Life and Death of Termite Colonies, a Decades-Long Age Demography Perspective

Abstract

A eusocial insect colony represents a complex biological entity that must ensure degrees of perennity once it reaches maturity (production of dispersing imagoes over many successive years) to optimize its reproductive success. It is known that a subterranean termite colony invests differentially in different castes over time and adjusts colony functions depending on colony internal and external conditions over many years of activity. However, the current study demonstrates that Coptotermes formosanus Shiraki field mature colonies go through dramatic demographic changes and breeding structure shifts, even many years after they have reached reproductive success. By analyzing the changes in age demography of C. formosanus colonies from four field sites, we here provide a new perspective on how a colony may function over decades, which reveals that each colony demographic trajectory is unique. In a way, throughout its life, a termite colony displays its own “demographic individuality” that drives its growth, its foraging ability, its competitiveness, its age demography, its senescence and ultimately its death. This study is therefore a narrated story of the life -and death- of different C. formosanus field colonies over decades of observation.

Eusociality and the transition from biparental to alloparental care in termites

“…These results indicate that there is a sensitive time frame between ~75 and ~150 days where the two parents progressively cease to provide biparental care, not because they no longer have to provide, but because they can no longer provide, owing to their depleted nutritional reserves. In fact, this study shows that the Coptotermes queen and king combined biparental care can only support the development for ~15 workers on average, while subsequently produced individuals progressively developed through alloparental care, as the colony entered ergonomic growth (Chouvenc et al, 2022; Oster & Wilson, 1978).…”

“…This metabolic shift directly reflects that both the queen and king stopped being involved in any brood care activities and solely focused on reproduction where a requirement for nitrogen may become more demanding (Mullins et al, 2021; Tong et al, 2021). Queens would later initiate ovarian expansion towards physogastry (Chouvenc & Su, 2014), as individual queens wet weight increases from ~7 to ~70 mg within 4 years of colony growth (Chouvenc, 2018), towards colony maturity and perennial dispersal flights events (Chouvenc et al, 2022).…”

Elimination of structural and tree infestations of the Asian subterranean termite, Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) with noviflumuron baits in above-ground stations

“…In our study, IG stations were placed in the vicinity of infested trees and structures, yet none of the IG stations were intercepted by C. gestroi that is supposed to thoroughly search for food in the immediate area by constructing a highly branched tunnel network. In many of our previous studies with C. formosanus , wooden stake or IG stations placed in the vicinity of infested wood, trees, or structures were immediately intercepted and used for activity monitoring for many years (Su and Scheffrahn 1988, Su 1994, Chouvenc et al 2022).…”

Regulation of soldier caste differentiation by microRNAs in Formosan subterranean termite (Coptotermes formosanus Shiraki)

“…Termites ( C. formosanus ) were collected using a termite ground trap in Shangchong Fruit Tree Park, Guangzhou, China ( Su & Scheffrahn, 1986 ; Chouvenc, Ban & Su, 2022 ). Only workers and soldiers were collected with the trap.…”