DNA barcoding solves the mystery of the rainbow battleship caterpillar (Lepidoptera: Limacodidae) and reveals cryptic diversity in Australian slug moths

Despite their striking appearance and abundance, the diversity and life-histories of cup moths and their relatives (Lepidoptera: Limacodidae) in Australia are not well known. An example is a caterpillar commonly known as the rainbow battleship, or rainbow school bus. This caterpillar has been claimed to be the larva of Calcarifera ordinata (Butler, 1886), a wattle cup moth, but rearing experiments have recently shown that caterpillars of C. ordinata are not rainbow battleships. Here, we use DNA barcoding to identify the rainbow battleship by comparing the mitochondrial gene COI to sequences obtained from a DNA-barcoding blitz at the Australian National Insect Collection. We positively identify the rainbow battleship caterpillar as the larva of Comana albibasis (Walker, 1862), an association not previously hypothesised. The COI barcode region appears to be a useful tool for identifying limacodids, including matching larval and adult forms. Divergence within some currently recognised species highlights the presence of potentially undescribed species diversity in Limacodidae.