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Insect conservation is often impeded by a lack of species-specific data leading to difficulties in assessment of conservation and threat status. Utilising specimens and records held within natural history museums may help to overcome such limitations. We used specimens and their associated data from the New Zealand Arthropod Collection to provide a comparative analysis of threatened species and their related non-threatened congeners. A range of insect groups were covered, including families from the five mega-diverse insect orders. Data on the locality, date, habitat, and morphological measurements, were recorded for nearly 25,000 specimens from 460 species, of which 31 are Threatened and 104 are At Risk. Results found the Protected Area Network provided significantly less coverage for insect species classified as Threatened or At Risk. Body size, geographical distribution, and environmental variables were not consistent predictors of the current threat classification system. There were a disproportionately large number of At Risk species found on offshore islands. The current New Zealand threat classification system, based on trends in geographical occurrence and population sizes, does not accurately reflect the conservation needs of most insect species. This has significant implications for the utility of threat assessments for insect conservation.

Functional traits quantify the distinctiveness of ecological communities and provide a theoretical basis for understanding inter-specific competition, competitive exclusion, and limiting similarity. Functional traits can also be used to evaluate the risk of exotic species and biological control agents. The generalist parasitoid Meteorus pulchricornis (Wesmael 1835) (Braconidae: Hymenoptera) was used as a case study to evaluate the potential for inter-specific competition with resident hymenopteran larval parasitoid species in New Zealand. Information on taxonomic and life history traits were collated from published and unpublished literature, while morphological traits were obtained by measuring specimens in the New Zealand Arthropod Collection. Functional trait information was gathered for 89 parasitoid species, and a hierarchical agglomeration approach was used to cluster species based on similarity. A principal component analysis identified several key traits, including host development (idiobiosis, koinobiosis), site of development (ectoparasitoid, endoparasitoid), progeny per host, the host stage attacked, and ovipositor morphology. Analysis show that M. pulchricornis has the potential to compete with a different range of species, including biocontrol agents, and endemic or native species. Functional trait information using the literature and taxonomic collections can be used to complement current risk assessment tools.

Insects comprise the majority of non-native animal species established around the world. However, geographic biases in knowledge hamper an overall understanding of biological invasions globally. A dataset of accidentally introduced non-native insect species established in New Zealand was compiled from databases, entomological literature, and examination of specimens in the New Zealand Arthropod Collection. For each non-native species, the first recorded location and first recorded date of detection was obtained. Excluding intentionally introduced species, there are 1477 non-native insect species successfully established in New Zealand across 16 orders, 234 families and 1017 genera. Four orders (Coleoptera, Hemiptera, Hymenoptera and Diptera) contributed 77.5% of all established insect species. Herbivores represented the largest feeding guild (47.7%), comprised of polyphagous (48.3%) or oligophagous (39.7%) species. The majority of these species originated in the Australasian (36.7%) and Palearctic regions (24.8%). Regression trees, using a binary recursive partitioning approach, found the number of international tourist arrivals, exotic vegetation cover, and regional gross domestic product were the main factors explaining spatial patterns of recently established species. Gross domestic product best explained temporal patterns of establishment over the last century. Our findings demonstrate that broad-scale analyses of non-native species have important applications for border biosecurity by providing insight into the extent of invasions. In New Zealand, the current trajectory indicates fewer non-native species are establishing annually, suggesting biosecurity efforts are being effective at reducing rates of establishment.

The endemic New Zealand weta is an enigmatic insect. Although the insect is well known by its distinctive name, considerable size, and morphology, many basic aspects of weta biology remain unknown. Here, we employed cultivation-independent enumeration techniques and rRNA gene sequencing to investigate the gut microbiota of the Auckland tree weta (Hemideina thoracica). Fluorescence in situ hybridisation performed on different sections of the gut revealed a bacterial community of fluctuating density, while rRNA gene-targeted amplicon pyrosequencing revealed the presence of a microbial community containing high bacterial diversity, but an apparent absence of archaea. Bacteria were further studied using full-length 16S rRNA gene sequences, with statistical testing of bacterial community membership against publicly available termite- and cockroach-derived sequences, revealing that the weta gut microbiota is similar to that of cockroaches. These data represent the first analysis of the weta microbiota and provide initial insights into the potential function of these microorganisms.

The potential for novel pests to attack indigenous plants can be examined in non-native ranges of these plants. We used perennial native New Zealand plant species growing in botanic gardens and on public spaces in southern California to explore new associations between these plants, the bacterium Xylella fastidiosa, and its vector, the invasive insect pest, Homalodisca vitripennis (the glassy-winged sharpshooter), both of which are not yet present in New Zealand. Further, we examined the biocontrol potential of egg parasitoids against H. vitripennis on New Zealand plant hosts in southern California. We make the case for the inclusion of biocontrol as an early-response strategy against H. vitripennis should this pest invade New Zealand, and outline the steps required to make biocontrol part of a rapid-response management plan should an incursion and localized establishment occur.

Projects involving citizen scientists have greatly increased over the last decade and understanding errors associated with such projects has been identified as an important step. NatureWatch NZ is a biodiversity recording system accessible to members of the public. The “NZ wasps, ants, bees and parasitoids (Hymenoptera) project” was initiated within NatureWatch NZ in December 2012, and comparisons were analysed between these records and the known Hymenoptera fauna of the New Zealand region. Over the course of 1 year 25 members contributed 360 records from 186 taxa, including the discovery of several introduced species new to New Zealand. There was a strong geographical bias to the records, with the majority being based around the major cities. Aculeates (stinging wasps) were significantly over-represented in the NatureWatch records. Only half (55 %) of taxa were identified to species level, with a further 28 % at genus level, and 17 % identified above genus level (family, order). Furthermore, the majority (65 %) of taxa were recorded only once, and only a few taxa were recorded >5 times (top records were “Ichneumonidae”, “Hymenoptera”, Anthidium manicatum, and Apis mellifera). It is probable that these same biases also exist for many other taxonomic groups in projects operated by citizen scientists lacking set protocols. Caution should be exercised on the subsequent use, compilation, and analysis of citizen science, especially without prior examination of records and potential biases.

The direct and indirect interactions of invasive ants with plants, insect herbivores, and Hemiptera are complex. While ant and Hemiptera interactions with native plants have been well studied, the effects of invasive ant–scale insect mutualisms on the reproductive output of invasive weeds have not. The study system consisted of Argentine ants (Linepithema humile), boneseed (Chrysanthemoides monilifera monilifera), and sap-sucking scale insects (Hemiptera: Saissetia oleae and Parasaissetia nigra), all of which are invasive in New Zealand. We examined the direct and indirect effects of Argentine ants on scale insects and other invertebrates (especially herbivores) and on plant reproductive output. Argentine ants spent one-third of their time specifically associated with scale insects in tending behaviours. The invertebrate community was significantly different between uninfested and infested plants, with fewer predators and herbivores on ant-infested plants. Herbivore damage was significantly reduced on plants with Argentine ants, but sooty mould colonisation was greater where ants were present. Herbivore damage increased when ants were excluded from plants. Boneseed plants infested with Argentine ants produced significantly more fruits than plants without ants. The increase in reproductive output in the presence of ants may be due to increased pollination as the result of pollinators being forced to relocate frequently to avoid attack by ants, resulting in an increase in pollen transfer and higher fruit/seed set. The consequences of Argentine ant invasion can be varied; not only does their invasion have consequences for maintaining biodiversity, ant invasion may also affect weed and pest management strategies.

The Argentine ant, Linepithema humile (Mayr), is an invasive species that has been associated with various negative impacts in native communities around the world. These impacts, as for other invasive ants, are principally towards native ant species, and impacts on below-ground processes such as decomposition remain largely unexplored. We investigated the relationship between Argentine ants and invertebrate fauna, litter decomposition and soil microbial activity between paired invaded and uninvaded sites at two locations in Auckland, New Zealand, where there has been no research to date on their impacts. We examined the diversity and composition of invertebrate and microorganisms communities, and differences in soil and litter components. The composition of invertebrates (Order-level, ant and beetle species) was different between invaded and uninvaded sites, with fewer ants, isopods, amphipods, and fungus-feeding beetles at the invaded sites, whereas Collembola were more abundant at the invaded sites. There were significant differences in soil chemistry, including higher carbon and nitrogen microbial biomass at uninvaded sites. Several litter components were significantly different for Macropiper excelsum. The fibre content of litter was higher, and key nutrients (e.g. nitrogen) were lower, at invaded sites, indicating less breakdown of litter at invaded sites. A greater knowledge of the history of invasion at a site would clarify variation in the impacts of Argentine ants, but their persistence in the ground litter layer may have long-term implications for soil and plant health in native ecosystems.

Numerous ant species are being transported around globe through international trade, many of which become invasive. To mitigate the potential impacts of invasive ant species, an assessment system is needed which is simple, can be tailored for specific-user and regional requirements, and has the potential to integrate a variety of additional information. Here we present such a system, which has been used in New Zealand to determine which ant species pose the greatest threat to natural ecosystems. However, the scorecard system could be applied widely around the globe for assessing the threat of invasive ant species.

Despite their economic and environmental impacts, there have been relatively few attempts to model the distribution of invasive ant species. In this study, the potential distribution of six invasive ant species in New Zealand are modelled using three fundamentally different methods (BIOCLIM, DOMAIN, MAXENT). Species records were obtained from museum collections in New Zealand. There was a significant relationship between the length of time an exotic species had been present in New Zealand and its geographic range. This is the first time such a time lag has been described for exotic ant species, and shows there is a considerable time lag in their spread. For example, it has taken many species several decades (40–60 years) to obtain a distribution of 17–25% of New Zealand regions. For all six species, BIOCLIM performed poorly compared to the other two modelling methods. BIOCLIM had lower AUC scores and higher omission error, suggesting BIOCLIM models under-predicted the potential distribution of each species. Omission error was significantly higher between models fitted with all 19 climate variables compared to those models with fewer climate variables for BIOCLIM, but not DOMAIN or MAXENT. Widespread species had a greater commission error. A number of regions in New Zealand are predicted to be climatically suitable for the six species modelled, particularly coastal and lowland areas of both the North and South Islands.

The abundance, richness and trophic structure of beetle assemblages (Insecta: Coleoptera) from remnant eucalypt woodlands of the Northern Plains, Victoria, is documented. Three sampling methods (pitfall trapping, direct searching, sweep netting) were used to sample beetles in four seasons over a year. A total of 4487 beetles were sorted into 342 morphospecies from 46 families. Pitfall trapping alone caught the greatest number of families (72%), morphospecies (56%) and specimens (50%). However, direct searching and sweep netting yielded a large number of morphospecies not caught by pitfall trapping. Sampling in summer yielded the greatest number of families (78%) and morphospecies (55%) but the most specimens (31%) were caught during winter. The proportions of different trophic groups varied little across different seasons but greatly for sampling methods. Pitfall trapping caught a higher proportion of predators and a lower proportion of herbivores than other sampling methods. Direct searching caught mostly herbivores, whilst sweep netting captured a large number of fungivores. The results have implications for the design of sampling sets for inventory surveys of invertebrate groups.

Pitfall trapping is one of the most commonly used methods to survey surface-active invertebrates, but has many potential biases that may affect the catch of invertebrates. The distance between pitfall traps (inter-trap spacing) is one such factor. The abundance, richness and composition of invertebrate orders, and species of ants and beetles was examined for three commonly used inter-trap spacings (1, 5, 10 m) in a grassy-woodland ecosystem in Victoria, Australia. Abundance and composition was not significantly different between treatments for any taxa. A significant difference in richness between treatments was found only for beetles. The 5 and 10 m treatments had a significantly higher number of beetle morphospecies than the 1 m treatment. Knowledge of such biases, and how subtle variations in trap design affect efficiency, is important for designing invertebrate surveys.