Agriculture Victoria working to identify locusts collected in Gippsland

Thirty-three specimens were collected from the Tambo Valley, including areas north of Swifts Creek and as far south as Bruthen and Mossiface.

Agriculture Victoria Senior Entomologist and Victorian Plague Locust Commissioner Dr Kyla Finlay said work was underway to confirm the identification of the specimens.

"An initial visual identification of the specimens from images suggest the majority may be Yellow winged locust and other native grasshopper species, with relatively few Australian plague locust," she said.

"However, the Yellow winged locust can behave in a similar manner to Australian plague locust and form high density swarms and bands.

"We are conducting surveillance in the areas where reports have been made to monitor the extent of the occurrences.

"There have been positive identifications of Australian plague locusts in the area before, in 2010 and 2018, however, these occurrences are intermittent."

There are more than 500 types of locusts and grasshoppers in Australia and of these, only four are regarded as economically important.

Only two of these, the Australian plague locust and the Yellow winged locust, regularly occur in Victoria.

Agriculture Victoria Industry Development Officer John Commins said if positively identified, the locusts could potentially impede the opportunity for farmers to cut hay and make silage.

"When present in large numbers, they can strip green crops, severely limiting the capacity of farmers to build up hay and silage reserves, and harvest summer fodder crops," he said.

Mr Commins said farmers could potentially protect fodder crops by laying down a barrier spray around crops to stop young locusts in their tracks when they are banding and marching.

Agriculture Victoria said a number of insecticide products were available for the treatment of Australian Plague Locusts and those products would also work for Yellow winged locusts, although landowners should seek expert advice and all chemicals must be used in accordance with Victorian legislation.

Dr Finlay said the most effective time to spray was when the hoppers were relatively small and were just starting to form aggregations or bands on the ground.

For Australian plague locusts this is about two weeks after hatching when the hoppers are around 10mm long.

Yellow winged locust hopper will take slightly longer to reach the aggregation stage and be slightly larger.

"By spraying and controlling them at this point in their development cycle, this will suppress any population build-up and reduce potentially high population levels next year," she said.

Australian plague locust can be identified by the large dark spot on the tip of the hindwing and the distinctive red shanks on the hind legs.

Their body colour varies and can be grey, brown or green. Adult males are 25 - 30mm long while females are 30 - 45mm long.

The Yellow winged locust are larger than the Australian Plague Locust.

Adult males are 25 - 35mm long and adult females 35 - 40mm long. They are easily distinguished by the bright yellow colour and brown banding on the hindwing.

For more information on identification and monitoring and to report sightings of plague locusts, call Agriculture Victoria on 136 186.