Why and how do termite kings and queens live so long?

Abstract

Lifespan varies greatly across the tree of life. Of the various explanations for this phenomenon, those that involve trade-offs between reproduction and longevity have gained considerable support. There is an important exception: social insect reproductives (queens and in termites, also kings) exhibit both high reproductive outputs and extraordinarily long lives. As both the ultimate and proximate mechanisms underlying the absence of the fecundity/longevity trade-off could shed light on the unexpected dynamics and molecular mechanisms of extended longevity, reproductives of social insects have attracted much attention in the field of ageing research. Here, we highlight current ecological and physiological studies on ageing and discuss the various possible evolutionary and molecular explanations of the extended lifespans of termite reproductives. We integrate these findings into a coherent framework revealing the evolution of longevity in these reproductives. Studies on termites may explain why and how ageing is shaped by natural selection. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’

Ageing and sociality: why, when and how does sociality change ageing patterns?

“…Tasaki et al [31] summarize what is known about the mechanisms of ageing and longevity in termites, from transposable elements to the breast cancer susceptibility gene BRCA1. They also focus on oxidative stress, but as in [30] the results are inconclusive, with apparently species-specific peculiarities.…”

Seasonal movement of royal chambers: where are the kings and queens of temperate termites in winter?

“…This study reports the first evidence that termite colonies provide kings and queens with underground winter royal chambers to avoid encountering potentially lethal temperatures. The survival of royals (especially the primary king in R. speratus ) is critical to ensure the maintenance of their colony [26,27], and termite societies are selected to protect their kings and queens from extrinsic mortality [13,14,40]. Social insects collectively construct a variety of nest structures through local interactions among individuals [41–43].…”

“…Societies of social insects protect their kings and queens from predators as well as harsh environments [13,14]. Termites are generally found in tropical regions as the temperate zone is their latitudinal limit of distribution [17][18][19][20].…”

“…Therefore, the survival of reproductives is crucial for termites to maintain a thriving society. Kings and queens are generally protected by social-level defenses provided by non-reproductives, which greatly reduces the risk of extrinsic mortality by predation, disease, starvation, desiccation, and extreme temperatures [13,14]. The elaborate nest structure is one of the most essential components of their social defense, and enables them to expand habitats by insulating extreme temperatures creating favorable microenvironments [15,16].…”

Genome‐wide profiling and identification of insulin signaling pathway genes of subterranean termite castes

“…A single colony of termites consists of various castes, including queen, king, soldiers, and workers (Jemielity et al 2005); among these castes, the reproductive castes of termites live for 18 to 30 years and the sterile worker/caste for a few days to months (Haroon et al 2020). The ultimate and proximate mechanisms underlying this unique feature could illustrate the unexpected molecular dynamics and long-living mechanisms (Tasaki et al 2021). Understanding of evolutionary criteria for high longevity in social insects is vital because of (i) the most extensive group with 7.5 × 10 5 identified moieties having 5 × 10 5 life cycles (Southon et al 2015), (ii) to determine the co-evolutionary relationship between longevity and social insects (Jemielity et al 2005).…”