82 ENTOMOLOGY. 



wings are thickened, folded roof-like over the body, while the young 

 are often covered with a white cottony mass. Psylla pyri Schmidt 

 injures the pear-tree; and P. tripunctata Fitch is common on pine- 

 trees. 



Family Membracidae. Head broad, prothorax very large and of 

 Varied form, being arched, compressed, hump-backed, conical, etc., 

 in different species, and often with spines and projections. Mem- 

 brads foliata (Linn.); Telamona monticola (Fabr.). 



Family Cicadidae. The Cicadae are among the largest of insects, 

 and besides their broad heads, prominent eyes, and well-developed 

 ovipositor, have, in the males, a musical apparatus at the base of 

 the abdomen, by which they produce a loud, shrill, piercing noise. 

 The family also comprises the longest-lived of all insects, the 17- 

 year Cicada (C. Yl-decim Linn.) requiring seventeen years to attain 

 its growth. A single brood appears only once in seventeen years in 

 the same given region, while there are three broods which appear 

 once in thirteen years. 



Family Fulgoridae. Antennae with only three joints; the forehead 

 or vertex enormously enlarged. Laternaria phosphorea (Linn.), 

 Surinam and Brazil; Fulgora candelaria (Linn.), the lantern-fly of 

 China, are both among the largest of insects. Native forms of much 

 smaller size are Otiowruscoquebertii'KiT-'by&ridDelphaxarvensisFitcli. 



Family Cercopidae. A large group of insects of medium or small 

 size, living in grass and on leaves; with a large broad thorax. 

 "Frog's spittle" insect, Ptyelus lineatus (Linn.). 



FIG. 69. Ptyelus lineatus. Spittle insect. , larva, enlarged; b, its natural 

 size; above it the mass of froth or " spittle." 



Family Jassidae. Slenderer insects than the Cercopidae, and with 

 longer hind legs, but like them living in grass and trees. Erythroneura 

 viiis (Harris), Diedrocepliala moliipes (Say). 



Sub-order 3. Heteroptera. The wings are in the true 

 bugs laid flat on the back, those of the fore pair thick- 

 ened on the basal half or two-thirds (hemelytra) ; the pro- 

 thorax is large and broad. Many species give out an offen- 

 sive smell, due to a secretion emitted from a gland situated 



