No benefit in diversity? The effect of genetic variation on survival and disease resistance in a polygynous social insect

摘要: Multiple mating by queens has been shown to enhance disease resistance in insect societies, because higher genetic diversity among nestmates improves collective immune defences or offers a certain level of herd immunity. However, it remained ambiguous whether polygynous societies with large numbers also benefit from increased diversity. 2. We used one the very few ant species that can be reared across generations, pharaoh ant, Monomorium pharaonis Linnaeus, create experimental colonies two types enhanced diversity: (i) mixed workers three divergent inbred lineages representing 'polygyny-equivalent' multiple (i.e. between-worker variation); and (ii) uniform whose overall heterozygosity was subsequent generations crossing between same within-worker variation). 3. found significant differences worker survival lineages, exposure conidiospores fungal pathogen Beauveria bassiana causing mortality independently their type. Increased did not improve Beauveria. 4. Enhanced had rates similar most resistant lineage, whereas lower larval survival. Workers show any infection- avoidance behaviour. 5. Average appeared unaffected presence conidiospores. It benefitted but reduced independent infection. This suggests negative, cryptic social interactions may affect 6. The present results do provide evidence for against link variation ants, differ considerably general Thus, increasing advantages face exposure, polygyny polyandry directly comparable mechanisms creating adaptive towards pathogens.