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Perennial ryegrass (Lolium perenne L.) grows in association with a fungal endophyte Epichloe festucae var. lolii (Latch, Christensen & Samuels) Bacon & Schardl, which produces alkaloids that protect the grass against grazing by mammals and insects. These alkaloids are found in guttation fluid (xylem sap exuded from leaves through special structures known as hydathodes) and have the potential to impact on beneficial invertebrates in pastoral ecosystems. Newly emerged adults of the parasitoid Microctonus aethiopoides Loan (Hymenoptera: Braconidae) were supplied with guttation fluid from pot-grown ryegrasses infected with three different strains of endophyte (standard, AR37, AR1) or no endophyte collected at different times of the year, or water, sucrose solution or no liquid. Longevity was compared when individuals were held in separate vials in controlled environment room at 20oC with 16:8 h light:dark photoperiod. An enzymatic method was used to measure sugars in guttation fluid samples collected on three dates. Guttation fluid from endophyte-infected grasses was found to have no detrimental effect on M. aethiopoides longevity and to contain glucose and fructose. Guttation fluid from AR37-infected ryegrass collected in autumn increased insect longevity compared to water and fluid from standard-type infected ryegrass by 26% and 24% respectively. The lack of available food sources in New Zealand ryegrass-dominant pastures means that guttation fluid from AR37-infected ryegrass in autumn may contribute to M. aethiopoides efficacy as a biocontrol agent through enhanced longevity.

Two species from the genus Microctonus Wesmael (Hymenoptera: Braconidae) have been introduced into New Zealand as biocontrol agents of pest weevils in pasture. Both parasitoids have similar life cycles and co-exist in pasture along with their respective weevil hosts. However, winter parasitism rates by M. hyperodae Loan are low in comparison to the Irish biotype of M. aethiopoides’ Loan. Population studies at two Waikato sites over three consecutive seasons of parasitoid activity showed that M. aethiopoides recovered from near extinction each spring and built up to effective levels by winter because hosts were available continuously throughout summer and autumn. In contrast, M. hyperodae began each season at higher larval populations and parasitism levels than M. aethiopoides, but populations and parasitism levels declined during late summer and early autumn due to low host availability. The contrast between species is consistent with the high levels of endophyte-conferred pest-resistant grass in the pastures, which impacts strongly on M. hyperodae’s host weevil abundance during summer but has no effect on M. aethiopoides’ host weevils which feed only on clovers. It was accentuated by a warming climate with the now regular occurrence of a third host generation after most M. hyperodae adult activity had ceased.

New Zealand’s indigenous and productive ecosystems are highly vulnerable to invasive species: therefore, New Zealand has stringent biosecurity legislation which encompasses the introduction of new biological control agents. To introduce a new agent, an application is made to the Environmental Protection Authority (EPA). The risk assessment carried out by the applicant is reviewed and a decision is made by an independent committee following public submissions and Māori consultation. An application will be declined if it is likely the new agent will cause significant adverse impacts on any indigenous species within its natural habitat, on natural habitats or on New Zealand’s inherent genetic diversity. Contrasting case studies are presented on two generalist arthropod biological control agents, one for a predatory mirid Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) where the application was declined, and the other a predatory mite Neomolgus capillatus (Kramer) (Acarina: Bdellidae) which was considered for an application.

Background Yersinia entomophaga is an entomopathogenic bacterium that is active against scarab beetles, among other insects. In New Zealand, the African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae), is a major pest of pastures and arable crops but very few control options exist and no insecticides are registered for use in established pastures. Results In laboratory bioassays, H. arator adults were susceptible to a bait containing Y. entomophaga at low doses. This bait was more effective against H. arator adults during spring than autumn in small-scale field plots (320 mm diameter). A large-scale field trial (40 × 40 m plots) reduced adult numbers substantially: approximately twice as many beetles were captured in pitfall traps from untreated plots compared with plots treated with the Y. entomophaga bait at 70 kg ha-1 . This single bait application in spring also reduced subsequent larval populations in summer. Conclusions Heteronychus arator is a difficult pest to manage using chemical insecticides. This biopesticide with Y. entomophaga as the active ingredient offers a new solution for New Zealand pastures, with potential for application to other crops affected by H. arator and for control of other pests. © 2020 Society of Chemical Industry.

The production and pest susceptibility of eight clover cultivars were compared over two years in the pasture at two contrasting sites: a rain-fed Waikato cattle-grazed pasture and an irrigated Cant...

It is well understood that damage by insect pests can have serious consequences for pasture resilience. However, the impacts of climate change on pastoral systems, the responses of insect pests, and implications for pest impact mitigation are unclear. This paper reviews pest responses to climate change, including direct impacts such as temperature and carbon dioxide levels, geographic range expansion, sleeper pests, and outbreaks resulting from disturbance such as drought and farm system changes. The paper concludes with a plea for transdisciplinary research into pasture resilience under climate change that has insect pests as an integral component – not as an afterthought.

Environmental risk assessments (ERAs) are required before utilizing exotic arthropods for biological control (BC). Present ERAs focus on exposure analysis (host/prey range) and have resulted in approval of many specialist exotic biological control agents (BCA). In comparison to specialists, generalist arthropod BCAs (GABCAs) have been considered inherently risky and less used in classical biological control. To safely consider exotic GABCAs, an ERA must include methods for the analysis of potential effects. A panel of 47 experts from 14 countries discussed, in six online forums over 12 months, scientific criteria for an ERA for exotic GABCAs. Using four case studies, a three-tiered ERA comprising Scoping, Screening and Definitive Assessments was developed. The ERA is primarily based on expert consultation, with decision processes in each tier that lead to the approval of the petition or the subsequent tier. In the Scoping Assessment, likelihood of establishment (for augmentative BC), and potential effect(s) are qualitatively assessed. If risks are identified, the Screening Assessment is conducted, in which 19 categories of effects (adverse and beneficial) are quantified. If a risk exceeds the proposed risk threshold in any of these categories, the analysis moves to the Definitive Assessment to identify potential non-target species in the respective category(ies). When at least one potential non-target species is at significant risk, long-term and indirect ecosystem risks must be quantified with actual data or the petition for release can be dismissed or withdrawn. The proposed ERA should contribute to the development of safe pathways for the use of low risk GABCAs.

The lack of plant biodiversity in New Zealand pastoral ecosystems may limit the abundance and diversity of generalist parasitoids and predators, predisposing these ecosystems to pest outbreaks. To test this hypothesis, patches of turf were established in existing pasture during spring 2016. Four treatments of increasing plant complexity were established, commencing with ryegrass alone, and increasing exponentially up to eight species of forage plant per patch. In the summer of 2017, insects were collected from the patches and control plots using suction to assess whether or not plant diversity had influenced the abundance and diversity of lacewings and parasitic Hymenoptera aggregating in the patches. Plant species richness had no impact on lacewing abundance but fewer parasitic Hymenoptera were recovered from the ryegrass-only plots compared with more species rich plots. Also, a wider range of parasitoid families were represented in the more diverse plant treatments compared with the less diverse treatments. Such diversity may have beneficial impacts on the stability of pasture ecosystem and the risk of pest outbreaks.

Due to typesetting errors, Table 5 was not displayed correctly in the initial online publication. The original online article has been corrected.

The increased use of narrow-leaved plantain Plantago lanceolata as forage in New Zealand has led to the emergence of two native moths, Scopula rubraria and Epyaxa rosearia, as significant pests. Plantain is known to contain defensive compounds against insects and a laboratory study was undertaken to compare the growth and development of both moth species on four plantain cultivars and one breeding line. Larval feeding and development was found to vary with plant line and leaf age, with Ceres Tonic and especially SF Boston the most favourable plantain lines for both pests. No E. rosearia completed larval development on mature foliage from Luisetti Tuatara or the breeding line JC Upright. While the differences between plant lines appeared to be related to foliar digestibility and metabolisable energy indices, rather than glycoside levels, the results indicate that narrow-leaved plantain has attributes that could be exploited to achieve better resistance against these pests.

Two native geometrid moths, Scopula rubraria and Epyaxa rosearia, have emerged as major pests of narrow-leaved plantain, a forage plant that has grown in popularity in summer-dry regions of New Zea...

Clovers (Trifolium spp.) are vulnerable to a large number of invertebrate pests so pest resilience amongst 19 leading commercial or near release New Zealand-bred clover cultivars was compared. Laboratory feeding choice tests comparing foliage from the test clovers against Grasslands Kopu II as the standard confirmed that red clovers (T. pratense) were less preferred than white clovers (T. repens) by adult clover root weevil and clover flea. Grey field slug showed no preference between red and white clovers, with the white clover Grassland Prestige performing the best. Porina larvae had lowest weight gains on strawberry clover (T. fragiferum). Subsequent tests using neonate greenheaded leafroller larvae and an artificial diet made with freeze-dried foliage from cultivars in the most and least preferred subgroups indicated antifeedant compounds, rather than leaf morphology, are likely responsible for differences in feeding preferences between red and white clovers.

The African black beetle (Heteronychus arator F.) is a pest of pastures in the North Island of New Zealand. Except during dispersal activity, adult beetles live in the soil and feed at the base of grass stems during spring and fall and to a lesser amount over-winter. Larvae develop over summer months feeding on the grass roots. We tested three life-stages of H. arator (first and third instar larvae and adults) for susceptibility to the four entomopathogenic nematode (EPN) species present in New Zealand: Steinernema carpocapsae, Steinernema feltiae, Heterorhabditis bacteriophora and Heterorhabditis zealandica. All H. arator stages were found to be susceptible to EPN, but different life-stages varied in susceptibility to EPN species. Based on our laboratory assays, we chose to target adult beetles using S. carpocapsae. We ran three field experiments, one in spring and two in fall but the EPN did not reduce beetle numbers in any experiments. Field temperatures were cool, but within the stated thermal niche breadth of S. carpocapsae for killing hosts. Sampling on nematode-treated plots revealed several susceptible lepidopteran larvae clearly infected with S. carpocapsae but no infected H. arator. We tested the hypothesis that the effective niche breadth for killing hosts may vary with host-susceptibility. We studied the temperature response of S. carpocapsae against Galleria mellonella and H. arator at 12.5, 15, 18, 20 and 25 °C. While S. carpocapsae caused significant mortality of G. mellonella at all temperatures, no H. arator mortality was seen at 12.5 or 15 °C despite using a high nematode rate and incubating for two weeks. Our data highlight the importance of testing susceptibility of different insect life stages at the temperatures likely to be encountered in the field following nematode application.

The article title was incomplete in the initial online publication. The original article has been corrected.

White clover cryptic virus-2 is recorded for the first time in New Zealand in three commercial cultivars of white clover: Grasslands Huia, Grasslands Kopu II and Grasslands Sustain. An RT-PCR assay was used to amplify and sequence a ~590 bp fragment of the coat protein gene.

The distribution and abundance of cryptic viruses (Partitiviridae) in natural and agricultural systems have received little attention. White clover cryptic virus-1 (WCCV-1) was detected infecting white clover plants and seed growing in New Zealand, but was not detected in field collections and in only two of 114 seedlings grown from seed collected in eastern Australia using enzyme-linked immunosorbent assay and RT-PCR. WCCV-1 was detected at high incidences (14–48%) in the cultivars Huia, Kopu II and Tahora and at low incidences (0–7%) in Aran, Haifa, Ladino, Siral and Sustain white clovers. WCCV-1 remained viable in seed stored for 50 years. The results are compared with another group of obligate seed-transmitted pasture microbes: the fungal endophytes of perennial grasses.

Classical biological control of insects has a long history of success, with high benefit–cost ratios. However, most attempts to introduce a biological control agent have been unsuccessful, largely because the agent does not establish in the new environment. This perspectives paper discusses the possibility that even successful biological control may eventually fail, although records show that this is far from a common event. A documented example of eventual biological control failure is discussed and the prospect for future failures analyzed. Part of this analysis is based on an introduced weevil pest in New Zealand and its successful parasitoid biological control agent. The potential fragility of this host–parasitoid relationship is considered, as well as why it may indeed be starting to show signs of instability; this is particularly from the point of view of New Zealand’s often species-poor agricultural ecosystems.

Twenty-nine white-clover pastures from the North Island of New Zealand were tested by enzyme-linked immunosorbent assays for five viruses: Alfalfa mosaic virus (AMV), Beet western yellows virus (BWYV) Red clover necrotic mosaic virus (RCNMV), Soybean dwarf virus (SbDV) White clover mosaic virus (WClMV) and also for potyviruses. All the pastures were infected; most with WClMV and/or AMV and SbDV. The high incidence of SbDV was an unexpected result and although SbDV has little impact on white clover productivity its effect in mixed infections with AMV or WClMV is unknown. No potyvirus and only single infections of BWYV and RCNMV were detected. There was lower incidence of SbDV in the Bay of Plenty compared to Waikato. The Bay of Plenty samples had a higher ratio of AMV to other viruses than the Waikato.

The introduced parasitoid Microctonus aethiopoides (Hymenoptera Braconidae) appears to be an effective biocontrol agent for clover root weevil Sitona lepidus Gyllenhal (Coleoptera Curculionidae) in New Zealand pastures As these pastures lack accessible nectar sources hemipteran honeydew may be the most readily available energy source for the parasitoid Experiments were undertaken to compare longevity of newly emerged M aethiopoides adults caged on white clover firstly with and without black legume aphid Aphis craccivora Kock (Hemiptera Aphididae) and then with additional water and sucrose solution treatments Parasitoids with access to aphid honeydew lived significantly longer (mean longevity 81 days) than those with water or no liquid (both 68 days) but not as long as those fed sucrose solution (109 days) Therefore the abundance of aphids commonly present on clovers may enhance M aethiopoides longevity and therefore efficacy in the field especially in mid spring when host availability is very low

[EN] Terrestrial invertebrate species play a dominant role in the trophic dynamics of agricultural ecosystems. Subtle changes in the composition of communities and species interactions at different trophic levels, and role of ecosystem engineers can dramatically modify the effects of invertebrates on plant productivity in agricultural systems. The effect of climate change on relevant invertebrates in agricultural systems, and their potential to adapt or move is discussed. All terrestrial systems (including forestry and pasture) are considered, although the main focus is on crop production systems. Our treatise centres on whole organisms (as opposed to genetic information from invertebrates) that play key roles in agricultural systems.Westart with an overview of current thinking on how climate change may affect invertebrates. Then, recognizing the great invertebrate biodiversity associated with agro-ecosystems, the review focuses on three key groups - soil invertebrates, biological control agents and pollinators. A variety of research gaps became apparent during the course of our review. Specific conclusions regarding the impact of climate change on particular elements of invertebrate genetic resources in agriculture are not possible yet. Existing evidence suggests that three general assumptions can be made. First, it is probable that climate change will disrupt to varying degrees the role and use of invertebrates in agriculture, especially sustainable agriculture, even though the precise nature of the disruptions is not yet known. Second, without intervention, these disruptions will result in production losses particularly in sustainable agriculture, even though the scale and extent of the losses is not yet known. Third, the extent of some of the losses will justify intervention to facilitate adaptations of the invertebrates, even though the methods with which to intervene and policies to facilitate this intervention are not yet in place. © 2013 CAB International., This review is based in part on a report that the authors prepared for the Commission on Genetic Resources for Agriculture (CGRFA), at the Food and Agriculture Organization of the United Nations (FAO), Rome, on climate change and invertebrate genetic resources for food and agriculture [277]. We thank Kim-Anh Tempelman and colleagues at the CGRFA for their interest, support and encouragement in preparing that report. We also thank Peter S. Baker (CABI), John Kean (AgResearch Ltd, New Zealand), Graham Walker (The New Zealand Institute for Plant & Food Research Limited), and Craig Phillips (AgResearch Ltd, New Zealand), who contributed Case Studies as indicated; Joop van Lenteren (Wageningen University, The Netherlands), Peter Baker and several anonymous scientists of the CGRFA and FAO who reviewed parts of a draft of the report from which this review was derived; and Rebecca J Murphy (UK) and Dafydd Pilling (FAO) for editorial inputs to that report.

African black beetle, Heteronychus arator (Scarabaeidae), is an exotic pest of pastures in northern New Zealand. Both adults and larvae feed on pasture grasses. Adults disperse by walking (short range) or flying (long range). Dispersal flights are triggered by warm night temperatures in spring and autumn. Short range adult dispersal in search of mates, food or oviposition sites is poorly understood. This study investigated walking activity of H. arator adults over three seasons in New Zealand pastures. Adult walking activity was monitored using pitfall traps along fence lines and in pasture plots on a dairy farm in Waikato, New Zealand, in spring 2013, spring 2014, and autumn 2015. Beetle populations were reduced by application of a biopesticide bait to compare walking activity between treated and control plots for up to 26 days post-treatment. Marked beetles were released into the pasture plots to measure the distance traveled by recaptured individuals. Trap catches along the fence lines were correlated with air temperatures in 2013. Trap catches were male biased in spring 2014 compared with autumn 2015. Trap numbers in the control plots were nearly double that of treated plots in both seasons. More beetles were caught in the pitfall traps at the edges of the treated plots than in the center. Trap catches were consistent throughout the control plot in spring 2014, but in autumn 2015 more beetles were caught in the center of the control plot than at the edges. Few marked beetles were recaptured with dispersal rates estimated as

Biological control systems are integral to New Zealand’s success as a nation reliant on exporting quality agricultural, forestry and horticultural products. The likely impacts of climate change projections to 2090 on one weed and four invertebrate management systems in differing production sectors were investigated, and it was concluded that most natural enemies will track the changing distributions of their hosts. The key climate change challenges identified were: disparities in natural enemy capability to change distribution, lack of frosts leading to emergence of new pests and additional pest generations, non-target impacts from range and temperature changes, increased disruptions caused by extreme weather events, disruption of host-natural enemy synchrony, and insufficient genetic diversity to allow evolutionary adaptation. Five classical biological control systems based on the introduced species Longitarsus jacobaeae, Cotesia kazak, Aphelinus mali, Microctonus aethiopoides and Microctonus hyperodae are discussed in more detail.

A study was carried out to investigate the impact of dung pats on seeding by yellow bristle grass (Setaria pumila) Fresh cow dung was placed on dairy pasture as uniform pats in summer at two sites in Waikato New Zealand and changes in pasture attributes and earthworm abundance monitored over three grazing rotations A zone of repugnance where dairy cows avoided grazing formed out to 40 cm from the centre of the pat It was still evident at 60 days The site with highest yellow bristle grass incidence had taller and bigger yellow bristle grass seed heads in the zone resulting in over twice as much seed as control pasture Earthworm abundance was markedly higher under dung than control pasture the main species being Aporrectodea caliginosa Onfarm management strategies that may accelerate the return of the zone of repugnance to full utilization by stock and minimise weed exploitation are discussed

The clover root weevil Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) became an economically important pasture pest in New Zealand shortly after it was discovered in the Waikato region in 1996. A classical biological programme was initiated and an Irish biotype of Microctonus aethiopoides Loan (Hymenoptera: Braconidae) was released at four sites in the North Island in late summer 2006. These sites in Waikato, Hawke’s Bay and Manawatu (two sites) regions were monitored monthly and parasitoid establishment confirmed at all sites within four months. In the winter of 2007, parasitism exceeded 70%. A widespread North Island drought in summer 2008 had a severe impact on S. lepidus populations at the Waikato and the two Manawatu release sites, resulting in parasitism below detection levels in the following summer. However, populations recovered by autumn. Within three years at the Hawke’s Bay site, M. aethiopoides appears to be suppressing S. lepidus populations and has dispersed naturally over 60 km.

Black beetle (Heteronychus arator) is a sporadic but serious pest of North Island pastures Field trials were established to test the efficacy of insecticides currently registered for use against scarab pests in pasture Three life stages were targeted newly emerged black beetle adults in autumn egglaying adults in spring and newly hatched larvae in early summer Although the insecticides used caused significant beetle mortalities in spring no treatment reduced the subsequent larval populations in summer Similarly while the autumn application caused significant beetle mortality; the number of surviving black beetle adults remaining in the plots was not affected Soil factors and the high mobility of adult beetles are likely to have contributed to treatment failure

New Zealand pastures are host to a range of native and exotic invertebrates. Many of these are pests that feed on the sown plant species, often causing plant death and deterioration in the productivity and persistence of the sward. While most research has focused on pest biology and control, studies of plant productivity show dramatic acute (short-medium term) and chronic (longterm) effects. For example, grass grub has been reported to cause 50% losses to ryegrass swards and Argentine stem weevil can cause a 20% loss of productivity, but the long term effects through loss of the sown species and changes in composition can be even more severe. Insect damage can be exacerbated by other biotic (e.g. weed invasion, grazing animals, plant pathogens) or abiotic factors (e.g. climate, soil fertility) to further reduce plant persistence. Some biotic and abiotic factors may interact with insect pests to have positive effects on pasture persistence, e.g. biocontrol agents that reduce pest density or addition of fertiliser to enable plants to recover from insect damage. For many pasture pests, knowledge of their ecology is based on research from over 20 years ago that, while still valid, needs to be updated to account for modern intensive pasture management practices, such as intensive grazing with a lack of reseeding, and new cultivars. To improve pasture persistence, integrated research programmes are needed that examine the relative importance of all factors contributing to plant survival and develop strategies to mitigate their effects. Keywords: Argentine stem weevil, black beetle, clover root weevil, drought, grass grub, grazing pressure, manuka beetle, nematodes, pasture persistence, pasture quality, pasture yield, porina, soil fertility, striped chafer.

The effects of larval herbivory by clover root weevil (CRW, Sitona lepidus) on seven white clover (Trifolium repens) and two red clover (Trifolium pratense) progenies from plants showing tolerance of CRW in field trials were tested in two controlled glasshouse experiments. CRW larvae recovered from red clover plants were, on average, fewer (6.3 larvae/g root dry weight) and shorter (5.7 mm/g root dry weight) than those from white clover (16.7 larvae, 7.1 mm length).This confirmed previous findings that red clover is an inferior host for this pest. In the first experiment, progeny of four of the white clover selections for CRW tolerance showed high tolerance (shoot dry weights −2.9% to +3.1% different from their respective weevil-free controls) compared with a 13–24% shoot weight loss for two white clover cultivars. These results confirm field trial observations that there is variation for CRW tolerance in white clover and also that CRW tolerance is hereditable in at least some populations. The se...

Two experiments were carried out at Ruakura in soil taken from Whatawhata hill country pasture. The relative susceptibility of several annual clovers (Trifolium spp.) and perennial white clover (T. repens ) to slugs (Deroceras reticulatum), clover root weevil (Sitona lepidus) adults, native crickets (Nemobius sp.) or wheat bugs (Nysius huttoni) was tested by sowing seed of the clovers into separate rows in turf. Susceptibility of clovers to clover cyst nematode (Heterodera trifolii) was tested by sowing each clover variety into Whatawhata soil inoculated with the nematode. Plant growth was assessed in both experiments 4 weeks after sowing. White clover was more susceptible to pests than the annual clovers, with slugs and clover root weevil significantly reducing seedling survival, and clover cyst nematode significantly reducing plant growth. Subterranean clover (T. subterraneum) cv. Denmark was the least affected by pests, showing no significant reduction in survival in the presence of slugs, the most damaging pest, and no significant decrease in plant root and shoot dry weight when exposed to nematodes.

Clover root weevil (CRW) has become one of New Zealand's most serious pasture pests. An Irish ecotype of Microctonus aethiopoides has been released and established as a biocontrol agent. Since early 2006, field samples have been taken to monitor its spread and establishment. The biocontrol agent has established well at sites where 1 000-2 500 parasitised CRW were initially released, except in the Far North, and is spreading at around 15 km/year. Industry field personnel assisted with distributing 2 000 mini-releases (10 parasitised CRW) to areas where CRW was causing damage. One hundred farmers were sent a postal survey and feedback from 59 respondents showed the mini-release approach was successful in terms of distribution of the parasitoid, technology transfer and funder recognition. Based on natural spread from many of the release sites, it is predicted that the parasitoid will be present on most North Island farms by the end of summer 2010/2011. Keywords: Microctonus aethiopoides, biocontrol agent, white clover, Trifolium repens

The egg, larval, pupal and adult abundance of the clover root weevilSitona lepidusGyllenhal (Coleoptera: Curculionidae) was monitored at three sites for the first ten years following the discovery of this exotic pest in the Waikato region of New Zealand. The species went through an initial boom and bust cycle at two sites, with populations reaching up to 1800 larvae m−2. Thereafter, winter larval populations were relatively stable, ranging between 450–750 m−2. Unlike in the Northern Hemisphere,S. lepiduswas found to have two generations a year in the Waikato region of New Zealand. Pasture white clover content at the time of peak adult numbers was positively related to the subsequent peak larval populations for each generation. The factors contributing to the emergence ofS. lepidusas one of the most important pasture pests in New Zealand are discussed.

The effects of root herbivory at five densities of Sitona lepidus larvae (overall means between 4 and 333 larvae m‐2) were assessed over 2 years on newly established perennial ryegrass‐white clover swards in a small plot trial. Initial larval establishment in autumn 2003 was positively related to clover content in plots, and there was no significant impact on clover herbage yield in the first year. Nodule damage in winter 2003 increased with larval density, and results suggested an overcompensatory response in nodule production. A 34–35% reduction in clover yield between highest and lowest S. lepidus densities was recorded for both cultivars in the second year, with greatest losses in spring 2004. This coincided with reductions in clover root and stolon weights. Plant parasitic nematodes and grass grub larvae were most abundant in the plots with lowest weevil numbers. These results confirm field observations that S. lepidus is a major pest of pastures.

Four experimental releases of the parthenogenetic strain of Microctonus aethiopoides from Ireland were made in early 2006 in the Waikato Manawatu (two sites) and Hawkes Bay By early winter establishment was confirmed at all sites with parasitism levels exceeding 10 in the target host Sitona lepidus a serious pest of white clover in New Zealand Subsequent monitoring revealed considerable betweensite variation At the Hawkes Bay and Manawatu Feilding sites where overwintering weevil adults were still present in October over 30 parasitism was found in newly emerged weevils in December 2006 In contrast at the Waikato and Manawatu Bulls sites where there was no overlap of host generations parasitism was below detectable levels during spring and early summer but recovered subsequently The Irish M aethiopoides appears to have four generations a year and diapauses over winter as a first instar larva Following the initial success releases have commenced in other regions

The biological control programme against Sitona lepidus (Gyllenhal) (Coleoptera: Braconidae) commenced in 1998, with the first parasitised weevils imported into New Zealand quarantine in 2000. Extensive collections in Europe confirmed that the solitary endoparasitoid Microctonus aethiopoides Loan (Hymenoptera: Braconidae) was the principal natural enemy of adult S. lepidus. With one exception, all M. aethiopoides reared from S. lepidus collected in Europe have been arrhenotokous. All M. aethiopoides collected from Ireland are thelytokous, which obviates the risk of hybridisation with an arrhenotokous Moroccan strain already established in New Zealand. Levels of parasitism in S. lepidus field-collected from Ireland were low (

A European biotype of Microctonus aethiopoides was identified as the best candidate biocontrol agent for Sitona lepidus a serious New Zealand pasture pest A Moroccan biotype was already present throughout the country and hence there was no requirement to obtain Hazardous Substances and New Organisms (HSNO) Act approval to release new biotypes However as research had shown mating between the two biotypes produced hybrids with poor efficacy against target hosts and that the Moroccan biotype attacked several native weevil genera serious reservations were held about introducing the European biotype Concerns were overcome with the identification of a parthenogenetic strain of European M aethiopoides from Ireland which has little risk of hybridisation and a narrower host range than the Moroccan biotype Following regulation of M aethiopoides as a risk species this strain was considered to be a new organism Approval was sought and gained under the HSNO Act to release the strain

Populations of adult clover root weevil (Sitona lepidus) can infl ict signifi cant numbers of their distinctive feeding notches on the leaves of white clover (Trifolium repens) plants. However, it is assumed that because white clover is bred for defoliation, the damage on established plants has little impact. Two experiments were undertaken to quantify the daily leaf consumption levels of adult weevils, and how this varied with weevil size and sex, clover cultivar and previous leaf damage. Overall, adults consumed between 0.75 and 1.2 mg dry matter/day depending on cultivar and sex. Sexual differences were observed between two contrasting clover cultivars, with females consuming more Grassland Prestige and males Grasslands Kopu. Clover dry matter loss through adult feeding was estimated at about 50 kg/ha from early summer until midwinter in the Waikato, the period of peak adult activity.

Eggs of the univoltine passionvine hopper Scolypopa australis Walker (Homoptera Ricaniidae) are parasitised by Centrodora scolypopae Valentine (Hymenoptera Aphelinidae) The life cycle of the parasitoid and synchronisation with its host was studied in a gully near Hamilton over four years The parasitoid was usually univoltine overwintering in diapause as a prepupa and pupating when host adults were present in midsummer However above average summer temperatures in 1981 resulted in up to 60 of the parasitoid population on a sunny slope with a NE aspect pupating before winter demonstrating that the diapause was facultative Photoperiod was found to be a key factor in diapause maintenance

The effect of cultivation on spider density and diversity was assessed at three sites before and after cultivation in autumn. Linyphiid spiders dominated the fauna at each site (60–90% of the spiders present) with Eperigone fradeorum (Berland) the most common spider (38% of the spiders collected). At all three sites, the populations of both linyphiid and non‐linyphiid spiders decreased significantly after fields were cultivated. Population declines after cultivation did not appear to be related to the intensity of cultivation. This suggests that environmental factors were not an important influence on spider populations, at least in the early part of the experiment. Grazing had a detrimental effect on spider density and diversity. These results suggest that both cultivation and ongoing management can affect spider density and diversity.

Red clover (Trifolium pratense) has been observed to persist longer than white clover (T repens) during field screening of legumes for tolerance of clover root weevil (Sitona lepidus) It has been suggested that this is linked to adult feeding preferences A laboratory trial was undertaken to confirm the feeding preference for white clover over red and to determine whether adults became habituated to red clover over time Groups of clover root weevil adults were caged on either white clover cv Grasslands Huia or 3 lines of Grasslands Pawera red clover At weeks 2 4 6 and 8 subsamples of adults were removed from the cages and were subjected to a 24 h choice test It was found that although adults showed a strong preference for white clover those that had been continuously fed red clover were more likely to feed on red clover in the choice test than those that had previously been fed white clover

Clover root weevil adults collected from the field were held in four contrasting temperature, moisture and feeding regimes for a period of 10 weeks. Temperature was the main factor, inducing changes in adult wing muscle development and egg production. Egg production from females held in the ‘moist winter’ regime (10 °C, 8:16 h light:dark, moist conditions, ample food) increased linearly with time, with 90% of females fully reproductive at 10 weeks. In contrast, when held in the ‘hot drought’ regime (20 °C 16:8 h light:dark, dry conditions, intermittent food), the oviposition rate decreased logarithmically, with 32% of females fully reproductive at 10 weeks. Overall, adult mortality was lower in the ‘moist’ regimes (17%) than the ‘drought’ regimes (29%). Wing muscle development differed between regimes, ranging from 4% of adults with fully developed wing muscles in the ‘moist winter’ regime to 35% in the ‘hot drought’ regime. Clover root weevils are likely to oviposit throughout winter in most of New Zealand, but warm, dry summers will prevent a summer larval generation.

The impact of clover root weevil larval populations was assessed in pure swards of Grasslands Prestige and Grasslands Kopu white clover in a small plot trial Nodule damage was very evident and both cultivars showed significant increases in nodule damage and decreases in percent foliar nitrogen in November in response to increasing winter larval numbers Dry matter production of Kopu in November was related to foliar nitrogen levels

Several novel insecticidal homoerythrinans and dibenzazecines have been synthesised from the alkaloid dyshomoerythrine.

Plots of two cultivars of white clover (Trifolium repens) Grasslands Prestige (smallleaved early flowering) and Grasslands Kopu (largeleaved later flowering) were established in coldframe beds Clover root weevil (Sitona lepidus) larval numbers were manipulated to obtain winter larval densities ranging from 0 to over 1000/m2 Increasing winter larval densities increased Prestige seed production (g/m2) when harvested on 28 December and 10 January and the trend was still evident on 24 January No such relationships were found in Kopu for the early and middle harvests but at the late harvest increasing winter larval densities had a negative impact on seed production The results indicate that the effect of clover root weevil larvae on second year clover seed crops may vary substantially between cultivars and may even be positive rather than negative

The chitinase inhibitor/insect ecdysis inhibitor allosamidin and eight allosamidin analogues have been synthesised from simple carbohydrate starting materials. Allosamidin was assayed against Tineola bisselliella (Hummel) larvae and all nine compounds were examined for their effects on the development of larvae of Lucilia cuprina (Wiedemann). High larval mortality compared to controls resulted when T. bisselliella and L. cuprina larva were exposed to allosamidin. The (1→3) linked regioisomer, the dimeric analogue and the gluco-configurated dimeric analogue of allosamidin all showed high activity against L. cuprina larvae. The regioisomer, the (1→3) linked isomer and its dimeric analogue, as well as the monomer allosamizoline and its regioisomer, were inactive. These new in-vivo results are consistent with known in-vitro insect chitinase inhibition data, in that greatest larval mortality was exhibited by the best inhibitors.

A modified serum‐based bioassay was used to screen plant extracts and assess compound activity against newly hatched larvae of the Australian sheep blowfly Lucilia cuprina. Larval instar mortality and physical appearance were recorded after exposure for 24 h to the treatments. Extracts from New Zealand gymnosperms shown to have activity against L. cuprina larvae were: Podocarpus totara; P. acuteafolius; Dacrycarpus dacrydioides; Halocarpus bidwillii; H. biformis; H. kirkii; Lagarostrobos colensoi; Lepidothamnus intermedius; L. laxifolius; Phyllocladus tricho‐manoides; P. glaucus, and Agathis australis. The phytoecdysones 20‐hydroxyecdysone, 5,20‐dihydroxyecdysone, and ponasterone A inhibited larval moulting. Dyshomoerythrine, dacrysterone, and nagilactone C were insecticidal, with the latter also retarding growth at sublethal rates.

This study focuses on three main groups of organisms: soil invertebrates, biological control agents (BCAs) and pollinators. These groups play key roles in agricultural systems, and have the potential to be used, moved or manipulated for the benefit of agriculture. Soil invertebrates are a key component of agricultural landscapes. They participate in essential soil processes that maintain healthy productive soils in the face of changing environmental conditions. Reducing the diversity of a community of soil invertebrates reduces its beneficial functions and services, with drastic ecological effects such as long-term deterioration of soil fertility and agricultural productive capacity. The introduction of a keystone species may have detrimental or beneficial effects depending on the context. The interaction between soil invertebrates and soil microorganisms is critical: the activities of soil invertebrates regulate microbial activity in soils, and micro-organisms enter into intimate relationships with soil invertebrates to help them degrade highly complex compounds such as cellulose. Different groups of invertebrates provide biological control of crop pests. In many situations, they form the basis of, and tools for, the integrated pest management (IPM) approach. Given that the losses caused by pre- and post-harvest pests can be very substantial, the potential benefits of using invertebrates as BCAs are vast, but as yet only partially tapped. The potential for soil invertebrates to assist in this function is still largely unknown. Pollination services by animals, especially by insects, are among the most widespread and important processes that structure ecological communities in both natural and agricultural landscapes. An estimated 60-90% of the world's flowering plants - including a range of economically important species - depend on insects for pollination. Crop pollination used to be (and often still is) provided by wild pollinators spilling over from natural and semi-natural habitats close to crop fields. This service has generally been free and therefore has received little attention in agricultural management. If wild pollinators are lacking or additional pollination is required, as is the case in many intensive agricultural production systems, farmers in some developed countries can buy or rent managed honeybees or sometimes other species (e.g. bumblebees, alfalfa leafcutter bees and alkali bees). Both options - i.e. use of wild species and managed bees - have recently come under pressure, a development that is sometimes referred to as the 'pollination crisis'. Of the interactions and overlaps between these key groups, that between soil invertebrates and BCAs is the most important, and further research is needed to evaluate the scope and impact of manipulation of the soil ecosystem to conserve or encourage beneficial BCAs. © CAB International 2012., This review is based in part on a report that the authors prepared for the Commission on Genetic Resources for Agriculture (CGRFA at FAO, Rome) on climate change and invertebrate genetic resources for food and agriculture [117]. We thank Kim-Anh Tempelman and colleagues at the CGRFA for their interest, support and encouragement in preparing that report. We also thank Fabian Haas (icipe, Kenya) who contributed a case study as indicated; Joop van Lenteren (Wageningen University, The Netherlands) and several anonymous scientists of the CGRFA and FAO who reviewed parts of a draft of the report from which this review was derived; and Rebecca J. Murphy (United Kingdom) and Dafydd Pilling (FAO) for editorial inputs to that report.

Painted apple moth Teia anartoides Walker (Lepidoptera: Lymantriidae), a native to Australia, was discovered in Auckland, New Zealand in late 1999 and eradicated by 2006. It was recognised in 2002 that biological control would be the most effective long-term control strategy if eradication was unsuccessful, and a search was initiated for potential biocontrol agents in Australia. In 2003, autumn and spring surveys were undertaken in Victoria, Tasmania and South Australia of the guild of parasitoid natural enemies of T. anartoides. Eggs, larvae and pupae were collected and held to rear out any parasitoids. In addition, localised searches were made in Queensland in late 2003 early 2004 and laboratory-reared juvenile stages of T. anartoides were released for recapture in both Victoria and Queensland. Acacia dealbata Link (Fabales: Fabaceae) was the main plant from which T. anartoides was recovered, followed by apple. Most T. anartoides samples were collected from Victoria and Tasmania. Eighteen species from 13 genera of egg, larval and pupal parasitoids were reared and included Diptera (Tachinidae) and Hymenoptera (Braconidae, Encyrtidae, Eulophidae and Ichneumonidae). Of the seven Hymenopteran genera recovered from the larval stage, the most common in Victoria and Tasmania was a previously unidentified larval parasitoid Cotesia Cameron (Hymenoptera: Braconidae) sp. Echthromorpha intricatoria (Fabricius) (Hymenoptera: Ichneumonidae) was the dominant pupal parasitoid. The survey showed that the parasitoid complex associated with T anartoides is structurally very similar to that on other pest Lymantriidae in the northern hemisphere such as gypsy moth (Lymantria dispar L.) (Lepidoptera: Lymantriidae). Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) was recorded for the first time in Australia.