Biosecurity SA has analysed results of a recent locust survey it conducted in the Mid North in conjunction with the Australian Plague Locust Commission.

The survey found the overall locust population in South Australia this autumn is lower and less widespread than at the same time last year. It’s not expected that there will be any adult locust migration into SA this autumn.

The present adult locust population is expected to decline during April and is unlikely to cause any issues during crop sowing.

There have been no confirmed reports of egg-laying. However, some highly sporadic egg-laying from the existing adult population is likely during the remainder of this month and into early April, resulting in scattered mostly low density egg beds.

Some of these eggs will hatch in autumn but most will now enter winter diapause (suspended development) and not hatch until spring. There is no expectation of a significant locust population developing from any autumn hatchings.

The survey covered areas of the Mid North where dense hopper bands were present during February (around the Koolunga/Yacka to Gladstone districts) and also adjacent areas further south from Tarlee, north to Quorn and Hawker, and west to Burra/Yunta/Broken Hill. Separately, the APLC surveyed from Renmark to Burra.

Forecast from autumn to spring

In spring, some highly localised hatching of hoppers can be expected to occur in areas where adults laid eggs in autumn. While the extent of egg-laying is unknown, the spring population is expected to be lower and less widespread than the spring population of 2011.

Any autumn and spring populations should be well within the capacity of landholders to control on individual properties.

Landholders are still encouraged to report any egg-laying activity to Biosecurity SA through the hotline on the above number.