Data from: The adaptive function of waste management in a social spider mite

Effective waste management is fundamental to the success of social living,
playing a key role in disease prevention and maintaining a habitable
environment. However, experimental evidence for its adaptive significance
remains limited, primarily due to the difficulties in manipulating
defecation behaviour. The social spider mite Stigmaeopsis longus defecates
cooperatively near nest entrances, guided by tactile and chemical cues. We
experimentally altered the number and location of defecation sites using
host plant extracts that mimic the chemical cues and examined the effects
on reproduction and survival under different female densities. Centralised
and increased defecation sites reduced egg survival in high-density nests,
but not in low-density ones. Nevertheless, both densities exhibited
increased nest extension, suggesting a compensatory response. When nest
extension was physically prevented, egg survival declined even in
low-density nests, confirming that nest extension mitigates the faecal
hazards. These findings demonstrate that spatial control of waste is
crucial for supporting group living by reducing exposure to faecal
hazards, particularly for immobile life stages such as eggs. This study
provides the first empirical evidence for the adaptive function of waste
management in spider mites, highlighting its potential role in the
evolution of sociality and nest-based living in arthropods.