Expansion of the nest ofNasutitermes costalis

Abstract

The nest expansion behavior ofNasutitermes costalis, a common Neotropical arboreal termite, was analyzed by means of direct and photographic observation of a thriving laboratory colony over a 45-month period. 52 expansion episodes were recorded, each resulting in the addition of as much as 10% to the nest volume. The expansion process can be divided into 3 phases Initiation, Building, and Termination. Termination results in a nest surface whose shape focuses initial building efforts during the Initiation of subsequent expansion. Building consists almost entirely of multiple repetitions of a few simple architectural elements — primarily the branching of one wall into two and the joining of neighboring walls via a bridge — all occurring on a smooth “active surface” which persist throughout each expansion episode. Interesting similarities between certainN. costalis nest expansion architectural features and structures builtde novo by queened termite groups from 3 subfamilies of the Termitidae suggest that this is a relatively primitive mode of nest expansion.