Integrated pest and disease management – phase 2 (AP15001)
What’s it all about?
This project follows on from initial levy-funded work that resulted in approval to import and release the Mastrus ridens wasp as a biocontrol agent against codling moth in apples, to supplement pheromone-mediated mating disruption of the moth. This second phase of the research is responsible for the release of Mastrus ridens into sites in Southern Queensland, New South Wales, South Australia, Tasmania and Victoria for study of the wasp’s dispersal, predation and hyper-parasitism.
The biocontrol wasp Mastrus ridens has now been released at a total of 13 sites and although it’s still early days, the results are encouraging. Low levels of parasitism were detected in the original Goulburn Valley release site. After releases at the two Stanthorpe sites there were no signs of codling moth infestation of fruit remaining on the trees.
At the Tasmanian release site the codling moth population was extremely low and damage was the lowest experienced by the grower since the orchard had converted to organic. Similar results were obtained in Batlow, NSW.
Results from the other releases will be available in time.
The team is continuing to test pesticides to find out which will be toxic to the beneficial wasp as well as target pests. There is considerable variation in how susceptible the wasp is to the various formulations, but results are still pending.
The team is also working on improved traps for the Mastrus wasp so that they can better detect populations, to see if the wasp has established in the release orchards or nearby.
- You can learn more about the project on the team’s ExtensionAus website, including a video showing the Mastrus wasp in action.
- Read about the research, see what the wasp looks like and meet lead researcher David Williams on page 11 of the NSW DPI publication Orchard plant protection guide for deciduous fruits in NSW 2018-19.
In May 2018, the project team carried out further field releases of Mastrus wasps, at two orchards in the Adelaide Hills region of South Australia – both with a history of codling moth infestation. About 20,000 wasps were released across the two sites. These latest releases add to 10 previous release events at sites in New South Wales (in Batlow, Orange and Young), in northern Victoria, in Grove, Tasmania, and in Stanthorpe, Queensland. There are further releases planned for southern Victoria.
Monitoring at the previous release sites has been continuing, with the researchers tracking the presence of adult Mastrus ridens, active moth larvae, and predation of codling moths.
As reported in the last edition of Hortlink, the project team has also been looking at how chemicals that are commonly used on-farm might affect Mastrus wasps, so growers are able to identify and use products that won’t affect the predator’s survival or fertility. Testing of fungicides began in mid-December 2017, with initial results suggesting no fungicides in the test group are directly toxic/lethal to the wasps. As noted in the last Hortlink, this work is ongoing, with results to be reported to industry as they become available.
At the time of last reporting, there had been 10 releases of wasps across sites in New South Wales (in Batlow, Orange and Young), in northern Victoria, in Grove, Tasmania, and in Stanthorpe, Queensland. The next lot of releases are set to take place in southern Victoria, and in South Australia, during autumn 2018.
In the meantime, the researchers are monitoring the presence of adult Mastrus ridens, and their predation of codling moths, at previous release sites. Empty cardboard bands were established in orchards in late January and early February 2018, to be collected in late autumn/early winter an examined for evidence of codling moth larvae, evidence of parasitism and active Mastrus larvae.
The project team is also focusing on laboratory testing of chemicals commonly used on-farm, so growers are able to identify and use products that won’t affect Mastrus ridens survival or fertility. Testing of fungicides began in mid-December 2017, with initial results suggesting no fungicides in the test group are directly toxic/lethal to the wasps. This work is ongoing, with results to be reported to industry as they become available.
Across April and May 2017, about 50,000 wasps were released across sites in New South Wales (in Batlow, Orange and Young) and in Grove, Tasmania. These field releases followed earlier ones in Stanthorpe, Queensland, and in northern Victoria.
Since the project began, there have been 10 releases.
The researchers continue to monitor the presence of adult Mastrus ridens, and predation of codling moth by the wasps at various sites.
The project is also investigating the toxicity of pesticides to the wasps in the lab, looking at the two pesticides most commonly used to control coddling moth – Avatar and Altacor – as well as new pesticide Cormoran.
So far results suggest…
- Avatar is highly toxic to Mastrus ridens, even at very low rates (0.25 times the registered field rate)
- Samurai is highly toxic at the registered field rate
- Altacor is not toxic at rates up to four times the registered field rate, but at 0.25 times the registered field rate it can still have negative, sub-lethal effects, impacting on the next generation of wasps
- Cormoran has little effect at the registered field rate, but becomes moderately and then highly toxic at higher levels.
Work with other products will continue as the lab population of the wasps is grown.
In late April 2017, the project saw the first release of Mastrus ridens at Batlow and Orange in New South Wales. About 20,000 wasps were released in each area. This follows earlier field releases in Stanthorpe, Queensland, and in northern Victoria. You can read about these in the previous edition of Hortlink (see update below).
To date, field releases of Mastrus ridens have occurred in two orchards in Stanthorpe, Queensland, and in two orchards in northern Victoria. Monitoring of the wasps’ activity and parasitism is continuing in these orchards. Mastrus ridens is known to seek out hibernating coddling-moth caterpillars, laying eggs in the cocoon. Upon hatching, the Mastrus ridens larvae feed on the caterpillars.
The project is also investigating the potential toxicity of pesticides to Mastrus ridens. Two pesticides commonly used to control codling moth – Avatar (300g/kg indoxacarb) and Altacor (360g/kg chlorantraniliprole) – and new pesticide Cormoran (80g/L acetamiprid + 100g/L novaluron) have so far been tested. Altacor and Cormoran appear to be harmless to the wasp at the registered application rates, though Avatar appears to be toxic. Studies continue, and testing of other products will take place as the population size of the Mastrus ridens laboratory colony grows.
So far, sentinel bands containing codling moth larvae have been established across the original release orchard from phase one of the project in an attempt to monitor Mastrus ridens activity, and two field releases have also occurred at orchards in the Stanthorpe area of Queensland. Work is ongoing.
This project is a strategic levy investment in the Hort Innovation Apple and Pear Fund