Scarlet Lily Beetle - Identification

Identification

Lily beetles (Lilioceris lilii), belong to the Order Coleoptera, Family Chrysomelidae. In general, adult lily beetles are around 6 to 9 mm (¼–⅜ in) in length. The adult's elytra (harder forewings) are shiny and bright scarlet in colour. The lily beetle's underside, legs, eyes, antennae and head are all pitch black, greatly contrasting the bright red colour of the wings. They have large eyes, a slim thorax (neck) and a wide abdomen. Their antennae are made up of 11 segments. Furthermore, they have notched eyes and two apparent grooves on their thorax.

Lily beetles are often confused with the Cardinal beetles (Pyrochroa serraticornis) as they also have a black underside and wings that are spotless and red in colour. However, the lily leaf beetles have wing cases that are shinier with tiny dimples on them, they are more rounded in shape compared to the dull, narrow, flattened and elongated Cardinal beetle. Another difference between the two is their food preference. Lily leaf beetles are herbivores and are usually found on lily plants eating their leaves whereas the cardinal beetles are usually found on tree bark and flowers and feed on flying insects. Lastly, the cardinal beetle has a comb-like antennae.

Lily leaf beetles are fast fliers and hide very well. Additionally, when disturbed, they make a squeaky noise to deter predators. They could also be confused with unspotted ladybirds. Lily leaf beetles however are much slimmer than ladybirds.

Often the first thing that observers notice is lumps of sticky brown frass, with the larvae inside, on lily leaves, which should be immediately removed and destroyed.