Influência da visão de cores e da formação de imagem de busca na detecção de insetos por humanos

Abstract

Insects are an abundant group and are part of the diet of many predators. To avoid them, some insects use colors to blend into the environment, while others use consipicuous colors to signal that they are unpalatable. The use of colors by insects can help them survive, but the predator's color vision can break the camouflage. Here, we investigate the visual phenotype of the predator, the type of coloration, and the size of the insect. Based on this, our research aims to determine among dichromatic and trichromatic humans who has the advantage in detecting insects. These insects use different colorations, such as disruptive coloration, aposematic coloration, and background matching. We also verify if the target size (large and small) influences detection. To do this, we prepared and edited photos of insects on the Trilha dos Saguis at UFRN and selected 40 participants, consisting of 20 trichromats and 20 dichromats. The participants touched a touchscreen monitor, choosing one photo out of four, where only one had the positive stimulus (photo containing the insect) and three had negative stimuli (photos containing the landscape without the insect). Our results indicate that in terms of response latency of the targets, trichromats are faster in detecting insects when they present aposematic coloration, background matching, and when the targets are smaller. In the case of disruptive coloration and when the targets are large, there is no significant difference between dichromats and trichromats. Regarding the response accuracy, dichromats detect more insects, especially when they have background matching coloration and when the targets are small, compared to trichromats. For disruptive and aposematic coloration, trichromats performed better than expected compared to dichromats. Our results indicate that trichromats are faster and detect more aposematic and disruptively colored insects because these conspicuous colors are efficient against dichromatic predators, but trichromacy favors the predator in detecting these targets. Dichromats detect more targets, especially when they are small and have background matching coloration, due to chromatic noise, which affects trichromats more since they better distinguish colors. However, this energy used to distinguish colors hinders the identification of achromatic cues, unlike dichromats who can redirect this energy and use it to identify achromatic cues, favoring a better assessment of shapes, contours, and textures