Effect of odour on prey pattern aversion in jumping spiders

Many animals defend themselves with toxic chemicals and use multimodal warning displays involving odours and bright colours to advertise their toxicity. Yet, how coloration and odour interact and why they so often evolve together is not well understood. Recent work in jumping spiders has shown that defensive odours from three chemically defended bugs (Order Hemiptera: Acanthocephala femorata, Mormidea sp. and Leptoglossus phyllopus) increase a foraging aversion to red prey. Here, we ask whether these odours also increase avoidance of another visual warning: high-contrast stripes. Jumping spiders (Habronattus trimaculatus) were given choices between pattern-manipulated termites (solid white and black-and-white striped) in the presence or absence of a defensive odour from one of the aforementioned bug species. We predicted that any aversion to stripes would be stronger when odour was present. Surprisingly, we found no effect of any bug odour on the spiders’ aversions to stripes. Interestingly, these odours that so strongly and consistently trigger aversion to red do not have the same effect on stripes. This highlights the different ways that odours and coloration can interact (or not) to influence predators, providing insight into the diversity of aposematic displays in nature.