478 



ARTHROPODA. 



The Arcbiptera were formerly united with the Neuroptera on account 

 of similarities of wings. The separation is due to cliaracters of mouth 

 parts and development. 



Sub Order I. CORRODENTIA. Larvse distinguished from the im- 

 agines by difference in size and, in the winged forms, by lack of wings. 

 Best known are tlie TermitidtE (Isoptera), or white ants, which must not 

 be confused with the true ants (Hymenoptera), from whicn they are dis- 

 tinguished by the similar body segments, the mouth parts, and the simple 

 development. Like the true ants, they have a well-developed social state. 

 A colony of termites, consisting usually of thousands of individuals, forms 

 a nest with numerous chambers and passages. They are nocturnal, and 

 they burrow, without coming to the surface, through old wood (timbers 

 of houses, furniture, picture frames, dead wood in the forest, etc.). They 

 line these chambers with a cement-like substance composed of refuse which 

 has passed through the alimentary canal. Many species build dome-like 

 nests, ten or fifteen feet high, fifteen to twenty or twenty-five feet across, 

 of chewed earth. In a colony are winged and wingless individuals, the 

 latter with ametabolous development (fig. 506). The wingless forms have 

 the sexual organs rudimentary, but, in contrast to ants and bees, may 

 belong to either sex. They are frequently blind, have strong mandibles, 

 and are of two kinds, the workers (c) and the large-headed soldiers (d). 

 The winged forms are sexually functional (6). Shortly after the metamor- 

 phosis they swarm, and then the wings are bitten off at the base and 

 ' king ' and ' queen ' either form a new colony or enter one already in 

 existence. After copulation the abdomen of the queen, by the formation 

 of numerous eggs, swells to an enormous size (e). Since the swarming 



Fia. .'JOe.— T'eT-mra /;<rj.//.,-.5,* white ant. (From Riley. 1 ,i, larva. ; 

 werlit'i- ; ((, siililier ; i\ ruieeri'; /, ]mpa. 



/), winffed male 



individuals form the prey of birds and other animals, it often happens that 

 a colony is left without a royal couple. In such cases the line is perpet- 

 uated by reserve males and females, sexual animals which have not com- 



