Fig 4. Schematic sketch of the number of successes s that a WF wasp is expected to complete when the common stomach water level is w (solid curve).

An upper bound to s is the number of successes S that a WF wasp needs to completely rid its load (dashed curve). There exists a water level at which a WF wasp is expected to make a maximum number of successes max(s). The plot for the number of successes s_p expected for a PF wasp at common stomach water level w is obtained by s_p(w) = s(1 − w). These curves are meant to convey only a general trend (described in Section 2.1) and are not plots of equations.