HEMIPTERA. 



I 39 



of the preceding species. This occurs in green-houses in the North, 

 and is also very destructive to orange-trees in Florida. 



Cochineal, Coccus cacti. — This is a native of Mexico, but is now 

 cultivated in India, Spain, and other countries. It feeds upon vari- 

 ous species of the Cactaceae, more especially Opuntia coccinilifera. 

 I have received living specimens which were collected upon a wild 

 cactus in Florida. The dye-stuff consists of the female insects, 

 which, when mature, are brushed off the plants, killed, and dried. 

 The entire insect is used. From cochineal, lake and carmine are 

 also prepared. Cochineal is now being superseded by aniline dyes, 

 which are made from coal-tar. 



Orthezia. — The members of this genus occur not uncommonly 

 on various weeds. They are remarkable for the calcareous secretion 

 with which the body is clothed. This is in the form of long plates. 

 Fig. 124 represents a nymph ; in the adult female, the excretion be- 

 comes more elongated posteriorly, and forms a sac containing the 

 eggs mixed with a fine down. Later, when the young are born, 

 they remain in the sac till the}- have themselves secreted a sufficient 

 amount of the lamellar matter to cover them. 



Fig. 124. — Orthezia, enlarged. (From the 

 Author's Report for 1880.) 



Fig. 125. — Icerya purchasi. Females, adult 

 and young, on orange. (From the Author's 

 Report for 1880.) 



Icerya purcJiasi. — This beautiful insect (Fig. 125* is one of the 

 most dangerous pests infesting fruit-trees in California. The body 

 of the adult female is scale-like, dark orange-red, and has the dorsal 

 surface more or less covered with a white or yellowish-white powder. 



The insect secretes a large egg-sac, which causes it to resemble l'ul- 



