Response of flower visitors to the morphology and color of crab spiders in a coastal environment of the Gulf of Mexico: supplementary material Rodríguez-MoralesDulce Ajuria-IbarraHelena Hernández-SalazarLaura T. Rico-GrayVíctor García-FrancoJosé G. RaoDinesh 2019 Predation is one of the main interactions between organisms and one of the primary selective agents for their survival. Both prey and predators have developed different strategies and characteristics that allow them to be conspicuous or go undetected. In sit and wait predators, their shape and appearance are important factors that allow them to remain undetected by their potential prey. Sit and wait predators such as crab spiders are difficult to identify when they sit on flowers or areas of flowers with colors similar to the color of their bodies. In this study, we aimed to determine if insects can recognize the morphology and color polymorphism of crab spiders by evaluating the response of flower visitors. We quantified the visits and approaches of floral visitors to the flowerheads of <i>Palafoxia lindenii</i> with spider morphology and color polymorphism treatments. Our results show that insects in general, and bees in particular, avoid visiting flowers with a real spider or a spider model and visit vacant flowers more frequently. In the case of the color polymorphism, insects approached flowerheads with spiders with a similar frequency independently of the color of the spiders, but did not visit them. Insects appeared to identify spiders through their morphological characteristics rather than their color characteristics, since flower visitors did not discriminate between the evaluated spider colors (white, lilac, and purple). This study emphasizes the differential response of different insect prey to the presence, color, and morphology of sit and wait predators.