186 ZOOLOGY. 



and Honduras. It is i^roLable that it would flourish in the southern United 

 States wherever the species of cactus suitable for its food are found, 

 Humboldt calculated the annual amount of cochineal imported into Europe 

 to be 800,000 jiounds, and it requires about T0,000 insects to make a 

 pound. Lac (or shell lac), which is used in making sealing-wax, varnishes, 

 etc., is the product of a coccus. Manna has a similar origin ; and a white 

 wax is collected from another species. Lecaniiiin {Jigs. 52, 53), Dorthesia 

 {Jig. 56), and Chermes {fig. 58), belong to this family. 



Fam. 2. ApJudce {figs. 57, 59). The plant lice, like the preceding 

 familj-, are small insects which infest the tender shoots of vegetables, and 

 by their numbers sometimes cause great damage. Tlie body is robust, the 

 head small, the antenna seven articulate, the feet slender, the wings trans- 

 parent, with few nervures, and the abdomen is sometimes provided with 

 two tubular stylets connected with glands bearing a saccharine liquid, upon 

 which the newly excluded young are said to feed, and which is eagerly 

 sought by ants. The Aphides are generally without wings, although they 

 are anomalous in sometimes having and sometimes being without them in 

 the same species. The apterous individuals are generally females. The 

 pupse are active, and can be distinguished by their incipient wings, unless 

 they are to produce wingless individuals. A single impregnation will 

 fecundate several generations, the offspring being females which are capable 

 of continuing the racer. Kyber thus continued a species for four years, 

 and Bonnet raised nine generations in three months. In some cases eggs 

 are produced, and in others living young, and of these about ninety are 

 produced at a time, 



Fam. 3. Psyllidm {fig. 55). A small family allied to the Aphides, but 

 they are more active. They have ten articulate antenna?, the females 

 have an ovipositor, and the male several abdominal appendages, 



Fam. 4. Cercojndce. This is an extensive and widely spread family of 

 small and handsome insects, which suck the juices of plants, and are found 

 abundantly in grass and low vegetation. The antennae are tri-articulate, 

 the stemmata two, the feet slender and adapted for leajDing, The larva of 

 Aphrophora {fig. Y-i) pierces small branches, and causes the saj) to exude, 

 which forms a mass of bubbles like spittle, under which the larva is hidden. 



Fam. 5. Mcmhracidce. This family is closely allied to the preceding 

 one in natural characters and habits, and is united with it by some 

 authors. The pronotum is dilated so as to cover the posterior part of the 

 body entirely or in j)art, forming a conspicuous object, and giving to some 

 of these insects a very strange appearance. 



Fam. 6. Fulgoridce. This family is remarkable for the large projecting 

 head, bright colors, and large size of some species. The Chinese Fidgora 

 candelaria {fig. Y6) is yellow, and the elytra black, marked with flavous 

 sj)ots. F. laternaria {fig. 77) inhabits South America. 



Fam. 7. Cicadidm. This family is named from the genus Cicada {C. 

 fraxini., pi. 80, fig. 75), which has attracted attention from a remote 

 period on account of the noise of the male. This sound differs consi- 

 derably in the different species, that of C. pj'imwsa, Say, for example, 

 390 



