Experimental and comparative analysis of masquerade in flea beetles (Coleoptera: Chrysomelidae)

Prey animals employ masquerade to avoid recognition by visual predators by developing a resemblance to inedible objects in their environment. Phytophagous flea beetles seem to resemble models of their own manufacture. While feeding they cause light- or dark-coloured hole-like damage on the leaves of their host plants that resembles the beetle's body in colour and size. Resemblance to the model and the frequency of the model can influence the efficiency of masquerade. To examine masquerade efficiency in light- and dark-coloured beetles, we evaluated their survival benefits from resembling feeding damage in the field. This was done by using two species of beetle of different colour as prey and a jumping spider as the predator. Dark-coloured species were more likely to avoid predation when they were placed on a background with damage similar in colour to their body, whereas increased survival was not recorded for light-coloured species. The extent of the feeding damage of 34 light- and dark-coloured species of beetle was compared. Variation in the extent of the damage was associated more with host plant taxa than beetle body colour. These results indicate that the efficiency of masquerade can vary among beetle species and/or phenotypes.