CHARACTERS AND CLASSIFICATION. . 65 



CHARACTERS AND CLASSIFICATION. 



The Coccidaa are a family of the sub-order Hemip- 

 tera-Homoptera, which includes also the Aleyrodidse, 

 Aphididse, Psyllidse, and Cicadse. Certain of these fami- 

 lies often bear a striking superficial resemblance to 

 each other, which is especially noticeable in the imma- 

 ture or stationary conditions of the Aleyrodidge ; and 

 among the Aphididae, Gerataphis latanise is frequently 

 mistaken for a Coccid, and is known among horticul- 

 turists as " the black seed scale." All the insects of 

 the order are characterised by the possession of 

 suctorial mouths, and, taken together with the Hemip- 

 tera-IIeteroptera, constitute the whole of the sub-class 

 Haustellata of the Insecta. 



The characters by which the Coccidse may be distin- 

 guished from the other allied families of the Homoptera 

 are as follows : 



LARVA. 



Larva minute, active. Male and female rarely 

 separable, usually naked ; tarsi as in the adults. 



FEMALE. 



(1) Wings always absent. 



(2) Head and thorax united, boundary line generally 

 indicated. 



(3) Tarsi generally monomerous with a single claw. 

 (In the abnormal genus Exzeretopus, Newstead, and the 

 gall-making Olliffiella, Cockerell, the anterior tarsi are 

 two-jointed.) 



(4) Mouth or rostrum placed on the ventral surface, 

 a little anterior to or behind the insertion of anterior 

 pair of legs. (It is absent in the adult females of the 

 exotic genus Mar gar odes.) 



(5) Metamorphosis incomplete. 







