Updates

  • June 2020 project update and next steps

    The project has now reached a key mid-point. In May 2020 CABI submitted final reports to Manaaki Whenua Landcare Research on the field survey and host testing completed to date. Manaaki Whenua Landcare Research (MWLR) has now completed their review of this data, plus earlier ginger biocontrol work to determine the next steps for the project.

    This has coincided with the impacts of the COVID 19 virus, which has significant implications for international travel and coordination with the Indian Government.  The findings to date and the next steps for the project are outlined below.

    Five agents have now been collected and undergone host testing in the UK; two stem mining flies, a weevil, a leaf feeding moth and a hispine beetle. Three of these have now been discarded as potential agents, and two remain as potential options but with key questions regarding effectiveness and host specificity requiring further evidence to resolve.

    The leaf feeding moth (Artona flavipuncta), has been discarded as a potential agent by MWLR as trials showed larvae were able to feed and can be reared on many non-target plants. 

    The hispine beetle (Prionispa patra), first collected in October 2019, has also been discarded as a potential agent by MWLR as it also showed a broad host range in adult feeding trials and shows almost no significant damage to the plant in the field in India.

    Stem Mining Flies - Merochlorops species:

    Following on from the taxonomic inspection of the stem-mining flies by a Dipteran expert in the UK, Manaaki Whenua Landcare Research conducted DNA molecular analyses which supported the separation of the 4-spot and 3-spot flies based on the morphological differences observed. 

    Based on all results to date, the 4-spot fly was confirmed to have a wide host range outside the subfamily, and although there remain gaps in the plant species representation, it is likely that it will attack a wide range of species and be unsuitable as a biocontrol agent here.  MWLR have therefore decided to abandon this species from further testing or consideration.

    Additional host-testing was set up by CABI for the newly defined 3-spot species following July and October 2019 collections. These trials were carried out primarily to determine if the 3-spot fly would attack our NZ wild ginger. Unfortunately, these trials failed to return any positive controls in the laboratory in the UK.  

    For a host specificity test to be recorded as accurate and definitive, more than 3 positive results of feeding, egg-laying and larval development of the insect on the target host plant are required. These are called controls.  If more than 3 replicates of the control plants showing feeding, egg-laying and development are obtained and we then get 3 or more replicates of the non-target plants showing no feeding, egg-laying or development in the same series of tests, this test can then be recorded as an accurate and positive result.  In all of the testing done indoors at CABI to date, we have very few occasions where this has occurred.

    The 3-spot fly remains difficult to rear and test in the laboratory in the UK. Field observations and lab results to date still suggest that the 3-spot fly is likely to be more specific, but so far this species has not been successfully reared in the laboratory from NZ wild ginger. It may be that it is too host specific and unable to attack our hybridised NZ wild ginger.  There is also the possibility that the condition and availability of wild ginger in laboratory conditions in the UK may be impacting the success of the rearing. In general, the flies have proven hard to rear in captivity as each larva requires their own stem to develop fully.

    In addition, following the last collection, further taxonomic analysis of 3-spot specimens determined that there are two 3-spot fly species which have only very subtle morphological differences. These have been subsequently described by an expert taxonomist as Merochlorops incisus and Merochlorops uncinatus.  M. uncinatus was the more common of the two in field collections, and this species would be the target for further work. 

    Based on the results to date, Manaaki Whenua Landcare Research has recommended that the 3-spot fly (M. uncinatus) be imported into New Zealand for further host-testing in containment facilities. This will allow access to vigorous and more abundant NZ wild ginger for rearing and host specificity tests to definitively determine if it is the specificity of the agent or the quality of the ginger material that is the reason for the rearing/testing difficulties.

    Ginger Weevil - Metaprodioctes trilineata:

    Testing has shown the adult ginger weevil has a relatively wide feeding host range in the laboratory but appears to have a narrow host range for oviposition, larval feeding and development. However, there is still not sufficient replication of results to accurately describe their host range and impacts to the level required for an EPA application, again as a result of insufficient ‘positive controls’ as described above.  These agents could still prove to be too non-specific for release. 

    Manaaki Whenua Landcare Research have therefore recommended that the weevil be imported into New Zealand to carry out more host testing in containment. This will improve result replication and broaden the range of potential hosts available to be tested, with the goal to obtain robust enough results to support an application to the EPA for release. Conducting the further tests in New Zealand has the benefit of improved access to more vigorous and abundant NZ wild ginger, as well as better access to other non-target species for host testing to improve plant species representation in these tests.

    These next steps for both the weevil and the 3-spot fly will rely on obtaining third party approval from Indian authorities to import these agents, and the resumption of international travel. The timeline for further work has therefore been extended and will need to be reviewed as the travel situation develops. The earliest a collection for import could occur would be October 2021.

    Regards,

    The Stop Wild Ginger Stakeholder Group

     

  • Update from CABI and MWLR

    September 2019

    The Centre for Bioscience and Agriculture International (CABI) undertook the July 2019 survey and collection in Sikkim, India as agreed, and managed to collect a good number of stem-mining flies, some weevils and the leaf-feeding moth. These were taken back to the UK for rearing and host testing in their quarantine facility.

    Following on from the taxonomic inspection of the Merochlorops dimorphus stem-mining by a Dipteran expert in the UK, Manaaki Whenua Landcare Research (MWLR) have conducted DNA molecular analyses and confirmed that there are two different species of Merochlorops dimorphus stem-mining flies, a three spot and a four spot. CABI staff managed to split these two types of flies apart from their collections in July and set up new host-testing experiments for each species to ascertain their host range and biocontrol potential.  It is too early for the results yet, as CABI are waiting for the new generation of flies to emerge from the plants. However, as reported from the earlier host testing, the expectation is that only one of the species, the three spot, is host specific, but there is still a question as to whether it will feed on the New Zealand ginger.  CABI are planning another collection in October so they will have enough flies for the host testing to be completed by the end of this calendar year. A decision will then be made, based on the outcome whether to continue with them or discard them.

    The Metaprodioctes trilineata weevils that feed on all parts of the ginger plants as adults and whose larvae feed in the rhizomes, are showing a broad feeding range as adults. MWLR still need to assess whether the adults discriminate between plant species when laying eggs and whether the larvae are capable of feeding on other plant species. This is proving to be a difficult process in quarantine with restricted plant material and space at CABI in the UK.  To address this MWLR will be sending more NZ ginger rhizomes to CABI to boost their plant numbers for rearing and host-testing experiments. If this species is host specific, MWLR are expecting to apply for a 3rd party export to NZ, to the Indian National Biodiversity Authority (NBA) and to import the weevils into NZ for further work. CABI hope to complete the host testing of the weevil this year and a final decision about whether to continue with this species will then be made. 

    As for the leaf-feeding moth, Artona flavipuncta, it appears that the larvae feed and can be reared on many non-target plants. Although there is still a question as to whether the adult moths would oviposit on ginger only, the expectation is that they won’t, so we have discarded this species for further work at this time.

    For the next survey and collection trip in Sikkim in October, CABI have been asked to look for and collect the Hispine beetles, and begin host testing them, to enable them to switch focus to these species if the other insects prove to be non-host specific or are unable to be reared for field release at this time.

    Regards,
    The Stop Wild Ginger Stakeholder Group

  • News from the UK...

    Results have just returned from the Centre for Bioscience and Agriculture International (CABI), our agent in London who are conducting the initial host testing on our stem-mining fly. A number of flies did hatch from the ginger stems collected in India and exported to the UK, however, closer taxonomic inspection by a Dipteran expert suggests that there are in fact two, separate species of flies that emerge from identical pupae in the ginger stems. These probable two species are only distinguished as adults by a frontal protuberance and a difference in genitalia, both only observable under a microscope. The initial findings from this round of testing also indicate that one of the species is host-specific but will not feed well on the hybrid of ginger we have here in New Zealand and the other species will feed on our ginger but is non-host specific, meaning it could feed on other, desirable species we have here.

    CABI and Manaaki Whenua Landcare Research (MWLR) have agreed to one more collection of the fly in July from the Sikkim region of India in order to categorically rule out the use of the fly as a biocontrol agent and to definitively establish that there are indeed two species (through molecular analysis) and to test pure cultures of the flies with good sex ratio’s and population numbers in order to be sure that the lack of positive controls on our hybrid species were not due to other variables. If the results from that collection are similar or inconclusive, then the focus will shift to the weevil and hispine beetles.

    Previous research has shown that the weevil can be difficult to raise in containment but this insect is known to be restricted to ginger species as hosts for larval development. The risk to non-target plants is yet to be completely determined. The current plan is for CABI to survey the Sikkim region in July and collect as many of the adult male and female weevils as possible before the monsoon season. A second survey will be conducted in October. A student from the local university will conduct pre-surveys to identify sites with high numbers of weevils.

    The two hispine beetles are approved for export but are relatively under-researched still and will be collected along with the weevil so that host testing can begin on them this northern summer.  While the results for the stem-mining fly are disappointing, the weevil is still significantly promising and the fly may still have potential after the results of the July collection. An update will be provided after the bi-annual stakeholder meeting in June. For further information, please contact our Financial Manager, Ashlee Lawrence at ashleel@nrc.govt.nz 

    Regards,
    The Stop Wild Ginger Stakeholder Group

  • Holiday News

    Meri Kirihimete to all our supporters!

    We have recently had some excellent news from our Landcare Research partners, that CABI UK have successfully negotiated with the Indian authorities and exported specimens of the stem-mining fly to their facilities in the UK. They are now waiting on the larvae to emerge from stems of wild ginger that they collected to then proceed with breeding and host-testing trials. 

    We expect further updates in the New Year, keep an eye out for our newsletter with further information!

     

    -The Stop Wild Ginger Stakeholder Group

  • Our Plan For The Next Three Years....

    Thanks to Ministry of Primary Industries and our stakeholder partners, we now have the funds to finish our research in Northern India over the next three years and hope to have at least two successful introductions of a biocontrol agent by 2021. We are currently subcontracting Manaaki Whenua Landcare Research to oversee the research and quarantine testing.

    We will be holding bi-annual stakeholder meetings every six months (dates and locations TBC), which any member of the public is more than welcome to attend. These meetings will be attended by senior scientists from MWLR who will present on the latest findings and project progress to all of our stakeholders. Meeting times and dates will be posted to this website and if you would like to attend please email our Finance Manager, Ashlee Lawrence at ashleel@nrc.govt.nz to confirm numbers.  Newsletters such as this one will also be posted to the website every three months, and updates as required.

    The first updates from MWLR were received this week - they have signed off a contract with CABI UK to source, collect, host test, rear and ship potential biocontrol agents for wild ginger. CABI have been negotiating with Indian authorities for permission to collect and ship the potential biocontrol insects out of India and to the UK for quarantine. These negotiations have been successful and the three-year programme for exploration and surveys can begin mid-October, 2018. This is great news for the project as these negotiations have taken a number of years with many setbacks.

    As the project moves forward and biocontrols are imported, we will be attending a number of Field Days and agricultural shows to raise awareness of wild ginger and our research. We will be using these opportunities to discuss potential release sites with the public and to identify any areas besides Russel State and Waipoua Forests that urgently need assistance. These sites will have to meet a number of criteria as ‘nursery sites’ to foster growing populations of insects that will then be able to move to other infested areas.

    The next few years look to be very positive for the project, if you would like any further information or details, please email our Finance Manager on the above email and don’t forget to keep an eye on this page for updates!

     

     With Thanks,

     The Stop Wild Ginger Stakeholder Group

     

  • Fantastic News!

    Thanks to all your hard work dropping pins, we now have almost $900,000 to continue our biocontrol research.

    Thanks for  your support.

    The Stop Wild Ginger Stakeholder Group

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