gastheerplant

A gastheerplant is a plant that serves as a host for a dependent organism, providing food or habitat. The term is commonly used in ecology and agriculture to describe plants that support herbivorous insects during their larval stage, as well as hosts for parasites, parasitoids, or parasitic plants. The host-plant relationship is central to many ecological interactions and to pest management.

The degree of host specificity varies. Monophagous species feed on a single plant species, oligophagous on a few related species, and polyphagous on many. Host plants can supply resources beyond food, such as oviposition sites, shelter, or nectar for adult parasitoids. Some plants act as hosts to parasitic plants like mistletoes, which depend on a host plant for water and nutrients.

Examples illustrate the concept. The monarch butterfly lays eggs on milkweed (Asclepias); monarch caterpillars feed exclusively on milkweed. Other butterflies and moths are specialized on nettles, willows, or oaks. In agriculture, identifying host plants helps design integrated pest management strategies by predicting pest outbreaks and selecting resistant or trap crops.

Studying host-plant associations involves field observations, rearing experiments, and literature. Loss of host plants due to land-use change can threaten specialist species; restoration often focuses on planting known host species to support pollinators and herbivores.