ORDER HEMIPTERA. 



83 



ravages at various times in most of the vine-growing districts on 

 the Continent. 



The Aphides have the habit of discharging a sweet sticky sub- 

 stance called honeydew, of which ants are very fond. 



Fig. 116. — Lachnus Quescus (Mag.) 



The reproduction of the Aphides constitutes one of the most 

 interesting chapters in the history of the animal kingdom. 



Family 10, Aleyrodidce. — Many of the insects of this family re- 

 semble moths in appearance. Indeed, the typical species, Aleyrodes 



Fig. 117. — Aleyrodes Proletella (Mag.) 



proletella, a very small reddish insect, was formerly considered to 

 be a moth by the older writers on entomology. 



Family 11, Coccidce. — This family contains the Cochineal Insects, 

 the Scale Insects, and their allies. 



The Coccidce, or Scale Insects, are sometimes very injurious to 

 cultivated plants, but they are also useful, producing cochineal, 

 shellac, manna, and other substances of considerable importance. 



The Cochineal Insect {Coccus cacti) is a native of Mexico, and 

 furnishes us with the most valuable and durable red dye that we 

 possess, and the Lac Insect ( Coccus lacca), an East Indian insect, 

 produces the well-known lac-dye. 



