APP203853 Giant Willow Aphid BCA Submissions

APP203853 Giant willow aphid BCA Submissions

17 September 2019

Under section 34 of the Hazardous Substances and New Organisms Act 1996 Volume 2 of 3

To import and release of the parasitoid wasp, Pauesia nigrovaria, as a biological control agent for the pest, the giant willow aphid (Tuberolachnus salignus)

Submission Number Submitter Submitter Organisation

SUBMISSION127616 Jenny Dymock Northland Regional Council

SUBMISSION127617 Ed Hills

SUBMISSION127618 Stephen Millichamp

SUBMISSION127619 Peter Marshall Hackfalls Arboretum

SUBMISSION127620 Juliet Ryan

SUBMISSION127621 Graham Milligan Milligan Seeds

SUBMISSION127622 Eric Cairns

SUBMISSION127623 Ricki Leahy Trees and Bees Ltd

SUBMISSION127624 Brian Monahan Integrated At

SUBMISSION127625 Gregory Kent NZ Farm Forestry Assn - SUBMISSION127626 John McLean Gisborne-East Coast Branch SUBMISSION127627 Rob Tapert GHP NZ Farm Forestry SUBMISSION127628 Bruce Bulloch Association - National Office SUBMISSION127629 Kathryn Hurr

SUBMISSION127630 Steve Cave Hastings District Council Foundation for Arable SUBMISSION127631 Abie Horrocks Research SUBMISSION127632 Martin Craig NZ Plant Producers Inc

1 SUBMISSION 127616 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 17

Dr J J Dymock, Northland Regional Council (Jennifer Dymock) 36 Water Street Whangārei 0110 Northland New Zealand Ph: (09)4060033 [email protected] Submitter Type: Not specified Source: Email Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes See supporting document attached

Subject: GIANT WILLOW APHID

Report prepared by: Dr J Dymock and staff of Northland Regional Council.

Introduction

The Giant Willow Aphid (GWA), Tuberolachnus salignus, was first reported to MPI on 24 December 2013, having been detected on a crack willow (Salix x fragilis) in Western Springs in Auckland. However, it was not until 8 January 2014 that a specimen was received by MPI and the identity of the aphid was confirmed on 13 January 2014. The aphid was declared an Unwanted Organism under the Biosecurity Act 1993. However, in Northland it was observed earlier, but not reported, in Mangawhai in October 2013 (Brian Hollis pers.comm.) and in Kohukohu, North Hokianga, in November 2013 (Ian McIvor Plant and Food Research report).

Since its discovery GWA has been reported from Northland, Auckland, Bay of Plenty, Taranaki, Gisborne, Hawke’s Bay, Wairarapa and Tasman District. It has been found as far south as Clyde in the Central Otago and Greymouth on the West Coast of the South Island. In Northland, GWA also has been recorded from Kawakawa, Kaikohe, and Oruaiti (Doubtless Bay) in the Far North.

Identifying features

Tuberolachnus salignus is a very large aphid with a body length of 5.0-5.8 mm. Wingless individuals are mid-brown to dark brown with several rows of black sclerotic patches. There is a large dark brown large thorn-like tubercle in the centre of the back (see photo). The antennae are less than half the body length. Winged individuals (alates) have the forewing membrane unpigmented but the wing markings and costal margin are dark brown. Waving a hand over an aphid colony prompts a collective lifting of the hind legs, and any physical disturbance of a colony results in rapid dispersal up and down the stem. Squashing a GWA releases a red bloody stain.

Photo: Stephen Thorpe

Life Cycle

GWA reproduces parthenogenically (reproduction without males) all year round and single aphids can therefore give rise to new populations. No males are known. The winged adults of GWA are highly mobile and like other aphids able to disperse over long distances in short periods of time.

Adults give birth to miniature adults called nymphs. Each adult alate (winged adult) produces 34.3 nymphs on average, each surviving nymph capable of doing the same at maturity (maturation times range from 12 to 17 days depending on temperature). The threshold temperature for development has been measured as 5.5 +/- 0.3 °C so it is expected that some development will continue over winter in Northland. Both adult forms continue to survive post-breeding.

The early season colonies appear in summer and are situated at the base of the willow trees, moving up the stems as numbers increase. During summer, colonies formed by alatae dispersing from other infestations start higher on the stem, some up to 3.5 m from the ground. By late summer colonies can contain tens of thousands of individuals.

Colonies in the UK persist through the autumn and, although they decline in late autumn, continue to feed on the stems after leaf fall and into late winter (February). Continuing growth and reproduction on leafless and dormant trees is unusual for aphids. How the aphids survive the winter is still unknown as an overwintering stage has not yet been identified. It may be that numbers of aphids surviving over the winter and into early spring are at undetectable low levels but these few aphids are able to found the subsequent year’s populations.

In their first season in New Zealand colony decline has happened rapidly with very few sightings of the aphid from the second week in April 2014. Wayne Teal (NRC) reported there had been a slight decline in numbers of aphids at the Mata nursery on 11 April. Clusters or colonies of aphids were smaller and individual sizes were smaller overall, but the GWA was still present. By Easter (18 April) they had disappeared. No aphids were found on 11 May by the author on a previously high population of GWA on crack willow at Kawakawa. The same behaviour has been observed in other regions in New Zealand. The trigger for the disappearance does not seem to be temperature as mild temperatures are still persisting in Northland in May.

Willows as a resource

Benefits In New Zealand, willows are used for erosion control, shelter belts and sometimes as fodder for livestock. Willows are probably one of the most important sources of pollen and nectar for bees during the spring period when hive numbers need to increase in preparation for summer pollination services. Many other pollinators which contribute to pollination of crop also use willow pollen and nectar. Willows are also used as amenity trees and may become useful in the future as a source of bioenergy.

Weeds Some willow species, notably, crack willow (Salix fragilis), grey or pussy willow (Salix cinerea) and to a lesser extent weeping willow (Salix babylonica) are considered weeds. Willows need to be managed. They can block waterways, reducing the quality and flow of water, cause flooding and damage to nearby infrastructure. They can also reduce available habitat for wildlife and obstruct access to streams for fishing and aquatic sports.

Host plants for Giant willow aphid

Known feeding hosts of GWA are limited to willow (Salix spp.) and rarely, poplar (Populus spp.) species (family Salicaceae). GWA colonises most willow species but colonies grow faster on some willows than on others. It colonises both tree willows and non-tree willows (shrub and osier). The aphid has been reported overseas and in New Zealand on Salix alba, S. fragilis, S. cinerea, S. babylonica, S. viminalis (Kinuyanagi), S. schwerinii, S. miyabeana, S. matsudana and their hybrids amongst others. People may observe the aphid on other plant species; this is a result of aphids either being blown from adjacent host plants or winged (alate) aphids alighting on plants after periods of flight. This is a passive process on the part of the aphid as they do not have a choice as to where they land following dispersal.

MPI is aware that there have been unconfirmed reports of GWA on kiwifruit in New Zealand however there are no records of kiwifruit as a feeding host. Aphids when they alight on plants will not begin feeding unless the plant they have landed on is a host plant, though they may undertake exploratory probing. It is not uncommon to find large numbers of aphids on plants other than their hosts as well as other structures.

Damage

Tuberolachnus salignus has an adverse impact on the growth of the host trees and should be considered as a potential pest of willows used for soil conservation or as a production crop. Tree death has not been observed in Short Rotation Coppice (SRC) willows, but direct responses to aphid infestation have been measured. These include: 1) increase in photosynthetic rate, 2) increase in leaf nitrogen, 3) increase in tree water use, 4) reduction in shoot and root biomass, 5) reduction in growth in the following year. The increase in tree water use in response to aphid colonisation may exacerbate the effects of summer drought stress of the trees.

Large amounts of honeydew secreted by the aphids encourage the growth of sooty mould on willow stems and attract wasps and ants, though bees are reported to be infrequent feeders. There have been reports of unusually high numbers of wasps throughout New Zealand this summer which may have resulted from the large amounts of honeydew produced by GWA. Honeydew is sugar that is not reaching the roots which reduces the capacity of the tree to absorb water and nutrients. Deposition of sugar on to the ground has been shown to induce tree branching in SRC willow. Wasps are indicators of GWA infestation, as are blackened (mould covered) willow stems and sticky wet patches under willow trees and on understory vegetation.

Giant willow aphid colony on willow stem. Photo: Wayne Teal, NRC

Willow stems blackened with sooty mould. Photo J J Dymock

If aphids are feeding on host plants grown as shelter belts there is the potential for the associated sooty mould to come into contact with commercial crops. GWA is found in most countries New Zealand exports to and is not considered a quarantine pest. Its presence on export crops is not likely to affect market access.

There has been reported contamination of rainfall water tanks in Mangawhai, Northland (Brian Hollis pers.comm.). The owner was advised to prune overhanging branches or remove trees in the vicinity of the roof collection system. This is the most effective means of preventing contamination of the water supply from the aphids themselves or the honey dew they secrete, rather than risk insecticide contamination of the water supply.

Control options

Chemical control Systemic insecticides that are friendly to bees provide the best chemical control approach. It may be difficult to effectively use contact insecticides from a boom. Aphids are also likely to reinvade chemically treated areas later in the season, or in the following year.

Biological control agents Colony reduction by ladybirds (adults and larvae) and lacewings is low, possibly because they taste strongly of salicin and tannins. Some colonies overseas have been decimated by a pathogenic fungus that attacks the aphid internally, but the identity and ecology of the pathogen is not yet known. Presence of ‘mini-raisin-like hanging by stylet’ aphid individuals usually indicates the presence of this fungus that can sweep through populations, killing them quickly.

No parasitoid of GWA has been recorded in Europe. In Japan, Tuberolachnus salignus is parasitized by the braconid wasp, Aphidius salignae, and by a specific hyperparasitoid, Pauesia salignae. In Northland, the 11-spotted ladybird, Coccinella undecimpunctata, has been observed feeding on GWA (Wayne Teal pers.comm. and photo).

Ladybird feeding on giant willow aphid. Photo: Wayne Teal, NRC

At a local, regional and national scale eradication is not feasible, and given the aphids well known ability to disperse on wind currents containment is not an option either. Further complicating the picture is the fact that this aphid does not produce males and therefore a single nymph can give rise to populations in short periods of time.

There may be an opportunity to breed willows for resistance to GWA.

Current status of giant willow aphid in New Zealand

On 14 February 2014, based upon the aphid’s known distribution and biology, and the likelihood that the aphid was widely distributed, MPI concluded that eradication was not feasible. Neither was a programme to control the spread feasible. The Ministry considered that the most effective management option is for those landowners and managers who have concerns about the effect the aphid may have on their host plants to manage the aphid as part of their normal pest management operations. As part of the process of standing down this response MPI removed the Unwanted Organism status of this species.

Specific issues relating to Flyger Road Poplar and Willow Nursery

GWA was first observed at the Flyger Road Nursery on the 30 January 2014 and consideration was given to controlling the outbreak using an insecticide. However due to the close proximity of waterways and the risk of stream contamination spraying of the recommended insecticide was not undertaken. Although the population of aphids at the time appeared very high and some damage was expected, only a slight reduction in tree growth rate has been observed and poplar stools in the nursery remain largely unaffected.

In early April it was noted that GWA was in decline and was all but gone from the nursery by 17 April. GWA has likely entered a wintering stage and is expected to re-emerge during spring and summer.

The longterm impact of GWA on the Flyger Road nursery is difficult to quantify and control options are limited. The emergence of aphids will be monitored leading into summer and use of alternative insecticides will be reconsidered should their impact on willow and poplar stock appear significant.

SUMMARY Measures to reduce risk of spread of GWA are no longer feasible as the aphid is now probably established throughout Northland. Insecticide control of GWA is ineffective over a large area due to re-infestation by aphids which disperse rapidly. New populations can start from a single individual. GWA are at present undetectable on willows and this is expected to continue through winter and spring. Populations will be monitored to measure the build-up in numbers next summer. GWA is unlikely to kill willow but infestations will compromise growth and have other downstream affects such as increased wasp numbers. The aphids will also be surveyed to determine whether the fungus which results in population crashes in the UK is present in New Zealand. Other control options could include investigating a parasitoid wasp from Japan and supporting a breeding programme for resistance to aphid attack.

Thanks to Ian McIvor (Plant and Food Research) and Wayne Teal (NRC) for information provided.

SUBMISSION 127617 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 3

Ed Hills,

Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes I have followed the research on this parasitoid wasp by SCION and I am satisfied it is the right insect to control GWA in New Zealand.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes The Poverty Bay- East Coast Region has relied on substantial plantings of willows for erosion treatment and protection in the past and more recently for Spring forage for bees. A number of young and older willows have been affected by the giant willow aphid (GWA) causing slower growth and in severe cases, death of the trees. Within this region a large riparian planting project is planned for the Waiapu River and to obtain the best early protection, willows have to be included in the planting inventory. A range of shrub and tree willow clones need to be considered. Some of these clones are susceptible to GWA and are unable to thrive when attacked by this parasite. Control of this aphid through the release of the parasitoid wasp Pauesia nigrovaria will make it possible to include these susceptible clones in stock proof, riparian riverbank as well as hill country treatment areas. The region hosts a large apiculture industry. Sugars in the honey dew from GWA is causing crystallization in the honey, limiting production and downgrading affected honey. It also attracts large numbers of wasps which in turn attack hives. Reducing the GWA population by using Pauesia nigrovaria, will significantly benefit this industry. Climate change predictions indicate drier Summers for this Eastern region requiring pastoral farmers to further mitigate against drought conditions. A high producing forage shrub willow Salix schwerinii (kinnyanagi), once promoted as a reliable Summer supplementary feed, fell out of favour with pastoral farmers due to its susceptibility to GWA. The release of Pauesia nigrovaria will over time, allow this willow to regain importance as a reliable forage willow for drought prone areas of New Zealand. GWA is currently under attack by the harlequin ladybird which does not predate on the aphid in the same manner as the parasitoid wasp. Populations of this ladybird are increasing across the North Island fuelled by a healthy diet of GWA. Large numbers are already causing tainting problems in the wine industry. Pauesia nigrovaria will not cause the same problems as the harlequin ladybird, however, by reducing GWA numbers it will help control this ladybird population. Pauesia nigrovaria is therefore the most effective and reliable biological control for GWA and I fully support its release into the New Zealand environment.

The submitter have elected to withhold their personal details from publication. SUBMISSION 127618 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 18

Stephen Millichamp 295 Winterslow Road RD 1 Ashburton Canterbury New Zealand Ph: 0274194477 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes I am a willow grower for making willow baskets and the giant willow aphid infests my willows leaving dirty sooty mould on the stems and weakening the stems, making them unsuitable for weaving into baskets. The Pauesia wasp would help reduce the aphids on my willow, minimising damage and allow me to produce a product with little use of sprays making them more marketable to the public.

Submission Reference no: 19 above, Hackfalls Arboretum (Peter Marshall) Tiniroto via Gisborne Poverty Bay New Zealand Ph: 61 248 422677 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes We have observed damage to the point of fatality of old and young willows Extremely worried that we will lose the environmental services ( stabilisation , streambank repair ) provided by willows All in favour of biological control of Willow Aphid Regards PM

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Fear that willows will be removed from the landscape and erosion will increase dramatically

Submission Reference no: 20

Julie Ryan, Juliet Christina Ryan 264 Kepa Rd Mission Bay New Zealand Ph: 095780498 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes The death of willows in Northland was very noticeable last year. I travel from Auckland to Kaitaia often.

Submission Reference no: 22

Graham Milligan, Milligan Seeds (Graham and Heather Milligan) 4 Level St, Dipton Southland New Zealand Ph: 0274880870 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes As below

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes As below

Clause All submissions are taken into account by the decision makers. In addition, please indicate whether or not you also wish to speak at a hearing if one is held. Position No I do not wish to speak about my submission at the hearing Notes As a grower of a wide variety of willows for shelter, erosion control and twisted willow for the floral market in our nursery. We have the Giant Willow aphid which has created damage across many varieties. As farmers on the banks of the Oreti River, a notably braided river, willows are used extensively for river control. Damage to these willows will compromise the ability to effectively control the river flow. Graham SUBMISSION 127622 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 23

Eric Ramsay Cairns 178 Mangaroa Valley Road, RD1, Upper Hutt Wellington New Zealand Ph: 045267929 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Many willows are dying in our area. There is a substantial build up of harelquin ladybirds, which may or may not be a good thing. The proposed wasp species is highly specific, and should not affect other economic or native species. Bee keepers do not need another handicap such as GWA

Submission Reference no: 25

Ricki Leahy, Trees and Bees Ltd (Ricki Leahy) PO Box 9 Murchison Tasman New Zealand Ph: 021 523930 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes I am a beekeeper and am supportive of the Pauesia nigrovaria parasitoid wasp being used as a biological control for the Giant Willow Aphid. The 'honey' dew that derives from the aphid is as good as useless to the beekeeper as it is to the bees. It has a minimal nutritional value for the bees as well as goes rock hard in the honey frame and has a terrible taste that spoils other honey.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes As a beekeeper I am concerned of the damage the Giant Willow Aphid is doing to our willow trees . The willows are a very important spring time pollen and nectar source for the bees and in many instances is critical to the hive build up to become strong pollinating hives or as honey hives.

Submission Reference no: 26

Brian Monahan, Integrated At, LTD

Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I oppose the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes I am a forester and have planted large amounts of willow, poplar, and also cultivate honey... so I’m negatively effected by the aphid. However, we have seen multiple examples in history of how the introduction of new species have unintended consequences. I’m especially concerned about how wasps introduction could harm native insects. While risks exist either direction, precaution is prudent.

The submitter have elected to withhold their personal details from publication. SUBMISSION 127625 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 27

Gregory Kent 10 Atamira Close Wellington New Zealand Ph: 0220472973 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes I understand Pauesia has real potential to provide a long term and sustainable solution for controlling GWA, without the use of chemicals and so on that basis I strongly support the application. I also understand there may be a risk of GWA migrating to poplar trees which is an additional risk to our environment.

Submission Reference no: 28

Secretary, on behalf of the Executive, Gisborne-East Coast Branch, NZ Farm Forestry Association (John McLean) 20 Sterling Park, Lytton West Lytton West New Zealand Ph: 068686440 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes Unanimous support from 8 members of the executive.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Willows are a widely used species in the management of our pastoral lands in the Gisborne-East Coast area. They are particularly utilized in erodible areas where excess moisture threatens land stability. Willows are grown in many nurseries and recent heavy infestations of the Giant Willow Aphid (GWA) around the root collars of growing poles have compromised growth and caused excessive adventitious shoot development in the root collar area. Willows are renowned for the spring supply of pollen and nectar for bees. It is important to keep willows healthy. The large increase in GWA numbers in the autumn intercepts the nutrients from the senescing foliage. The sweet honeydew they produce is readily collected by bees (see Apiculture New Zealand submission for details of impact) and by the predatory wasps such as the German and Common wasps in the Vespulidae. The GWA honeydew splashes through the canopy and settles on leaves and branches that support black sooty mould. When willow trees are close to horticultural activities, fruits are degraded by such honeydew splash consequences. Willows that have been infested by GWA are readily recognized by their blackened stems and branches. It is to be hoped that the Pauesia nigrovaria parasitoid will significantly reduce these GWA impacts.

Submission Reference no: 29

Rob tapert, GHP (Rob Tapert)

Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Save our rivers

The submitter have elected to withhold their personal details from publication. SUBMISSION 127628 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 30

NZ Farm Forestry Association (Bruce Thomas Bulloch) 128 Cook Street New Zealand Ph: 063577338 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes I formerly worked at the Soil Conservation Centre in Palmerston north and am well aware of the many uses that can be made of willows in erosion control and farming.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Biological control is ultimately highly cost-effective and does not involve putting more chemicals out in the environment

Clause All submissions are taken into account by the decision makers. In addition, please indicate whether or not you also wish to speak at a hearing if one is held. Position No I do not wish to speak about my submission at the hearing Notes I would be available to assist the hearing if required but do not have anything more to say at this stage. SUBMISSION 127629 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 31

Kathryn Hurr 38 Waiuta Street, Titahi Bay Porirua New Zealand Ph: 02102978993 [email protected] Submitter Type: Not specified Source: Email Overall Position:

Clause What is your position on the application? Position I support the application Notes I support the application for the parasitoid wasp biological control for giant willow aphid. The expected benefits of releasing the parasitoid include increased health of trees used for erosion control and as spring resources for bees, improved health of honeybees and honey quality, reductions in harmful sooty mould in areas close to willows, and reduced populations of invasive pest insects such as vespid wasps, which are voracious predators of native and beneficial insects.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes As a member of the New Zealand Farm Forestry Association, I support the use of effective biological controls to manage insect pests of trees in the landscape.

Clause All submissions are taken into account by the decision makers. In addition, please indicate whether or not you also wish to speak at a hearing if one is held. Position No I do not wish to speak about my submission at the hearing Notes Management SUBMISSION 127629 of giant News willow aphid Photo: Bryce McQuillan ANNUAL NEWSLETTER ▪ JUNE

These assessments showed that P. nigrovaria Scion update paid little attention to the non- target species, Stephanie Sopow, Carl Wardhaugh and compared to GWA (Figure ). Antennal and Belinda Gresham, Scion ovipositor contact on the non-target species were significantly less, though one female Biological control update wasp did appear to oviposit in two cypress aphids. However, no progeny developed We have made great progress and achieved and subsequent dissections revealed no excellent results in our programme on the evidence of an egg or a larva. P. nigrovaria long-term management of the giant willow made no attempt to oviposit in the less aphid (GWA), Tuberolachnus salignus, which closely-related black peach aphid. has been causing widespread problems throughout New Zealand since it was first With both the host testing results and found here in . behavioural assessments indicating very Figure . Pauesia nigrovaria female probing a little or no risk to non-target species, we We have now completed host specificity GWA with its ovipositor. believe that Pauesia nigrovaria is safe to trials and behavioural tests examining how our release in New Zealand, and that its proposed biological control agent interacts Cinara fresai (Lachninae) was chosen as it introduction will be beneficial, leading to a with both GWA and other aphid species is in the same subfamily as GWA and comes reduction in the damaging effects of giant present in New Zealand. Based on the very closest to it in body size. The black peach willow aphids and the problems associated favourable results, we have prepared an aphid Brachycaudus persicae (Aphidinae: with their feeding activities. These include application to the Environmental Protection Macrosiphini) represents the largest group increased health of trees used for erosion Authority for its release. of aphids in New Zealand, and the three control, improved health of honeybees remaining species represent New Zealand’s and improved honey quality, reductions in Back in , we identified a promising three native aphid lineages: the Muehlen- harmful sooty mould and reduced populations biological control candidate for GWA: a beckia aphid Aphis cottieri (Aphidinae: of invasive pest insects such as vespid wasps Californian parasitoid wasp named Pauesia Aphidini), the tōtara aphid Neophyllaphis and harlequin ladybirds, both of which are nigrovaria (Figure ). This wasp is a highly- totarae (Neophyllaphinae) and the southern voracious predators of native and beneficial specific natural enemy of GWA in its native beech aphid Sensoriaphis nothofagi insects. environment, and in December we (Taiwanaphidinae). successfully brought a small number of these Applying to the Environmental Protection parasitoids into our containment facility at Results of the host testing trials were Authority to release Pauesia nigrovaria is Scion in Rotorua. excellent for all non-target aphid species, an in-depth process and we are seeking with zero parasitism recorded on any species beekeeper participation to support our In the following eighteen months we other than the target, GWA. In addition to proposal. You can make an online submission undertook host testing trials of Pauesia these trials, we also conducted behavioural at www.epa.govt.nz/public-consultations, nigrovaria against five non-target aphid assessments with Pauesia nigrovaria and or send a letter of support to us at Scion. If species, representing a range of aphid groups three aphid species: GWA, the closely-related approved, we expect the first releases of present in New Zealand. The cypress aphid cypress aphid and the black peach aphid. P. nigrovaria to occur in early .

Tuberolachnus salignus Cinara fresai Brachycaudus persicae

Mean frequency Mean Antennal Oviposition Oviposition No. of No. of wasps Antennal Oviposition Oviposition No. of No. of wasps contacts probes events mummies emerged contacts probes events mummies emerged Pauesia nigrovaria behaviour Pauesia nigrovaria behaviour

Figure . The mean frequency of observed behaviours (antennal contacts, ovipositor probes, and oviposition) by Pauesia nigrovaria towards GWA (orange), the cypress aphid (left, blue), and the black peach aphid (right, green), as well as the number of parasitized mummies produced and the number of wasps that eventually emerged (zero for both non-target species). SUBMISSION 127629

S. candida * Plant & Food S. eriocephala S. lasiolepis Research update S. lasiolepis x viminalis Trevor Jones, Plant & Food Research S. purpurea S. schwerinii Aphids S. viminalis * No aphids Willow growth trial update S. x reichardtii * P < . S. alba A nursery field trial at Massey University has S. lasiandra looked at the effect of the GWA on young S. matsudana * S. matsudana x alba willow trees propagated from cuttings. * S. matsudana x alba * S. matsudana x lasiandra * During the first growing season (-), S. x fragilis the aphids had no effect on the survival and growth of the willow trees. However, in Height growth (cm) the second growing season (-), the aphids had a noticeable effect with a Figure . The height growth of the willows during the second growth season from - . reduction in the survival and growth of susceptible willows (Figures and ). ‘Booth’, the tree survival was %, but The GWA-resistant S. lasiolepis x viminalis there were reductions in height growth of is a shrub willow that has recently been Tree survival was % and % for Salix % to %. released to regional council nurseries. It is an candida and S. viminalis, with reductions in early-flowering male clone, with potential height growth of % and % respectively. In the GWA-resistant willows S. eriocephala, for beekeepers, and has shown good drought S. lasiolepis and S. lasiolepis x viminalis, tolerance and height growth. For the commercial willows S. matsudana, the aphids had no effect on tree survival, S. matsudana x alba ‘Moutere’ and ‘Tangoio’, and the reductions in height growth were S. schwerinii ‘Kinuyanagi’, and S. purpurea less than %.

Figure . Salix viminalis trees with aphids (left row) and without aphids (right row) in June .

‘Management of giant willow aphid’ is a Ministry for Primary Industries Sustainable Farming Fund project. This work was supported by regional councils and:

For more information contact Stephanie Sopow, Project Leader, at [email protected] www.giantwillowaphid.co.nz SUBMISSION 127630 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 32

Steve Cave, Hastings District Council (Steve Cave)

Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes Application is supported on the understanding Scion are taking all practical steps to manage the biological agent for its intended purpose and minimise / eliminate any potential risk of the biological control agent having undesirable or unwanted impacts on New Zealands flora, fauna, agricultural and horticultural environments and industries.

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Local authority

The submitter have elected to withhold their personal details from publication. SUBMISSION 127631 APP203853 Giant willow aphid Biological Control Agent

Submission Reference no: 33

Abie Horrocks (Abie Horrocks) Foundation for Arable Research PO Box 23133 Templeton Canterbury New Zealand Ph: 0272499286 [email protected] Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes Biological control is an important component of integrated pest management. Introducing the parasitoid will support a range of environmental functions such as reducing the use of broad spectrum insecticides. It is important that the willows do not die as currently they are serving a crucial role of stream bed stability (managing waterway sediment load is a high priority for New Zealand).

Submission Reference no: 34

Martin Craig, NZ Plant Producers Incorporated (Martin Craig)

Submitter Type: Not specified Source: Web Form Overall Position:

Clause What is your position on the application? Position I support the application Notes

Clause The reasons for making my submissions are: (Any supporting documents can be attached at the end of this submission) Notes NZ Plant Producers Inc. represents approximately 100 businesses in commercial plant nurseries and related sectors such as plant retailers and landscape gardeners. We are supporting the importation and release of the parasitoid wasp, Pauesia nigrovaria, as a biological control agent for the pest, the giant willow aphid (Tuberolachnus salignus). Our members include nurseries producing willows, poplars, apples and pears, which are all at risk from giant willow aphid. It can also infest native tress including Coprosma spp. Apart from the direct effects on the host trees, the aphid produces an unsightly sooty mould which can reduce the commercial value of hosts and any plants nearby. Lastly, the aphid has deleterious effects on bees, which are an important pollinator for many plant species. We believe Pauesia has real potential to provide a long term and sustainable solution for controlling GWA, without the use of chemicals. The expected benefits of releasing the parasitoid include increased health of trees used for erosion control and as spring resources for bees, improved health of honeybees and honey quality, reductions in harmful sooty mould in areas close to willows, and reduced populations of invasive pest insects such as vespid wasps, which are voracious predators of native and beneficial insects.

Clause All submissions are taken into account by the decision makers. In addition, please indicate whether or not you also wish to speak at a hearing if one is held. Position Yes I wish to speak about my submission at the hearing Notes

The submitter have elected to withhold their personal details from publication.