Don’t eat me!: variation in warning signals in an Australian moth

Aposematism is an anti-predator strategy, using a conspicuous warning signal. Predators learn to avoid defended prey, and this incurs selective benefits to aposematic individuals. Variation is seen in most aposematic species, which does not fit with the current model of stabilising selection. This study explores contributions to variation in warning signals in an Australian moth genus, Amata. The Amata genus is a highly cryptic one, so DNA barcoding is used to identify freshly collected specimens using the CO1 gene and compared with species descriptions. Using collected specimens, variation in the warning signal was quantified, and then correlated with likely explanatory variables. Genetic barcoding confirmed two separate genera were collected from 11 locations in New South Wales; Amata and Eressa. From the genus Amata, two species were positively identified, as well as several individuals from the A. nigriceps spp. complex. Analyses on selected signal variables gave support to sexual selection as a possible explanation for warning signal variation. Contrary to predictions, variation was not explained by climate or the diversity of local bird predators. Future studies on this interesting Amata system could include specific predator responses to the warning signals, as well as more in-depth genetic work on the A. nigriceps complex.