The Significance of Alien Species to Insect Conservation

Abstract

The pursuit of insect conservation is founded in informed management of species, assemblages and their functional environments to sustain them in the face of increasing variety of imposed changes, stresses and threats. Anthropogenic changes to natural environments are perhaps most severe in intensive processes related to the large areas subsumed by urbanisation and related industrialisation, agriculture and commercial forestry, in all of which land cover is changed fundamentally from its original condition. Those changes continue to expand and to progressively infl ict dramatic alterations on natural areas, notably of native vegetation, wetlands and freshwater bodies. Many sensitive ecological communities, many of them unique or highly restricted in extent, have been lost, together with the plants and animals they previously harboured.Direct destruction of natural and semi-natural areas, broadly 'habitat loss', is the most universal of a panoply of threatening processes associated with losses of biodiversity, with impacts that span the entire variety of Earth's biological heritage. Many factors contribute to increased endangerment of insect species -and, in most contexts in which the habitat or biotope is not clearly lost, the relative importance and impacts of these factors remain largely conjectural. Linked intricately with habitat changes, and major contributors to changes in native biodiversity, the advent and impacts of alien species -newcomers to their receptor environments -are also universal, with potential to markedly confound other habitat changes through imposing a range of novel ecological stresses and interactions. They are thus major concerns in conservation management, with the taxa of concern spanning all major taxonomic groups. Most alien species considered are plants, arthropods or vertebrates, but Wagner and Van Driesche ( 2010 ) also included invasive pathogens and detritivores in their review of impacts and drawing largely from North American contexts.