Crop protection commercial biological control systems in the australian macadamia industry - richard llewellyn
Commercial Biological Control in the Australian Macadamia Industry Richard Llewellyn BioResources Pty Ltd www.bioresources.com.au
• Biological control is generally recognised as the best option for pest control - If its available.• Establishing if an organism is available, suitable, mass rearable and practical to use in the field is another story. A lot of criteria need to be met before it becomes a reality.• As commercial producers of biocontrol agents we build on previous work by researchers but invariably have to do a lot of new work on the mass rearing side.• It can be a complex process and every biocontrol project I have been involved in has gone in directions we could not have initially predicted.• Underlining our efforts is an understanding that there are many biological interactions going on in the field and if we can find out more about them we may be able to use them to our advantage in our production systems.
Trichogrammatoidea cryptophlebiae dubbed “MacTrix”Biological control of macadamia nutborer Tiny wasp only 0.5 mm long
•A good example is the tiny Trichogramma wasp for control of the major pest macadamia nutborer.•We first started mass rearing work in 1998 after finding some parasitised nutborer eggs in a crop near Lismore.•The wasp turned out to be Trichogrammatoidea cryptophlebiae which we have dubbed MacTrix.•The NSW DPI had a culture of nutborer so we were able to start a small lab culture of the wasp.•BioResources had experience with Trichogramma and was brought in to see if we could develop a mass rearing system.•We found that we could only rear the wasps on mac nutborer eggs and this meant we needed to have a very large moth colony.
• We were unsure if we could rear enough wasps to be useful on a commercial scale.• However, with lots of trial and error, an efficient system has evolved that includes a field release program of regular, relatively small numbers of wasps in the period leading up to and through the nutborer pressure period.• We are now treating around 5,000 hectares per season with a spill over so that much more crop area is benefiting from these releases.• The effectiveness of this program has exceeded our expectations.• Its has had district wide benefits – the wasps disperse into surrounding non-crop areas where nutborer breed resulting in much lower nutborer pressure in most areas and much reduced spraying and the associated problems during a wet season….• Without the yearly releases of the wasp MNB would soon resume its old major pest status.
MacTrix are applied early via cards that are stapled in trees along boundaries and in historical hot spots.
The nutborer project was successful for various reasons: • Firstly, MacTrix is a great biocontrol agent capable of very high levels of control. • Financial Support from Mac Society in early years – pretty modest but was enough to get it going. • Good collaboration between a local biocontrol producer (BioResources) and govt dept researchers. • Crop consultants were brought in during the research phase and were supplied with wasps for trial plots. • Research phase was also an educational phase. We had to develop practical system including fitting in with other management practices. • Consultants learnt how to monitor for wasp activity and could see that wasps were doing a good job so were able to pass on their confidence to growers who then readily adopted the new technology.
Bio Control of fruitspotting bugs?• Success with MacTrix and its area wide benefits led to pressure to develop biocontrol for the other big pest – fruitspotting bug.• Previous research had identified a number of parasitoids of FSB and some glasshouse trial work looked promising.• In March 2010 we set up a Voluntary Contributor (VC) project with 50 growers and BioResources. Started a FSB culture and began to investigate the biocontrol options.• Started looking in my semi-rural back yard and found Anastatus as well as Gryon in a friends suburban Brisbane backyard. So, these things are out there, we just have to give them a help along!• However, rearing spotting bugs in large quantities proved to be very difficult and inefficient. We had to find a better way.• Led to importation of a sample of unviable silkworm eggs from China… Immediate success in getting wasps to full development in silkworm eggs!
• Straight off to China in May 2011 to establish collaboration with Chinese researchers and secure a supply of SW eggs.• Imported a much larger amount of eggs in April 2012.• Developed mass rearing system and now begun field trials at 25 sites using similar model established with MacTrix – a local commercial partner, researchers, consultants and grower collaboration.• Wasps are being released along boundaries of crops and in likely bug breeding areas.• Means the assessment of effectiveness of parasitoids for spotting bug is problematic. A lot of the bug breeding happens outside the crop so unable to collect bug eggs etc.• Assessment can only be indirect with a longitudinal study to track changes in bug pressure and damage over several seasons.
Wasps are released via cards hung in trees along the boundary and in bug breeding areas on property and in adjacent farms
To sum up• We’ve had great success with MacTrix and hope to repeat it with Anastatus. However, it’s much more challenging project and will take more time. It wouldn’t be possible without the significant support of AMS, Avocado Aust, NSW Agric & HAL• We see beneficial insects as an indispensible component in a sustainable cropping system. New chemistry will be useful but expensive and will need to be accompanied by good biological control to produce the goods.• We want growers to be able to change the question they ask, from: Can I risk not spraying my crop? to: Should I spray and risk disrupting all the good biocontrol I have going in my crop?
The fruit spotting bug project is a collaboration of industry, government and private enterprise. This project has been funded by HAL using the avocado, macadamia, papaya and lychee industry levies and matched funds from the Australian Government. NSWDepartment of Primary Industries (NSW DPI) and Queensland Department of Agriculture,Fisheries and Forestry (QDAFF) are also contributing in-kind funds to the project, and NSW DPI is managing the project on behalf of all partners. Other project partners include the University of Queensland and BioResources Pty Ltd. www.bioresources.com.au