Phototaxic Behaviour of Flies with and without an ectoparasitic mite

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.

首先，我们通过微 arena 实验（micro-arena experiment）证实，相较于黑暗环境，果蝇在光照环境中感染螨类的概率更低。在基线条件（无螨环境）下，未交配雌果蝇与已交配雌果蝇在趋光箱（phototaxis chamber）的黑暗侧停留的时长显著更长。雄果蝇未表现出显著的正向或负向趋光性。与之相反，当暴露于螨类环境时，未交配与已交配雌果蝇均未表现出显著的趋光性。当受到螨类威胁时，果蝇的负向趋光性减弱，这表明趋光性是一种行为免疫机制。