Alcea "Alcea" species are used as food plants by the larvae of some Lepidoptera species including "Bucculatrix quadrigemina" and "Vanessa cardui", the painted lady. The mallow flea beetle ("Podagrica fuscicornis") is a pest that makes tiny holes in the leaves. Cutworms, aphids, and capsid bugs use the plant as a food source in hotter and drier conditions. A number of weevils use "A. rosea" as their host plant, including "Rhopalapion longirostre", "Alocentron curvirostre", and "Aspidapion validum". The plants are also susceptible to the pathogenic fungus "Puccinia malvacearum", the hollyhock rust. A hollyhock flower, known in Japan as , was incorporated into
Clonostachys rosea f. rosea penetrate, and grow inside the hyphae and conidia of "B. cinerea". Nematodes are infected by "C. rosea" when the fungus' conidia attach to their cuticle and germinate, going on to produce germ tubes which penetrate the host's body and kill it. In 2008 an isolate of "Clonostachys rosea" (NRRL 50072) was identified as producing a series of volatile compounds that are similar to some existing fuels. However, the taxonomy of this isolate was later revised to "Ascocoryne sarcoides". Clonostachys rosea f. rosea Clonostachys rosea f. rosea, also known as Gliocladium roseum, is a species of fungus in the family Bionectriaceae.