Conclusion
The combination of major dietary shifts driven by non-native taxa and
the high prevalence of parasite reads from spiders in ginger sites,
gives support to the idea that heavily invaded habitat could function as
a sink, rather than a source, environment for endemic taxa. Because
spider diets tend to reflect not only the diversity of insect prey in a
given habitat but also the choice of the spider (Cuff et al.2021), the spiders are showing not only how the arthropod composition
changes with ginger invasion, but also how spiders are responding to
environmental shifts. The high density of non-native taxa and the
increases in both parasitoid wasps and entomopathogenic fungi clearly
demonstrates that the sites modified by plant invasion are associated
with a transformation of the arthropod community. The importance of this
work is in highlighting how entire communities, and the associated
interactions, are modified by a single invasive species. These
introduced species do not function as reservoirs – or “safe havens”
– for native taxa. Rather, they may act as “sinks”, drawing native
taxa into the transformed environment lacking native prey and exposing
species to higher levels of parasitism. Cascading effects of ecosystem
alteration and the restructuring of biotic interactions may contribute
to extinction debt in invaded systems, where the full consequences of
invasion do not become evident for many years (Kuussaari et al.2009).