Table 1 The qualitatively different behavioural responses (parameterization and associated vector behaviours) described by the new formula
Response Type | Ecological equivalent | Parametric conditions | Vector behaviour |
|---|---|---|---|
Type I | Holling’s Type I | α = 1 β = 1 | Indiscriminate, or vector biting that is consistent (proportionate) across relative availabilities of alternative hosts |
Type II | Holling’s Type II | α < 1 β ≥ 1 | An anthropophilic vector which takes most of its blood meals on humans even when humans are less available than other hosts, and when humans and non-humans are equally available, almost all blood meals are taken from humans |
Type III | Holling’s Type III | α ≥ 1 β > 1 | This is the pattern expected with a learned behaviour, such that female mosquitoes learn to prefer the more common Type of host |
Type IV | Inversion of Holling’s Type II | α > 1 β ≤ 1 | A zoophilic vector is disinclined to bite humans until they constitute all but the only available blood source |
Type V | Inversion of Holling’s Type III | α ≤ 1 β < 1 | HBI saturates and becomes relatively invariant when humans and non-humans are at similar availability. This is analogous to ‘negative prey switching’ whereby the ‘predator’ consumes disproportionately less of the more available ‘prey’ [45]. Eventually, when non-humans become vanishingly rare, the HBI is forced to increase sharply to unity |