APPLE and pear growers are one step closer to getting an insect ally to help defend against the dreaded codling moth.
The Department of Agriculture, Fisheries and Forestry (DAFF) has released a Draft Risk Analysis report for the release of the parasitoid wasp, Mastrus ridens for the biological of codling moth (Cydia Pomonella).
The codling moth has a savage impact on pear, apple and other fruit crops throughout Australia each year.
Its larvae bore into fruit after hatching, destroying internal flesh and providing a doorway to disease.
The Department of Primary Industries Victoria has led the charge on bringing the wasp to Australian shores, having conducted its own testing and trials for a number of years.
Now, it seems, every other state and territory has supported the move.
A preliminary draft of the report was distributed to state and territory departments of primary industry and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) through the Plant Health Committee (PHC) in January this year.
All comments endorsed the preliminary draft and its recommendations.
If the proposal gets the go-ahead, the wasp would be released, subject to standard quarantine conditions associated with the import and release of biological control agents.
Although Mastrus ridens might be the great-winged hope for pome fruit orchardists, the codling moth has been the target of several biological control programs in the past.
New Zealand allowed the release of the Mastrus ridens wasp in June last year. It has also been used effectively in America since 1998, Argentina since 2003 and Chile since 2006.
According to the Draft Risk Analysis: “All released insects are descended from one founding colony collected in Kazakhstan in 1994.”
“This lineage is also proposed as the source for the insects to be released in Australia.
“To date, no reports of significant off-target effects have been reported from any country in which this insect has been released.”
Stakeholders have until May 22 to provide written comments or submissions on the proposal.
Wasp nothing to “bee” worried about
Beekeepers need not be concerned over the release of the Mastrus ridens wasp - it’s not a host for Varroa mite.
Within the Draft Risk Analysis on the wasp, section 1.2.3 labeled “Contaminating pests” admits: “There are organisms that may arrive with imported biological control agents. These organisms may include parasitoids, mites or fungi.”
But a CSIRO ecosystems expert told Good Fruit and Vegetables magazine that Mastrus ridens is not a vector of Varroa mite.
Dr John Roberts, CSIRO Ecosystem Sciences said the destructive Varroa mite would not hitch a ride on the introduced wasp.
“They are very host specific and are only found on the bees Apis cerana and Apis mellifera,” Dr Roberts said.
The DAFF Analysis says should the wasp be approved for release, the risks of introduced parasitoids, mites or fungi would be managed under its current import procedures.
“These procedures include detailed examination of imported material, confirmation of identity and breeding through one generation before release. For this reason contaminating pests are outside the scope of this risk analysis,” the Analysis says.
