The Ecological and Evolutionary Consequences of Alien Invasive Species

Abstract

Invasive species have almost innumerable potential interactions with native biodiversity, and these include potential to reduce local distinctiveness of biota at three main levels. Of these, the taxonomic level of change is that most frequently noted, as local endemic species decline or are lost and replaced by invasive species. They are followed by functional changes flowing from changed assemblages and novel interactions. Least heeded, but likely to be widespread, genetic distinctiveness and impoverishment must also be included. For understanding the last theme, and in contexts such as seeking natural enemies for biological control (p. xx), tracing origins of invasive stocks by genetic characterisation is increasingly relevant, with a comment that `novel molecular techniques are under-utilised in studies of invertebrate pest invasions' (Cesari et al. 2015) exemplified by analyses of the Brown marmorated stink bug (Halyomorpha halys, Pentatomidae). Those investigated showed that two different populations were present in Europe, and that recent invasions to Italy occurred through two different pathways.