Survey seeks to estimate damage, spread of grasshoppers in NWQ

One grazing couple whose newly-grown store of grass was decimated within weeks is John and Donna Paynter, who have been at Wando, south of Winton, for 40 years.

Six weeks ago, after 200mm of rain that fell in a four-day band, they were mustering sheep in for crutching amid lush green Mitchell, Flinders and button grass up to 60cm high.

That has since been reduced to dirt and scant stalks scattered about the paddocks.

"We're not on our own - there are neighbours and others who are just as bad or much worse," Mr Paynter said.

Related: Grasshoppers chew through Winton again

Thanks to an offer from friends at Lightning Ridge, NSW, with 22,660ha of fresh grass and no stock, they have this week sent six decks of No 7 and 8 PTIC heifers on agistment.

This has destocked their home block of 8100ha and left 160 cows and some weaners on their 4050ha additional area.

Mr Paynter said those cattle plus 3200 sheep about to lamb had a few months of feed left in front of them.

"That's another reason we offloaded cattle - it gives us two paddocks for the lambing ewes."

Asked about other ways of managing the impact of grasshopper damage that has been getting incrementally worse since early March, Mr Paynter said he would sell before he would spray.

Citing possible costs of $30 to $40/ha, he said chemical treatment had a limited lifespan and didn't guard against further infestations in the weeks following.

"It's just nature," he said.

They have sustained grasshopper damage before, including about 120ha chewed last year, but Mr Paynter said he'd never experienced such a severe loss of pasture.

The locations and severity of current grasshopper infestations are being collated by the GrazingFutures Central West and North West Department of Agriculture & Fisheries teams through a survey begun on April 9, aimed at improving their understanding of its scale, to support further scientific investigations.

"The survey will assist in documenting key issues such as the extent of grasshopper distribution, resultant pasture damage and estimates of economic impact," a spokeswoman said.

"The findings will be shared with producers who respond to the survey and should provide baseline data for other potential projects.

"Having information about the main grasshopper species' ecology could assist to predict situations like the current one and inform us about early or alternative management decisions which could lessen the economic impact to affected producers."

The survey has so far show that large populations have been observed from at least Hughenden south to Winton and Morella, Ilfracombe, Barcaldine, Longreach and further south towards Stonehenge.

Observations of an apparent preferences for certain types of country and plant species have been made, although all results need to be seen before anything can be made from that.

Questions include when producers received their first wet season rain, identifying what species they are seeing based on photographs, and an estimate of how much economic damage has been sustained to the business.

The survey notes that grasshoppers already observed seem to be four common species, that it's believed they will only persist for short periods, have a short life cycle and have relatively low impact.

It says that by the time an aerial response could take place, the life cycle of these grasshoppers is predicted to be complete.

At this stage the survey is open until May 1 but could be extended depending on the level of interest from respondents.