i8o 



The Orders of Insects 



tunnels or galleries of web wherein the insects live. They feed on 

 vegetable matter. Only about twenty species are known, and the 

 family is confined to the warmer regions, ranging north only to 

 Southern Europe and the Atlantic Islands (3, 112, 113)- 



Termitidae. — The Tirmh'ulce are in many respects like the Em- 

 biidx, but are not so narrow and elongate in form. The head is 

 large and may be provided with compound eyes and two simple eyes, 

 but many forms are quite blind. The number of antennal segments 

 varies between nine and thirty-one. The maxillse of the second 

 pair are joined together, but a median channel marks the line of 

 their fusion. There are three distinct thoracic and ten abdominal 

 segments, the hindmost, with a pair of short cercopods of several 

 joints (fig. 96 /', c). The wings of the two pairs are closely alike, 

 each is provided with three principal longitudinal nervures — the 

 sub-costal, median, and sub-median, which give off many branches. 

 The most characteristic feature of Termites' wings, however, is 



Fig. 98. — Head of Termite. a. front view ; b. back view, showing jaws. 

 Magnified 20 times. From Marlatt, Bull. 4 (n.s.) Div. Ent. U.S. Dept. Agr. 



the presence of a transverse suture or line of weakness close to the 

 root. After flight the wings are shed by a rupture at this suture 

 (fig. 96 a, d). 



Termites live together in large social communities which consist 

 of " kings" and " queens" — fertile males and females which after 

 the nuptial flight have cast their wings — and infertile males and 

 females ("soldiers" and "workers") in which wings are never 

 developed. They feed on wood and waste substances, and con- 

 struct earthern tunnels and galleries, often forming large nests. 

 The "queen" termite, with her enormously swollen abdomen, 

 whereof the segmental sclerites become widely separated by vast 

 tracts of membrane, is one of the most remarkable of insects (see 

 fig. 178). Termites are confined to the tropical and warmer temper- 

 ate regions, being quite unknown in these countries (3, II3). 



Psocidae. — The Psodda are small soft-bodied insects. The head 



