Sticky leaves are a red flag for things like scale or mealybug, Carojsmit. Unfortunately, most ferns, including Humata species, are sensitive to insecticides, or even soap sprays. The remaining treatment is to paint each individual clump of mealybugs, or scale insect, with rubbing alcohol on a Q-tip, or a small artist's brush. That will leave a tiny brown mark on the leaf, or leaf stem, but won't kill entire leaves, like spraying would. It could take some time to clean the whole plant up.

Thank you so very much!!!

Your welcome!