Biocontrol of combat clover root weevil – an example of ‘technology push’.
In 2006 AgResearch imported a parasitic wasp into New Zealand to provide a biological control for the clover root weevil and prevent pasture damage in areas where the weevil had become established. As the weevil spread to new areas of the country, it was important to promote this ‘technology’, of a parasitic wasp as an effective long-term biological control, to farmers who noticed weevil damage on their farms.
‘Technology push’, via communications to farm teams who were already aware of the issue, was the appropriate choice for encouraging farm teams who needed to adopt this simple, effective technology. The extension activities used in this case included:
- articles in rural newspapers and on rural TV to spread the word about the weevil, its impacts, and the wasp as a simple control technique
- factsheets about the weevil and the wasp as a control method which were shared with farmers by Extension Agents at Field Days, as well as being directly mailed out and made available online
- running seminars at Field Days, focusing on how the biocontrol worked, how best to release, and other mitigation methods to use in the meantime while the wasp was getting established and starting to take effect
- giving pottles of parasite-infected weevils to farmers attending Field Days, for release on their own farms.
‘Technology push’ as an extension approach worked well in this situation because:
- Farmers were already aware of the issue, through seeing damage on their clover pastures.
- The issue itself is relatively non-complex: weevils = lots of pasture damage, wasp + weevils = minimised pasture damage.
- Releasing the parasites on-farm was entirely compatible with existing farm systems, so no other significant changes were required to achieve those benefits.
- For farmers to successfully implement the technology they didn’t need to rely on specialist technical knowledge or other external influences – it was a simple as getting a sample of parasite-infected weevils and releasing them onto infected pastures.
- The on-farm impacts are easily observable: CRW on pasture = notched and yellowing (or dead) clover
- The on-farm benefits are easily observable: less CRW = more clover in pastures = better lamb growth rates.