SCALE INSKCTS 



They constitute the family known as the Coccidae, and belong to 

 the Homoptera, which, is generally accepted by entomologists as a 

 division of the order Hemiptera. Other familiar examples of the 

 Homoptera are the plant-lice (Aphididae), the seventeen-year Cicada, 

 the vine leaf -hopper, and the tree-hoppers. The cochineal and 

 lac insects belong to the Coccidae. 



As there is considerable diversity of structure among the species 

 of Coccidae, this family has been divided into five sub-families. 

 One of these, the Bfachyscelinae, includes species which live in galls, 

 and are wholly confined to Australia. The four remaining sub-fam- 

 ilies may be ordinarily distinguished by the following table: 



1. Scale composed partly of .molted skins, and partly of a secre- 

 tion of the insect 



Scale composed of a secretion of the insect alone, or else absent; 

 never in part composed of molted skins ........... . '2 



2. Individuals usually fixed to plant on which they live ; the body 



of the female scale-like or rather globular, with segmen- 

 tation absent or indistinct ................ L<>canhi(t<>. 



Individuals usually retaining the power of motion ; the body of 

 female usually distinctly segmented .............. 3 



3. Abdomen never terminating in two long caudal filaments .... 



................................ Monophloebinae. 



Abdomen always terminating in two long caudal filaments . . 

 ....................................... Cocci n( ic. 



Diaspinae. Examples are the various species of Aspidiotus, to 

 which belong the San Jose scale, the greedy scale, and the red 

 scale of the orange in California. The genus Aspidiotus is distin- 

 guished by the female scale being circular, or nearly so, with the 

 exuviae either central or more or less marginal ; and the male scale 

 somewhat elongated, with the exuvia more or less central. The fe- 

 male scale may be distinguished by having two cast skins or exuviae 

 beneath it, while the scale of the male has but one. Near the cen- 

 ter of the scale, or between the center and the margin, will be seen 



