by plunging their sucking 

 beaks into the cellular tissues of the plant, but the beak never grows 

 very long, and while active life remains the insect has power to remove 

 it and to reinsert it in afresh place. 



Two genera of Lecaninie fall within the scope of this work. 



In the genus Lecanium the insect makes no covering for itself or its 

 eggs, but the skin becomes more or less toughened with age, and finally 

 presents the appearance of a parchment-like scale. The species belong- 

 ing to the genus Ceroplastcs excrete a thick coating of wax, which wraps 

 the body of the insect above, but is easily removed from its surface. 

 Underneath the wax the skin of the Coccid is thin and tender. 



THE TURTLE-BACK SCALE BEOAD SCALE. 

 (Lecanium hesperidum, Linn.) 



. [Fig- 11-] 



Descriptive. The full grown Coccid is 3 mm to 4 mm (0.12 to 0.1C inch) 

 long, broadly oval, more or less swollen, arid convex upon the disk, sur- 

 rounded by a thin, flat margin with two shallow notches on each side 

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