The phylogeny of termite genera based on imago-worker mandibles. Bulletin of the AMNH ; v. 95, article 2

p. 41-86 : ill. ; 27 cm.Includes bibliographical references (p. 85-86)."One. The phylogeny of 139 out of a total of 142 genera and subgenera of termites based primarily upon the imago-worker mandibles has been studied. 2. The imago-worker mandibles of termites provide a conservative morphological character significant for the study of phylogeny. 3. The families Kalotermitidae and Rhinotermitidae have a relatively fixed mandibular pattern in the imago and worker castes. The Hodotermitidae and the Termitidae exhibit a great variation in the imago-worker mandibles. The variation of this character within a genus is negligible. 4. In the main, this study corroborates the termite classification proposed by Holmgren. In some cases, however, he has misinterpreted the phylogeny because of convergent adaptation. The study of the imago-worker mandibles has cleared some of these errors. 5. The subfamily Serritermitinae, hitherto included under the family Rhinotermitidae, is transferred to the family Termitidae. 6. It is concluded that the Rhinotermitidae arose from a stock which had Archotermopsis-like imago-worker mandibles and possessed ocelli and not from the Kalotermitidae as suggested by Holmgren and Hare. 7. There are several phylogenetic lineages in the Nasutitermitinae, and Holmgren's subgenera are best raised to generic rank. 8. Pseudomicrotermes, whose exact relationship has thus far remained obscure, is now assigned to the subfamily Armitermitinae in which it forms a distinct group with Eremotermes and Synhamitermes. 9. There are several instances of convergence in termite evolution. The phragmotic head in the Kalotermitidae has evolved three times. The nasute soldier in the Nasutitermitinae has arisen twice independently. The evolution of the asymmetrical soldier mandibles in the Termitinae has occurred in two distantly related groups of genera. 10. Zoogeography has been of some help in understanding the phylogenetic relationships of several genera. The distribution of some primitive termites belonging to the families Mastotermitidae and Hodotermitidae conforms to Matthew's theory of distribution of primitive forms. 11. The worker caste, usually considered of little importance in termite taxonomy, can be of great value for generic identification, particularly by the study of its mandibles. 12. A discussion of the concepts of homology, conservative characters, convergence, Dollo's rule of irreversibility of evolution, regressive evolution, and the persistence of genes and gene patterns has been included"--P. 80