New lure to trap rusty grain beetle

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Identifying the presence of stored-grain insects is the first step in applying the most effective control strategies

Photo of pheromone lures

The pheromone lures have been tested and found to kill rusty grain beetles. Until the development of the pheromone lure, the rusty grain beetle was the only major grain storage insect not to have a commercial lure.

PHOTO: Research Directions

As an organic chemist, Dr Stephanie Smith considers the use of pheromones as the most obvious and effective tool for monitoring grain pests.

Dr Smith has developed a lure that attracts a high-priority stored-grain insect, the rusty grain beetle (Cryptolestes ferrugineus), as part of a project funded by the GRDC through the Plant Biosecurity Cooperative Research Centre (CRC) to improve surveillance tools.

“The chemical compounds we are using are the same ones that these insects have been producing and responding to throughout their evolution,” she says.

“They are not going to become resistant to these pheromones in the way they become resistant to phosphine.”

Dr Smith is CEO of Research Directions, the Queensland company that has synthesised the pheromones and is commercialising the lures.

Although the rusty grain beetle is not as widespread as some other stored-grain pests, such as the lesser grain borer, it has rocketed up the priority list following the emergence of strong resistance to phosphine.

It is this development that has made monitoring more urgent.

It takes up to eight days to kill most stored-grain insects at the highest label rate of phosphine (720 parts per million) – but resistant rusty grain beetles are requiring 16 to 18 days of phosphine applied at the highest label rate.

Of Australia’s four major pests of stored grain, the rusty grain beetle was the only one not to have an existing commercial lure, until Dr Smith’s intervention.

Although the two aggregation pheromones the insect produces were discovered by Canadian researchers in the 1970s they had not been successfully synthesised for commercial manufacture. (Aggregation pheromones are not sex pheromones; they attract male and female insects equally.)

Dr Smith says the new lure uses two pheromones, one of which was particularly difficult to manufacture, and extensive experimental work has been required to optimise the efficiency of manufacture of the two components.

The lures have been successfully tested in the field by entomologist Dr Andrew Ridley from the Queensland Department of Agriculture and Fisheries, in collaboration with GrainCorp, earlier this year.

Kansas State University has also been conducting trials with the lures in the US. The lures have been found to attract both adult male and female rusty grain beetles, and all females caught have been young and fertilised.

Dr Smith says it should be possible to use the lures for both monitoring and control.

“It would be ideal to eliminate the pest from the grain, before it actually goes into the silos in the first place,” she says.

Research Directions will commercialise the lures internationally for use in monitoring stored grain and other food products for the presence of rusty grain beetles.

The lures cost $8.50 each and are available from Research Directions, which will provide advice to customers on suitable traps for the lures.

More information:

Dr Stephanie Smith, Research Directions
07 3870 8346
stephanie@researchdirections.com.au

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GRDC Project Code NPB00013, Plant Biosecurity CRC Code 5073

Region National, North, Overseas