PROC. ENT. SOC. WASH., VOL. 21, XO. 5, MAY, 1919 103 



Absence of Soldier Caste. 



The normal mandibulate soldier is lacking in some genera 

 of the higher termites, the Metatermitide. The "nasutus"- a 

 highly specialized sterile form with a "beak" -appears, or the 

 soldier caste is entirely lacking as in the genus Anoplotermes 

 Fritz Miiller, an "over specialization." Anoplotermes fumosiis 

 is apparently a "social parasite" in the sense that Wheeler (1918) 

 uses this term, since it is always found in the same colonies or 

 closely associated with other earth-inhabiting termites species 

 of Amitermes Silv., Constrictotennes or Reticulitennes. 



No wing pads have been found on mandibulate soldiers or 

 nasuti in Nearctic species of the family Metaiermitidae. The 

 nasutus is a highly specialized sterile caste and probably is 

 adapted to special functions in the colony life. The mandibles 

 of the nasuti of species of Nasutitermes Bks. or Constrictotennes 

 are rudimentary. In general, there is a more highly specialized 

 development of the mandibles of the soldier caste and a reduction 

 of the number of, or a complete loss of, the marginal teeth from 

 the lower to the higher termites. The soldier caste varies greatly 

 in both size and structure; soldiers are nevertheless apparently 

 not as effective combatants as the more numerous workers. 



The Frontal Gland. 



In the frontal gland, in the soldier caste, there is in general, 

 a progressive development from the genus Reticulitennes in 

 the family Mesotermitidae Holmg. where this gland appears 

 to be in active secretion and functional to the genera Xasittitennes 

 and Constrictotennes where the liquid exuded from the nasutus 

 or beak is probably for the purpose of defense; the mandibles 

 in the latter genera are rudimentary and are not functional. 

 In primitive species in the lower termites in the family Pro- 

 termitidae Holmg. the frontal gland is absent. 



This gland is of importance as a basis for systematic classifica- 

 tion of the winged adults. Holmgren (1900) has studied the 

 phytogeny of termites upon the basis of the morphology of the 

 frontal gland and has divided all the sexual adults into three 

 groups, according to whether the frontal fland has an opening 

 in the higher termites; no opening; or an entire absence of the 

 gland in the lower termites. 



BIBLIOGRAPHY. 



1893. Grassi, B., and Sandias, A. "Costituzione c Sviluppo della societa 

 dei termitidi, etc." Dagli Atti dell Acad. Gioenia di sci. nat. in 

 Catania, Vol. Vie ser. 4 Catania. 



