Fig. 5

Evolution of the average direct and maternal genetic parameters of queens under mass or within-maternal line selection with a monoandrous or polyandrous mating system. The evolution of the mean direct (a) genetic variance for the four scenarios of setup 1 is very similar to that of the mean maternal (b) genetic variance. Two significant decreases in variance take place between years 1 and 2 (first selection) and between years 4 and 5 (first selection in the closed population). Until year 4, the loss in direct and maternal genetic variance is essentially due to the Bulmer effect, whereas loss continues subsequently as inbreeding increases. Within-maternal line selection with polyandrous mating maintains the highest genetic variance, whereas mass selection with monoandrous mating induces the most severe losses. The within-maternal line selection with monoandry and mass selection with polyandry scenarios produced similar intermediate losses