In this image, panels A and B show western tarnished plant bugs (Lygus hesperus). Panels C and D show convergent lady beetles (Hippodamia convergens). The insects in the top row of each panel were marked with a fluorescent dye called SmartWater; the insects in the bottom row of each panel were control specimens “marked” with water. The two photos on the left (A and C) were photographed with white light; the two photos on the right (B and D) were photographed with UV light. Note in the UV photos that the SmartWater-marked individuals showed green fluorescence, whereas the control individuals did not. (Image originally published in Hagler et al 2021, Journal of Insect Science)