Thanks for sending the image. The dark spots on the leaves is not a boring insect but instead a fungal infection. You need to cut back all the old foliage now and leave just the blooming stems. The fungal infection will overwinter and infect more of your plants and even the flower petals if you do not remove those leaves. In early winter like December I force myself to get outside and get snippy with all my hellebores leaving just the tight stems and buds. Then in early spring when the hellebores flower there are no leaves to hide the blooms and this foliage cleanup also keeps the plants healthy.  You can help to avoid this fungus among us by improving air circulation by not crowding the plants and try not to wet the leaves if you water. Keep growing, Marianne Binetti