678 



CLASS IV. INSECTA. 



Termitidae, and Mallophaga in a single order Corrodentia. 

 making the Psocids a special sub-order Copeognatha * The 

 group is also of interest from the fact that very many members 

 of it are preserved in amber. There is but one family : 



Fam. 1. Psocidae. With the characters of the Order. Psocus, many 

 species of this genus live in colonies on the rough, lichen-covered bark of 

 trees. They spin silken webs which cover the colony and lay their eggs 

 in clusters which they protect with a coating of chewed woody fibre. 

 Thyrsophorus from Brazil is the largest genus measuring an inch across 

 the outstretched wings. Embidopsocus is said to show affinities with the 

 Embiidae. Clothilla and according to others A tropos share, with the Beetle 

 Anobium, the credit of being death-watches. Their tappings alarm the 

 superstitious, though it is not absolutely proved that they cause the regu- 

 larly repeated noise. Both the last named species are " book-lice," and 

 by eating the starch paste employed in book-bindings and in lining insect 

 cabinets, cause much annoyance to librarians and entomologists. If 

 undisturbed they may exist in great swarms. 



Order 9. ISOPTERA (TERMITIDAE). f 



Social insects with or without wings ; when present all the wings 

 lie flat on the back ; hind- and fore-wings are alike membranous 

 and much longer than the body ; they are readily cast off, and break- 

 ing along a weakened line, leave a small projection behind ; the 

 ten abdominal segments end in a pair of short cerci ; metamorphosis 

 slight and gradual. 



The termites are popularly known as white ants, a misleading 



name as they are 

 not ants and by 

 no means always 

 white. The head 

 is large and in 

 some grades of 

 their communi- 



ties gigantic ; it 

 may bear com- 

 pound eyes and at most two ocelli, but many termites are blind. 

 The antennae have nine to thirty-one segments (Fig. 492). 

 The skin is usually thin even where the chitin is best developed, 



* Zool. Anz., vol. xxvi, 1903, p. 423. 



t Grassi and Sandias, Atti. Ace. Gioen., vi, 1893, and vii, 1894. Hagen 

 P. Boston, Soc., xx, 1878, p. 118. Lespes, Ann. Sci. Nat. Zool. (4), v, 1856, 

 p. 227. Grassi, Zool. Anz., xii, 1889, p. 360, and Q.J.M.S., xxxix, 1896, 

 p. 245. 



FIG. 429. Male of Termes lucifugus. 



