Drive is under way to rid communities of wasps

Invasive “social” wasps are putting major pressure on New Zealand’s biodiversity and cost the economy an estimated $130 million a year, Radio NZ reminded us today.

That figure comes from a 2015 Department of Conservation study (HERE) which assessed the economic impact of German wasps and common wasps across industries, society and the natural environment in New Zealand.

The report said the biggest economic impacts were on farming, beekeeping, horticulture and forestry workers.

This assessment was based on a literature review. Information was collected from previous studies and from affected sectors in New Zealand to estimate the total costs of wasps, ie the costs that could be avoided and the opportunities that could be gained if wasps were not present in New Zealand.

New Zealand has some of the highest densities of German and common wasps in the world. Wasps have huge social and biological impacts; they are one of the most damaging invertebrate pests in New Zealand, harming our native birds and insects.

The DOC study found the major financial impact was on primary industries and the health sector and included:

  • more than $60 million a year in costs to pastoral farming from wasps disrupting bee pollination activities, reducing the amount of clover in pastures and increasing fertiliser costs.
  • almost $9 million a year cost to beekeepers from wasps attacking honey bees, robbing their honey and destroying hives.
  • wasp-related traffic accidents estimated to cost $1.4 million a year.
  • over $1 million each year spent on health costs from wasp stings.
  • on top of the direct costs, almost $60 million a year is lost in unrealised honey production from beech forest honeydew which is currently being monopolised by wasps. Honeydew is also a valuable energy source for kaka, tui and bellbirds.

Radio NZ today described the invasive common wasp (aka Vespula Vulgaris), the German wasp, and our three species of paper wasp as being among “our most-hated introduced pests”.

The Royal Society, the Department of Conservation and some local communities are dedicating time, money and energy into putting an end to their predatory behaviour, which affects birds, bats, bees and other insects.

Entomologist and author of The Vulgar Wasp Phil Lester has been talking with Simon Morton about New Zealand’s problem wasps and the latest ways of keeping them under control, which include insecticides and genetic manipulation.

You can listen here to the interview (duration15′ :02″)

Source: Radio NZ

Advertisements

Officials to take new approach to managing myrtle rust after it is found in South Island

The Ministry for Primary Industries and the Department of Conservation say the fight against the plant disease myrtle rust is changing gear, given the prevalence of the disease across susceptible parts of New Zealand.

Myrtle rust has now been confirmed in the Tasman region at the top of the South Island, which means the disease has been found across almost all regions identified as most vulnerable based on habitat suitability and wind patterns.

“When myrtle rust was first discovered on mainland New Zealand in May last year, we said it would be a challenging disease to contain and eradicate but we would give it a good crack,” says the ministry’s myrtle rust response spokesperson, Dr Catherine Duthie.

“There has been an enormous operational effort over the past 11 months, but the windborne nature of the disease means that containment has not proved possible. We have signalled for a while the likely need to change gear from intensive surveillance and the removal and destruction of host plants to one where we look to manage the disease over the long term.”

The fungus has been found in Tasman region on ramarama (Lophomyrtus) on a residential property in Collingwood in Golden Bay and a commercial property at Pohara.

Moreover, the ministry has confirmed infections on five properties at Omori on the south-western edge of Lake Taupō, which is also a new region for infection.

“We now have well over 540 infected sites across the North Island and now the top of the South,” says Dr Duthie. “Because of the windborne, pernicious nature of the disease, we have to anticipate that there are likely to be many more infected sites beyond these.”

Dr Duthie says the focus of efforts now had to be placed on a science programme designed to lift our understanding around the disease such as ways to treat myrtle rust, resistance and susceptibility, and to improve seed banking collection.

“A second key focus has to be on working with communities across New Zealand to support regional efforts to combat myrtle rust.

“As we transition to long-term management, MPI and the Department of Conservation (DOC) will be engaging with iwi and hapū, territorial authorities, the plant and nursery industries, and communities to support the development of regional programmes.

“This could include regional surveillance programmes, identification and protection strategies for taonga plants and special locations, advice to landowners, seed banking, and broad community engagement.”

As part of involving and informing communities at the grassroots, the ministry and DOC will hold meetings with iwi and councils in affected regions over the coming months.

“We think this regional and community effort is really important.

“One of the most critical things is for people to continue to report suspected infections. We need to keep tracking the spread of the disease so we can better understand how it might behave in New Zealand and what its long-term impacts might be.

“This will help us to understand resistance of native species and will be vital to our myrtle rust science programme.”

More than 540 properties are known to have been infected by the fungal disease since it was first detected on mainland New Zealand in mid-May 2017. Since then, more than 5,000 myrtle plants have been securely removed and destroyed, and more than 95,000 myrtle plants inspected.

Members of the public are encouraged to continue to report any possible cases to the biosecurity hotline – 0800 80 99 66.

DOC will continue to focus on seed collection to secure the long-term future of native myrtle plants and monitoring biodiversity impacts to inform science and management actions. It will also continue efforts to protect sites of high ecological and cultural significance.

Distribution of detections

At 6 April 2018, myrtle rust has been detected on 547 properties across nine regions: Northland (4 properties), Auckland (82), Waikato (61), Bay of Plenty (123), Taupō (5), Taranaki (233), Manawatu (3), Wellington (34), Tasman (2).

Response facts and figures

Since myrtle rust was first detected on mainland New Zealand, officials have:

  • inspected more than 95,276 myrtle plants across the high-risk areas of the North Island and upper South Island
  • co-ordinated field activities of 7 surveillance teams and 4 plant removal teams
  • dedicated more than 104,000 hours to respond to the myrtle rust threat
  • found myrtle rust on an average of 45 properties each month (ranging from 2 in October 2017, to 184 in March 2018)
  • removed and securely destroyed more than 5,000 infected myrtle plants
  • undertaken approximately 330 laboratory tests of myrtle plant samples
  • received more than 3,300 calls from members of the public regarding suspected myrtle rust infections
  • with the Māori Biosecurity Network, held hui around the North Island to share knowledge of myrtle rust and provided surveillance training to more than 100 people on marae so they could monitor taonga myrtle plants
  • worked in partnership with iwi kaitiaki, councils, and community volunteers to establish a community-driven surveillance programme on Mauao (Mt Maunganui) historic reserve.

Source” Ministry for Primary Industries

Endangered beetle faces ‘unholy alliance’ of rabbits and redbacks

An “unholy alliance” between rabbits and Australian redback spiders is threatening the existence of an endangered New Zealand species, a study led by AgResearch has shown.

Carried out with the Department of Conservation (DOC) and University of Otago, the study has illustrated the struggle for the ongoing survival of the Cromwell chafer beetle – a nationally endangered native species that can now be found only in the 81 hectare Cromwell Chafer Beetle Nature Reserve between Cromwell and Bannockburn, in Central Otago.

The study found numerous rabbit holes that provided shelter for the rabbits were also proving ideal spaces for the redback spiders to establish their webs. Investigation of those webs in the rabbit holes found the Cromwell chafer beetle was the second-most commonly found prey of the spiders.

These findings “give a fascinating insight into the almost accidental relationships that can develop between species in the natural world, and how that can impact on other species,” says AgResearch Principal Scientist Dr Barbara Barratt.

As a result of the research, DOC has carried out a programme to break down old rabbit holes and hummocks in the reserve to destroy spider nests, and does regular rabbit control. An annual survey for beetle larvae with AgResearch will show whether these actions are having an effect.

Beetle larvae will be surveyed next summer to see what effect reducing redback spider nests is having on the Cromwell chafer beetle.

The Cromwell chafer beetle (Prodontria lewisi) is a large flightless beetle that lives underground in the sandy soils of the Cromwell river terrace. In spring and summer adult beetles emerge from the ground at night to feed on plants and to breed.

Radio NZ reports on biocontrol and the fight to eradicate bad weeds

Radio NZ has been reporting on the problem of weeds, both in native vegetation and on farms and orchards, and on the the Department of Conservation’s War on Weeds.

One interviewee was Hugh Gourlay, from Landcare Research, who discussed (here) his work as part of a team that works to find biocontrol agents to kill or knock back the worst weeds.

The work involves visiting the country of origin of a plant and hunting for diseases that infect it. The team is  also looking for insects that attack and eat any part of the weed, including the seeds, flowers, leaves or stems.

Hugh told Radio NZ it is sometimes possible to “knock a plant invasion on the head” with prompt action to hunt down and kill all the plants. Chemical control, using herbicides, is usually the next step, but at best it will “keep the problem at bay.” This leaves biocontrol as the best answer for widespread weeds.

Once potential biocontrol agents are identified they are imported into New Zealand and kept in strict quarantine, so they can be tested to see if they attack any plants other than the weed. “If they don’t attack anything else then we can look to release them.”

Describing some great biocontrol successes in New Zealand, Hugh cites St Johns Wort control in the 1960s as a “guiding light” success story. Ragwort (Jacobaea vulgaris), some thistle species and mist flower (Ageratina riparia) have had successful biocontrol agents introduced.

More recently, the broom gall mite and several species of beetle that attack Tradescantia have been showing great promise.

Darwin’s barberry is among Hugh’s recent projects.

“Darwin’s barberry continues to advance across the countryside in Otago and Southland. It takes over entire hillsides, and becomes quite a monoculture.”

Beginning in the early 2000s, the biocontrol team identified a seed weevil and a flower weevil in the plant’s native range in South America. The focus has been on the seed weevils, which have been released over two years.

Radio NZ’s “Our Changing World” recently featured a story about the wasp mite that is being investigated as a potential wasp biocontrol agent. It has also looked at the buddleia leaf weevil.

Biosecurity warning sounded: new pastures may create future weed threat

Breeding new fast-growing grass varieties that produce more seeds and are resistant to drought, pests, grazing and disease may inadvertently be creating the next generation of invasive weeds, an international team of researchers has warned.

As the global demand for dairy and beef escalates, farmers are increasingly seeking ways to reap greater productivity from their pastures.

The problem, according to Philip Hulme, Professor of Plant Biosecurity at Lincoln University and lead researcher at the Bio-Protection Research Centre, is that in making grass varieties more robust, they are more prone to becoming a problem for the environment.

The researchers have made four biosecurity recommendations for government, industry and researchers.

Continue reading

Challenge boosts protection of biological heritage

The National Science Challenge, New Zealand’s Biological Heritage Nga Koiora Tuku Iho, is to receive funding of $25.8 million over five years for research to protect and manage the country’s biodiversity, improve biosecurity and enhance resilience to harmful organisms.

Science and Innovation Minister Steven Joyce says the Challenge spans a wide range of scientific disciplines and will include researchers from nearly all New Zealand’s relevant research institutions.

The Challenge will be hosted by the Crown research institute Landcare Research. It includes researchers from the other six Crown research institutes and all eight New Zealand universities.

It also draws on research expertise of Te Papa Tongarewa, the Department of Conservation, the Ministry for Primary Industries, regional councils and Ngāi Tahu.

Continue reading