Constant release strategy

A release strategy where the same number of Wolbachiainfected mosquitoes are released at every release event for the duration of the IIT programme. This strategy does not use population monitoring to alter the number of individuals released. The number of Wolbachiainfected mosquitoes released per event is equal to the overflooding ratio multiplied by the male population at the commencement of the IIT programme.

Adaptive release strategy

A release strategy where the population size is assumed to be known at each release event. The number of Wolbachiainfected individuals released per event is equal to the overflooding ratio multiplied by the current male population.

Crude adaptive release strategy

A release strategy where releases are identical to the constant release strategy, but in three phases. In the first phase, the number of Wolbachiainfected mosquitoes released per release event is equal to the overflooding ratio multiplied by the male population at the commencement of the IIT programme. The second phase begins once the population reaches 50% of its initial size, at which point, the numbers of mosquitoes released per event is halved. Phase 3 begins when the population reaches 10% of its initial size, at the numbers released per event are reduced to 10% of that used in the first phase.

Eliminated

A wildtype population is considered to have been eliminated when there are no wildtype individuals alive in any of the life stages present in the model (i.e. no adults or future adults) at the end of the simulation.

Established

A Wolbachia population is (conservatively) defined to be established if the proportion of adults in the population that are infected with Wolbachia at the end of the simulation is greater than 20%.

Female contamination probability (FCP)

The probability that each mosquito released into a population at a release event is a female. The release of females may occur due to errors in the sex separation process and are modelled as events that follow independent, Bernoullidistributed random variables for each individual.

Future adults

An abstract pool of individuals used in the model to represent nonadult life forms that will, with certainty, survive to become adults. See Additional File B: B2.1B2.3 for further details.

IIT endpoint

The final state of a population that has been subjected to a WolbachiaIIT programme. There are four possible endpoints: (i) elimination of the wildtype mosquito population, (ii) establishment of Wolbachia into the population, (iii) indeterminate Wolbachia negative and (iv) indeterminate Wolbachia positive. These four outcomes are defined in greater detail below.

Indeterminate Wolbachia positive

A population is considered to have reached an IIT endpoint of indeterminate Wolbachia positive if it is neither eliminated nor established, but where there are one or more individuals in one of the life stages (i.e. adults or future adults) that are infected with Wolbachia at the end of the simulation (i.e. 365 days postfinal release).

Indeterminate Wolbachia negative

A population is considered to have reached an IIT endpoint of indeterminate Wolbachia negative if it is neither eliminated nor established and there are no individuals of any life stages (i.e. no adults or future adults) that are infected with Wolbachia at the end of the simulation (i.e. 365 days postfinal release).

Overflooding ratio

The number of Wolbachia males released into the population at each release event divided by some baseline population (e.g. the initial wildtype male population size).

Unstable equilibrium threshold (UET)

The frequency of Wolbachia infection in a mosquito population above which a particular strain is likely to spread [15].

Wildtype population

A population consisting entirely of individuals that are not infected with Wolbachia.
