Ageing and somatic maintenance in social insects

- Social insect shows great intraspecific disparity of lifespan among castes.
- Senescence is widely believed to be the result of accumulating somatic damage.
- Longer-lived castes should therefore show lower damage and higher somatic maintenance.
- Studies so far do not show strong support for these predictions.
- How social insects could be used to test other theories of ageing is considered.

Social insects offer exciting prospects for ageing research due to the striking differences in lifespan among castes, with queens living up to an order of magnitude longer than workers. A popular theory is that senescence is primarily the result of an accumulation of somatic damage with age, balanced by investment into processes of somatic maintenance. Investigation of these predictions in social insects has produced mixed results: neither damage accumulation nor investment into somatic maintenance is consistently different between castes with different lifespans. We discuss some limitations of the studies conducted thus far and consider an alternative proximate theory of ageing that has been recently proposed.