Paper of the Month September: Environment Evolution of termites to achieve global diversity

04/09/2023

Termites colonize nearly all landmasses on Earth, with the greatest diversity found in the tropics. Many termites are destructive pests of timber, yet not all are able to degrade wood. In fact, some of the most diverse termite groups have evolved the ability to feed only on soil particles, which represents a novelty in evolution. The study of such groups of termites is important to revealing interesting adaptations to this way-of-life, and is explaining how termites may have attained their global diversity. The genus Verrucositermes studied at BAM is one such example, characterized by peculiar outgrowths on the head capsule, antennae and mouth parts. These are not found in any other termite, and have now been described in detail for the first time. These outgrowths could be linked to the presence of a new organ, the rostral gland, that releases a substance in the environment, and whose structure has remained unexplored. We investigated the ultrastructure of the epidermal layer of the head capsule of Verrucositermes tuberosus soldiers and describe the ultrastructure of the rostral gland, which consists of a specific type of secretory cell. These contain organelles that provide secretions to the surface of the head, likely made of peptide-derived components. However, the function of the gland remains unclear. The possible role of the rostral gland of termites was discussed as an adaptation towards encounters with soil pathogens. In future, in vivo studies will serve to uncover the functions of these unique structures to learn more about the adaptation of termites to their living conditions.

The ultrastructure of the rostral gland in soldiers of Verrucositermes tuberosus (Blattodea: Termitidae: Nasutitermitinae)
Cedric Aumont, T. Beránková, Dino McMahon, R. Radek, P. D. Akama, D. Sillam-Dussès, J. Sobotnik
published in Arthropod Structure & Development, volume, 73 page 101238
BAM Materials and the Environment