No abstract

Serritermitidae (Isoptera) is a small and little known Neotropical termite family which includes only two genera: Glossotermes and Serritermes. Despite the lack of detailed studies, it has been assumed that these termites have a true worker caste. A recent study revealed that Glossotermes has a linear development pathway and lacks true workers. Here, we present a study of the polymorphism of Serritermes serrifer Hagen & Bates, a species endemic to the Cerrado ecoregion of central Brazil which lives as an inquiline inside nests of Cornitermes spp. A morphometric analysis was performed based on measurements taken of 11 body parts of 544 specimens of immatures, worker‐like individuals, soldiers, and alates. Sex of specimens was determined by dissection and examination of the seventh sternite. A principal component analysis (PCA) was used to evaluate morphological changes during development. Contrary with previous information from the literature and similar to Glossotermes, Serritermes shows a linear development pathway with two larval instars, two sizes of pseudergates, and a single nymphal morph. Pseudergates apparently undergo stationary molts. Sex ratio among pseudergates is male‐biased, but not as strongly as in Glossotermes. Typical colonies have a single physogastric primary queen and a single primary king. Ergatoid reproductives are relatively rare and some female ergatoids may become strongly physogastric. Nymphoid reproductives were not found. All soldiers are male and bear well‐developed testes.

The present study investigated the caste differentiation system of Armitermes holmgreni in natural colonies from the Atlantic Forest in northeastern Brazil. Thirteen measurements were made of the termites encountered in three colonies. The morphometric differences among the instars were analyzed using principal component analysis (PCA). The differentiation patterns of the nymphal lineages of A. holmgreni agreed with earlier descriptions of species of the Termitidae family, with one larval instar followed by five nymphal instars and alates. Nymphoid neotenics became differentiated starting at the fourth or fifth nymphal instar. Two larval instars were observed in the apterous lineage before the appearance of workers, presoldiers, and soldiers. Both workers and soldiers had only one instar each. The A. holmgreni workers consisted of male and female individuals, without sexual dimorphism, a situation that had not been previously recognized among the Syntermitinae. The A. holmgreni soldiers consisted only of female individuals, a pattern observed in most species of Termitinae and Macrotermitinae. The differentiation of nymphoid neotenics starting at the fourth or fifth nymphal instar has also been reported for Armitermes euamignathus. The general patterns of differentiation of A. holmgreni were similar to those previously observed in other species of Syntermitinae.