Exotic herbivores on a shared native host: tissue quality after individual, simultaneous, and sequential attack.

摘要: Plants in nature are often attacked by multiple enemies whose effect on the plant cannot always be predicted based outcome of individual attacks. We investigated how two invasive herbivores, hemlock woolly adelgid (Adelges tsugae) (HWA) and elongate scale (Fiorinia externa) (EHS), alter host quality (measured as amino acid concentration composition) when feeding individually or jointly eastern (Tsuga canadensis), an important long-lived forest tree that is severe decline. The joint herbivore treatments included both simultaneous sequential infestations herbivores. expected resource depletion over time, particularly response to HWA. In contrast, HWA dramatically increased altered composition free acids. Compared control trees, total 330% after 1 year infestation. Conversely, EHS had a negligible individually. Interestingly, there was marginally significant × interaction suggests potential for presence reduce impact foliage species co-occur. suggest indirect effects water stress possible physiological mechanism our results. Understanding interactions change physiology shared crucial making more accurate predictions about mortality subsequent changes affected communities ecosystems, help design appropriate management plans.