CV and colony data vespid mandible wear

Key structures of insects, such as their mandibles, become worn by the use
and this leads to performance constraints, increase of metabolic costs,
and decrease of individual’ both lifespan and survival. Studying this
phenomenon is interesting in species that build nests as it demands a
significant amount of mandible labor; however, the effect of this
selective factor is less obvious in species like social vespids that
perform different tasks at different ages. By comparing mandible wear
between individuals of different ages in 18 colonies of 13 species of
neotropical social wasps (Vespidae: Polistinae), we aimed to understand
(1) the distribution of mandible wear across ages, and (2) the association
between colony size and the coefficient of variation of mandible wear as
an indicator of specialization. Despite a general positive trend between
mandible wear and age, there are numerous exceptions and no age seems to
concentrate this phenomenon. Mandible wear variation was evenly
distributed throughout the worker ages, and was not correlated with colony
size. Our study suggests that individuals distribute mandible demanding
tasks throughout their life to reduce structural attrition which may
improve worker’s general output. We proposed that, to extend both life
expectancy and general performance of the workers, wasps may spread the
more demanding tasks over longer and less intense periods.