A CATERPILLAR that usually appears after unusual amounts of summer rain has been discovered in the Calingiri area, intriguing scientists and giving farmers hope for a good season.
Reports of hawk moth caterpillars, along with budworms and pasture day moth caterpillars, have been on the increase with the Department of Primary Industries and Regional Development (DPIRD) stating the sightings are pretty rare as they are not a common pest in the region.
DPIRD field crop entomologist Dustin Severtson said the hawk moth caterpillar wasn't one normally seen in paddocks in that area.
"We try and get a heads up on what we should expect in the lead up to the season and the thing we look at is how much rain we've had and how much green bridge there is for issues like caterpillars and aphids," Dr Severtson said.
"This year, we've had quite a good amount of rain in the northern and central ag regions, whereas in the past two years it's been like a desert in the lead up to the season and the green bridge wasn't an issue.
"But this year, it's not just local rain which we've had a lot of, there's been a lot of rain in the north eastern pastoral areas, all the way from Kalbarri to Kalgoorlie and even north of there."
There are reservoirs of a lot of native moths in those areas further north, with cyclonic weather patterns causing the populations to act strangely.
"The weather causes weird things and one of those is the migration of these moths that we don't tend to see," Dr Severtson said.
"About 10 years ago we had a similar cyclonic event happen which brought huge amounts of rain to the Northampton area and it brought down this type of locust called the spur-throated locust."
Bolgart grower Julian McGill said he had been seeing the caterpillars since the summer rain.
"We got 50 millimetres about four weeks ago and with the green feed and volunteers cereals that are growing in the stubble, we always expected some sort of bugs," Mr McGill said.
"These caterpillars were huge, some would have been three inches long and as fat as my little finger, I've never seen them that big before."
Mr McGill said he only saw them by chance.
"Normally you're driving along the paddock at 50 kilometres an hour and you don't see anything, but they were coming down to my koonac dam for a drink.
"There would have been 15 to a square metre and that says to me there's a lot more out there."
Dr Severtson said DPIRD did not recommend that people go out and spray their volunteer cereals, which were essentially weeds.
"Having said that, if the green bridge isn't broken, where the weeds are completely dead for at least two weeks before the crop is coming out of the ground, there is a risk all those pests transfer onto the crop," he said.
Mr McGill said if the caterpillars were lured by rain that could be a sign of an exciting upcoming season.
"I've never seen them here before, I've been farming since I was 10-years-old and I've never seen a caterpillar like it before," he said.
"But if they come with rain, hopefully mother nature is trying to tell us something."
