PLANTS AND ENVIRONMENT Plant health surveillance and incursion investigation report: January to March 2019 The Ministry for Primary Industries Investigations transferred to had been found in a cuelure-baited (MPI) Incursion Investigation team surveillance trap in a citrus tree in Otara, and Plant Health and Environment Response Group Auckland. This was thought to be a Laboratory (PHEL) investigate and Fruit-fly interceptions species not present in New Zealand and diagnose suspect exotic pests and The early detection of exotic pests such different to QFF. PHEL identified the diseases in the plant and environment as fruit fly minimises costs associated fly as B. facialis (Diptera: Tephritidae), a sectors. Investigators and scientists are with managing an established population fruit-fly species not previously detected based in Auckland, Wellington, Rotorua through to eradication. The value of in New Zealand and with no English and Christchurch. These teams provide MPI’s targeted surveillance programmes common name. The investigator field investigation, diagnostic testing and was evidenced by the three fruit-fly prepared a rapid risk assessment and the technical expertise to detect and report detections described here. investigation was also incorporated into new pests and diseases affecting plants A single male Queensland fruit fly (QFF), the QFF response. and the environment. They support Bactrocera tryoni, (Diptera: Tephritidae) surveillance and response functions, Great willowherb in wetlands, was found in a fruit-fly surveillance Christchurch including carrying out research trap in a feijoa tree in Devonport, A post on the iNaturalist website and development. Auckland. The cuelure-baited trap described great willowherb (Epilobium The MPI Incursion Investigators received has a phenome attractive to male fruit hirsutum) growing in the Travis wetlands 489 plant and environment notifications flies. The fly was identified by a PHEL reserve, in the northern suburbs of during the 3-month period January to entomologist and validated by PCR test. Christchurch. Great willowherb was first March 2019 (Figure 1), a 10 percent A response was initiated to establish recorded in New Zealand in 2018 when increase compared with the same quarter whether the fly was part of a breeding the invasive weed was found growing in in 2018 (444). Investigators immediately population. Investigations involving Waimakariri District, North Canterbury. stood down 100 notifications where the fruit flies of economic significance are This notification was referred to the presence of biological risk was ruled immediately transferred to the Response Response Group to be managed with out. Compared to the same period Group and managed by MPI’s response the earlier detection by MPI’s response in 2018, 114 more cases were further management process. management process. investigated to mitigate the biological A single QFF was found in a surveillance risk. The complexity and biosecurity risk trap at a residential property in Low-level GM sweetcorn seed associated with some notifications meant Northcote, Auckland. Management of contamination, Gisborne that some responses were transferred to this incident was combined with the A large-scale producer of corn products MPI’s Response Group which, with the response activated for the B. tryoni for human consumption contacted MPI assistance of the IIs and PHEL, conducts caught in Devonport. following a positive test for genetically responses to eliminate, reduce or contain modified (GM) constructs in powder the threats and potential impacts of In a third case, the duty Incursion manufactured from sweetcorn grown in biosecurity incidents. Investigator was notified by a PHEL Gisborne from seed imported from the entomologist that a single male tephritid US. Although further testing indicated a very low level of contamination, Plant health and environment notifications and outcomes for January – March 2018/19 600 below the maximum level of 0.1 percent stipulated in MPI import requirements, 489 500 the investigation was referred to the 444 Response Group to manage any public 400 communication. A response was not 340 initiated because the biological issue 300 was determined to be negligible to low risk as the level of the contamination 226 213 200 200 detected was < 0.1 percent. The seed had 132 been certified as GM-free by the supplier 100 100 87 75 and had undergone the relevant testing 49 25 18 before it was imported. New Zealand has Number of notifications, investigations and outcomes 18 5 2 15 1 0 zero tolerance for genetically modified Notifications Stood down Reirected Investigations Positive Response Negative Inconclusive Active organisms (GMOs) outside containment Notifications 2019 2018 Investigations without Environmental Protection Authority (EPA) approval. Figure 1: Plant health notifications and investigations and outcomes managed by Incursion Investigators, January to March, 2018 and 2019 24 Surveillance 46 (2) 2019 Unwanted organisms and the company from the seed exporter. The seed was collected by Interwaste (an regulated pests approved MPI contractor) and securely Low-level GM soybean seed transported to the Interwaste treatment contamination, Hawke’s Bay plant in Wellington for destruction by Another case of low-level GM seed steam sterilisation, followed by deep contamination (again below permissible burial. The process was supervised by levels) was reported in soybeans grown an MPI QO to certify that no spillage in Hawke’s Bay. Unlike the previous GM took place and the seed was handled case, this incident was managed by the securely. The MPI Plant Imports team Incursion Investigation team. It was was notified for awareness and possible auditing of the import process. Based on reported during the Christmas break, Figure 2: Poplar sawfly Cladius( grandis) larvae when many MPI staff were on leave. An the numbers provided by the importer, feeding on a poplar tree leaf, Dunedin (Photo: Incursion Investigator is on duty every the contamination level of GM found SIIPH) day from 8.30 am to 9.00 pm to manage was below the maximum of 0.1 percent the exotic pest and disease hotline stipulated in MPI import requirements. (0800 80 99 66). In this instance, the New to New Zealand sawfly, II with the co-operation of the grower, an MPI Quarantine Officer (QO) and Dunedin PHEL enabled the biosecurity issue to be A sawfly larva was found in a gypsy moth promptly mitigated. surveillance trap placed on a poplar tree in Abbotsford, Dunedin. Using molecular In this case a contract grower for a large methods the larva was identified by frozen vegetable company planted a PHEL as the poplar sawfly, Cladius 10-hectare block of edible soybeans/ grandis (Hymenoptera: Tenthredinidae), edamame (Glycine max) at his Hastings a species widely distributed in Europe, property. The crop had inconsistent Asia and North America. It is not known Figure 3: Adult poplar sawfly reared at PHEL, growth and before flowering was sprayed to cause significant damage every year Christchurch (Photo: PHEL) off with glyphosate (Roundup). Some but sporadic population booms have plants survived the herbicide application, been reported that result in significant When a risk assessment of the sawfly’s causing the grower and the company’s defoliation in the US and Canada. A impact was completed it was agreed by field manager to suspect GM Roundup- site inspection was conducted by the all that it was a low-impact pest and resistant seed. Samples of healthy and II, an SPS Biosecurity contractor and unlikely to be a significant biosecurity dead plants and seeds were provided for the gypsy moth trap inspector. Larvae concern to New Zealand. Following an diagnostic tests to determine whether were found on two poplar trees at the MPI media release about the new sawfly the seeds were GM. The suspected plants original detection site and a delimitation a resident of Mosgiel contacted MPI and in the field were removed mechanically survey was initiated the same day. In provided photos taken in December 2017 and about 50 kg of plant material was total, 11 sites were visited up to about of poplar sawfly larvae feeding on poplar deeply buried on the property by the 20 km inland from the detection site. leaves at her property. This indicated field manager under the guidance of At almost all sites larvae were found on that the species had already been in the an II. Samples of the plant DNA and leaves (Figure 2) or there was chewing country for at least a year without reports unused seeds were sent to an accredited damage consistent with the poplar sawfly. of significant damage. MPI has now offshore lab for testing. The live plant Damage on the worst affected trees was produced a fact sheet on the sawfly that is material and seeds tested positive for the patchy and restricted to the end branches, available on its website, and will continue 34S promoter, the 35S promoter and the presumably because the younger leaves to monitor the sawfly’s distribution EPSPS GM event, indicating that some were more palatable. Defoliation damage through the High Risk Site Surveillance of the seeds were genetically modified for was not obvious from a distance and was programme. Detections outside the herbicide resistance. more noticeable when standing under the Dunedin and Mosgiel area should be The website of the exporting company tree and looking up into the canopy. reported to MPI via the exotic pest and stated that it does not grow GM seed. The The survey did not find any adult disease hotline. New Zealand company had imported sawflies. However, larvae collected were 2,040 kg of soybean seed in September sent to PHEL (Christchurch), where the New to New Zealand ambrosia 2018. The import documentation said team successfully reared the first and beetle that the seed had been tested before only adult sawfly (Figure 3) seen by During the High Risk Site Surveillance arrival and was negative for GM those working on this investigation. The programme inspections this quarter, constructs.