Neotropical Nasutitermitinae (Isoptera: Termitidae): a preliminary morphology-based phylogenetic analysis supports three new nasute genera

CARRIJO, T.F.; CUEZZO, C.; CANCELLO, E. M.

Dresden

Encuentro; 6th Dresden Meeting on Insect Phylogeny; 2013

Nasutitermitinae (Isoptera, Termitidae) is a well corroborated monophyletic group with a worldwide distribution, having a high richness of both genera and species, and the widest diversity of feeding and nesting habits. The subfamily is represented by 28 genera and 161 species in the Neotropical region, and it is always one of the most dominant groups in South American termite surveys. The genus Nasutitermes was never revised, and its taxonomy is quite confuse, so the identification of the Neotropical species is not always easy. During the study of type material of Neotropical Nasutitermes species deposited in different Isoptera collections, some morphological inconsistencies in relation to the general ?Nasutitermes pattern?, mainly in the worker digestive tube was found; thus, suggesting that these species should be removed from Nasutitermes. In order to reconstruct the phylogenetic relationships among Neotropical Nasutitermitinae genera and test the monophyly of Nasutitermes, a preliminary cladistic analysis involving the type species of all Neotropical Nasutitermitinae genera was conducted. According to the previous evidence of Nasutitermitinae relationships, two species of Syntermitinae (Cornitermes cumulans and Procornitermes striatus) and two of Termitinae (Amitermes amifer, Microcerotermes strunckii), were choose as outgroups, with A. amifer rooting the trees. A matrix with 83 characters was analyzed under parsimony criteria with TNT 1.1, using the ?new technology search? under default settings. Analyzes were performed with equal weights, as well as with implied weights with concavity factor ranging from k= 6 to 15. Some multistate characters were treated as additive. For the cladogram branch support, the relative Bremer support was calculated and a symmetric resampling was performed. The analysis under equal weights produced six equally most-parsimonious trees (642 steps), while with implied weights produced three different topologies for the range of values of k. In all the topologies the species N. gagei, N. robustus and N. hubbarti let the genus Nasutitermes paraphyletic. These species are differentiated mainly by the worker characters, particularly those of the digestive tube in situ (dorsal torsion, isthmus and U-Turn) and the mandibles. In this way, our preliminary results support the designation of three new genera which includes species previously described as Nasutitermes.