SEED cleaners in the south of the State are working around the clock to separate millions of ladybirds from oilseed crops.
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While the ladybirds don't damage the crops, the problem they cause is they have to be cleaned out of the grain before growers truck their grain to CBH terminals or store it on farm for seed.
The overwhelming populations of vagrant ladybirds have inundated canola crops for a combination of reasons, one of which is to feed on lingering spring aphid populations.
Vagrant insects live on a plant but don't feed off that plant.
Albany-based Agriculture and Food Department entomologist Svetlana Micic said the populations had mainly been observed in canola swathes from crops that had a very high number of aphids, but weren't limited to only those crops.
"Aphids in crops would have attracted the ladybirds initially, which would have then laid eggs," Ms Micic said.
"In their larval stages the ladybirds would have fed on the aphids.
"However, at harvest there are no aphids left and all of the ladybirds are at the adult stages."
Ms Micic said ladybirds were commonly found sheltering in the swath rather than on the ground under it.
"In crops of swathed canola we found the swath attracted ladybirds because they used it as a refuge," she said.
This meant canola crops harvested standing up were found to have fewer ladybirds than swathed crops.
Ms Micic said during the summer heat ladybirds in native vegetation tended to use dense bushes as a refuge.
It was initially South Coast farmers who were warned about the large vagrant insect populations this year but farmers throughout the Great Southern and Wheatbelt experienced the ladybird problem.
Like a majority of canola growers in the State's south Tarin Rock farmer Philip Gooding said he had millions of ladybirds in his canola seed.
"I've never seen numbers like that before," he said.
"Now all the canola has been picked up and cleaned they've thinned out a bit."
Mr Gooding said he had piles of ladybirds a metre deep in the seconds from his seed cleaner.
Other common vagrant insects found in WA crops this year were bronzed field beetles, European earwigs and rutherglen bugs, all of which shelter on the ground under swathed canola plants unlike the ladybirds.
