A model of infection in honeybee colonies with social immunity
Fig 2
Role of the hygienic behavior (krem).
A: Healthy brood and nurses in a colony with the hygienic behavior are maintained against an infection. The simulation is based on Eqs 1–4 with model parameters listed in Table 1 with l0 = 120 and krem = 2.5 × 10−3. We treat pt1 ⋅ kRN ⋅ iR1 as a parameter, which is equal to 5 × 10−4. The infection is introduced (pt1 ⋅ kRN ⋅ iR1 = 5 × 10−4) at day 20 (vertical purple line). B: All brood and nurses in a colony without the hygienic behavior become infected. The simulation setting is the same as in panel A, except that krem = 0. C: The steady-state number of healthy nurses is plotted as krem is varied while other parameters are fixed. Bold lines represent a stable steady-state and a thin line represents an unstable steady-state. D: The 2-parameter bifurcation diagram is plotted as both krem and pt0 are varied. The diagram is divided into three regions depending on the state of the colony (healthy, bistable, and infected).