Are worker’s morphological characters enough to identify trophic groups in Termitidae?
Tarik Godoy Dangl Plaza, Tarik Godoy Dangl Plaza , Eliana Marques Cancello , Rogerio R. Silva
Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil ; Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil ; Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil ; Museu Paraense Emilio Goeldi, Brazil
Termites are one of the most abundant arthropods in soil of tropical ecosystems. They play important roles in decomposition process, nutrient cycling, nitrogen fixation, carbon flux, incorporation of organic matter in the soil and soil structuring, and are considered ecosystem engineers. The fundamental food source are cellulose and lignin in a gradient of humification, such as live, dry and advanced decomposition wood, grasses, fungi, lichens, dry leaves and soil or humus. Many ecological studies have classified termites them into ecological groups, most in trophic groups. Considering that the presence of the workers without any field information is common in collections, we try another way to identify trophic groups based only on encoded morphological characters of workers. We have studied the termite fauna sampled in the Termite Monitoring Program of Jirau, along the Madeira River, in Rondônia state of Brazil, Amazon Forest. Working with 97 species in 38 genera of Termitidae, we constructed a character matrix, consisting of: four characters of the mandibles, six of the maxilla, 13 of the enteric valve and other four of the digestive tube. To identify which variables are most important we have used a correlation matrix of Cramer's V and sequentially we did a chi-square test. After removing the least important variables, we generated a cluster with Gower similarity index. Some phylogenetic clades were recovered, such as the Apicotermitinae and most genera of Syntermitinae, which appear roughly in two groups (Syntermes + others genera), and species of the same genus appeared in the same cluster. However, our preliminary results indicate that this set of morphological characters from workers was not enough to recover termite trophic groups, such as litter feeding, humus feeders and xylophagous. This is a study still in process, and more characters will be included to try to understand the importance of the worker morphology in the tropic groups.