Patch leaving strategies and superparasitism: an asymmmetric generalized war of attrition
When several competitors deplete a patch, it can be advantageous for each of
them to stay provided that others leave, whereas, on the other hand, staying
longer decreases the expected payoff for everyone. This situation can be
considered as a generalized war of attrition. Previous studies showed that
when competitors interfere optimal patch leaving strategies become
stochastic and the expected leaving time is much larger than predicted by
the marginal value theorem.
The possibility of superparasitism, as occurs e.g. in parasitoids,
induces such interference. In addition, it gives several complications.
First, the payoff of females that have left the patch is affected by the
ovipositions of the remaining individuals. Second, differences in arrival
time of females cause payoff-relevant asymmetries, since females that
arrived early have parasitised more hosts in a patch at the moment
superparasitism starts than those that arrived late.
We show that this can be modelled as an asymmetric generalized war of
attrition, and derive global characteristics of the ESS for simultaneous
decisions when to start superparasitism and when to leave a patch.