412 



THE INVERTEBRATA 



Fig. 306. Forficula auricidaria. Male. From Imms, after Chopard. 



Order ISOPTERA (Termites or White ants) 



Social and polymorphic insects with biting mouth parts ; four-lobed 

 ligula; wings very similar, elongate and membranous, capable of 

 being broken off along a line at the base ; cerci short ; metamorphosis 

 slight. 



The animals of this order abound everywhere in the tropics. Like 

 the true ants they have types of individuals (castes), specialized for 

 the purpose of reproduction, labour and defence (Fig. 307). The 

 termite community usually contains a dealated royal pair, the king 

 and queen, who are the founders of the colony, and also supplementary 

 reproductory individuals of two kinds: {a) winged, which normally 

 serve for the formation of new colonies, and (^) wingless, which become 

 capable of reproduction if occasion demands. There is usually a vast 

 number of individuals of sterile wingless forms belonging to two castes , 

 the workers and soldiers. The termite nests may be merely series of 

 burrows in trees, dry timber or in the ground, or they may be huge 

 mounds made of earth cemented together with the saliva of the termites . 

 Those living in the ground excavate the soil of the tropics, turning it 

 over and enriching it just as earthworms do in temperate regions. 



Their food consists chiefly of wood and other vegetable matter and 

 many species are extremely harmful, e.g. Neotermes, which damages 

 structural timbers, and Calotermes militarisy which bores into ^nd does 

 much harm to tea plants in Ceylon. 



The winged sexual forms in several colonies usually swarm at the 



