Research conducted by Victoria University PhD graduand Joanne Wilson shines new light on a problem that costs the New
Zealand agricultural industry an estimated $40 million annually.
Blowfly strike (cutaneous myiasis) is a major problem in New Zealand with the main costs associated with prevention of
strike, these include labour costs for implementing management practises such as shearing, crutching and docking and the
purchase of insecticidal treatments for sheep.
Significant production losses also occur due to death, loss of wool quality and reductions in live weight and the
disease is also a major animal welfare issue. The development of resistance to insecticides by some blowfly species has
exacerbated the problem further by reducing the protection period that some treatments can provide sheep.
Wilson’s thesis entitled Aspects of Insecticide resistance in New Zealand strains of the sheep blowflies Lucilia cuprina
and Lucilia sericata, investigates the mechanisms leading to insecticide resistance in the two pests.
In 1990 Wilson was awarded a research fellowship by Young’s Animal Health Ltd to determine the level and distribution of
resistance to insecticides in blowflies causing strike on sheep, the project was initiated by AgResearch, where much of
the research was based. Wilson found resistance to be widespread throughout New Zealand in more than one species of
blowfly.
Once she had identified the problem she expanded the project and in 1992 began a part-time PhD at Victoria University to
investigate the biochemical mechanisms of insecticide resistance in blowflies. Wilson identified several mechanisms of
resistance suggesting the problem and its management were complex.
Wilson’s thesis investigated ways in which this knowledge could be used for a more effective control of this pest
species and her studies form a basis for addressing the problems of insecticide resistance in blowflies and will
underpin further work in this area.
The projects economic importance has been recognised and funded for a number of years by The Foundation of Research
Science and Technology. Wilson will be admitted to the Degree of Doctor of Philosophy at Victoria University's Science
Faculty graduation ceremony on Tuesday 18 April, at 6.15pm at the Michael Fowler Centre.