Poles Apart: Comparing Trends of Alien Hymenoptera in New Zealand with Europe (DAISIE)

Abstract

Developing generalisations of invasive species is an important part of invasion biology. However, trends and generalisations from one part of the world may not necessarily hold elsewhere. We present the first inventory and analysis of all Hymenoptera alien to New Zealand, and compare patterns from New Zealand with those previously published from Europe (DAISIE). Between the two regions there was broad correlation between families with the highest number of alien species (Braconidae, Encyrtidae, Pteromalidae, Eulophidae, Formicidae, Aphelinidae). However, major differences also existed. The number of species alien to New Zealand is higher than for Europe (334 vs 286), and major differences include: i) the much lower proportion of intentionally released species in New Zealand (21% vs 63% in Europe); and ii) the greater proportion of unintentionally introduced parasitoids in New Zealand (71.2% vs 22.6%). The disharmonic ‘island’ nature of New Zealand is shown, as a high proportion of families (36%) have no native representatives, and alien species also represent >10% of the native fauna for many other families. A much larger proportion of alien species are found in urban areas in New Zealand (60%) compared to Europe (~30%), and higher numbers of alien species were present earlier in New Zealand (especially <1950). Differences in the origins of alien species were also apparent. Unlike Europe, the New Zealand data reveals a change in the origins of alien species over time, with an increasing dominance of alien species from Australasia (a regional neighbour) during the past 25 years. We recommend that further effort be made towards the formation, and analysis, of regional inventories of alien species. This will allow a wider range of taxa and regions to be examined for generalisations, and help assess and prioritise the risk posed by certain taxa towards the economy or environment.

Potential for biological control of the vegetable leafminer, Liriomyza sativae (Diptera: Agromyzidae), in Australia with parasitoid wasps

“…Hernández et al (2009Hernández et al ( , 2011 found it to be the most abundant parasitoid reared from L. trifolii infesting peppers in Texas. In New Zealand, N. formosa was recorded in 1989 as an unintentional introduction (Ward & Edney-Browne 2015), but its current status is unclear. The species has not been formally identified in Australia, although Neochrysocharis specimens have often only been identified to genus (Bjorksten et al 2005;Lambkin et al 2008) and warrant further investigation.…”

Dataset of host records for introduced parasitoid wasp species (Hymenoptera) in New Zealand

“…The introduction of species to new regions is occurring at an increasing rate globally (Seebens et al 2018). This includes species that are deliberately introduced for the purposes of biological control of pests or of species that are accidentally introduced through human-mediated transport networks.…”

“…A dataset, derived from records of parasitoids reared from field-collected hosts, would contribute to validating the host range hypotheses generated in the lab studies, facilitating better understanding of actual or ecological host range (Paynter and Teulon 2019). Molecular approaches also offer a new technique to inform about parasitoid-host associations (Rougerie et al 2010;Gariepy et al 2018).…”

“…Many species of Hymenoptera are well known as invasive species, for example, ants and social wasps ( Lester and Beggs 2019 ); whereas parasitoid Hymenoptera have received less attention despite being widely introduced ( Rasplus et al 2010 ; Ward and Edney-Browne 2015 ). A fundamental part of assessing the risk of parasitoid wasps towards native or non-target species is understanding their host associations.…”

The Diversity and Impacts of Alien Species

“…Acknowledging the diffi culties of determining the full range and extent of environmental damage and native species extinctions fl owing from invasive alien species, Pimentel et al ( 2005 ) also noted that about 400 of the 958 species (all taxa combined) then listed as threatened or endangered under the United States Endangered Species Act were so primarily because of competitive or predation impacts of alien species. Similar, (Ward and Edney-Browne 2015 ) 2.1 Introduction: The Diversity of Alien Species if less severe or less obvious, impacts must extend to numerous non-listed taxa. Pimentel et al ( 2005 ) also emphasised the distinction between plant and vertebrate introductions (most of which have been intentional) and invertebrate introductions (most of which have been accidental or unplanned).…”