First, we demonstrated that flies are less likely to be infected by mites when exposed in light environments than dark environments using micro-arena experiments. In baseline conditions (mite-free environments), unmated female flies and mated female flies spent significantly more time in the dark side of the phototaxis chambers. Males did not show significant negative or positive phototaxis. Contrarily, when exposed to mites, neither unmated or mated females displayed significant phototaxis. Flies became less negatively phototaxic when threatened with mites, suggesting phototaxis is a mechanism of behavioural immunity.

Phototaxis experiments were conducted in phototaxis chambers. Flies were observed and if they were on the light or dark side of the chamber was recorded at each minute interval. Female flies were either exposed to mites or alone in the phototaxis chamber. We also tested the impact of mating status on female phototaxis (and the mating-status, exposure interaction). The phototaxis behaviour of Male flies unexposed to mites was also measured.

Additional experiments followed females in a phototaxis chamber with a single mite. Either 1) a mated female and 1 mite or 2) an unmated female and 1 mite. The location of both the fly and mite were recorded at each interval.

Experiments are described in full (in review).

Flies.csv description

The goal of this experiment was to test if flies changed their phototaxis behaviour (% time in light) in response to the presence of mites (in a previous experiment we found flies are more vulnerable to infection in the dark). Each fly was also assigned a unique ID.

Each fly was observed for N number of observations (Nobs, 1 minute apart), and the number of observations at which they were in the dark was recorded (Ndark). PropDark = Ndark/Nobs.

Female flies were either mated (M), unmated (U). Females were also either exposed to mites (E) or not exposed to mites (N).

Male flies not exposed to mites were also observed.

Fly Variable Names/codes

Group: Flies were unmated females unexposed to mites (UnmatedFUnexposed), mated females unexposed to mites (MatedFUnexposed), Male flies unexposed to mites (MaleUnexposed), Mated females exposed to mites (MatedFExposed), or unmated females exposed to mites (UnMatedFExposed).

FlyID: a unique identify for each fly

Sex: fly sex (male/female)

Mating status: mating status of female flies (Mated=M, Unmated=U), male mating status was not considered (NA).

Nobs: number of observations for a fly

NDark: the number of observations at which a fly was in the dark side of the phototaxic chamber

PropDark: NDark/NObs

Mites.csv description

We also recorded the position of the mites in the mites. Mites were either in a chamber alone (solo), with a mated female fly (WithMated), or with an unmated female fly (WithUnmated). The ID of the fly paired with the mite is listed when applicable (see flies.csv).

Each mite was observed for N number of observations (Nobs, 1 minute apart), and the number of observations at which they were in the dark was recorded (Ndark). PropDark = Ndark/Nobs.

Mite Variable Names/codes

Group: Mites were either in chambers alone (solo), in a chamber with a mated female fly (WithMated), or in a chamber with an umated female fly (WithUnmated)

MiteCode: A unique code for each mite

Paired.fly: the fly the mite was with in the WithMated and WithUnmated condition, NA when the mite was alone (as in the Solo group)

Nobs: number of observations for a mite

NDark: the number of observations at which a mite was in the dark side of the phototaxic chamber

PropDark: NDark/NObs