Are there other insects that eat mint leaves?
There is another beetle native to Britain, known as the green mint beetle, Chrysolina herbacea. This is 8-9mm in length and is a shiny emerald green. The black larvae are similar to those of the blue mint beetle. Pale green caterpillars of several moths, Pyrausta spp., are also found on mint; they loosely spin together foliage at the shoot tips with silk threads and eat the leaves. Some other species of moth caterpillar and slugs and snails also sometimes eat mint leaves.