Situation Overview

A migration of adult locusts from New South Wales occurred in January and February 2009 but was confined to an area immediately west from Echuca. Egg laying was reported at Echuca. The adults moved south and west reaching Terrick-Terrick National Park where further egg laying occurred. The eggs near Echuca hatched and the hoppers developed very slowly into poor condition adults with no direct evidence of subsequent egg laying. The eggs at Terrick-Terrick National Park hatched later than those at Echuca and did not survive to adults.

Due to high mortality it is very unlikely that high numbers of eggs (termed egg beds) were laid. Any eggs in the ground are likely to hatch during October 2009.

The main areas where some hatching may occur are:

a). Echuca to Lockington
The numbers of hoppers hatching at these sites are likely to be very low number and hatching sites scattered patchily across the landscape. Formation of bands is extremely unlikely. The numbers are likely to be so low that hoppers probably will not be detected.

b). Colbinabbin
The Colbinabbin area is very small and confined. Hatching may occur and any hoppers may be easier to find than in other areas because of the confined nature of the area.

c). Tungamah
If there are any eggs in the ground north of Tungamah, they are likely to be scattered. The area is much smaller than the Echuca-Lockington area. It is possible that some of the hoppers that were present early in the year may appear as adults in very small numbers this spring.

DPI will monitor these areas. Landholders should report sightings to the Locust hotline 1300 13 5559.

It is possible that migrations of adult locusts may enter Victoria later in the season. A large nymph infestation is expected in central west NSW this spring. However the probability of this posing a threat to Victoria is still low at this point in time. DPI will monitor the situation interstate through its membership of the Australian Plague Locust Commission and will advise any change to threat levels if they arise.

Controlling locusts

It is important to control locusts early in the season to minimise potential damage to crops and pastures. Locusts are easiest to control during their early life-cycle stage when they are hoppers and unable to fly. Once they become adults, it is much more difficult and expensive to effectively treat locust infestations.

Landholders are urged to control locusts at the early stage of development by using one of the several chemicals registered for use in the specific control of locusts. Read more information on these chemicals.

If no control is undertaken on the first generation during spring and there is adequate green feed for developing adult locusts, a more significant and dispersed egg-laying period occurs during early to mid-summer.

The DPI is the lead agency tasked with coordinating the Victorian Government’s response to locust hatchings in the State. Further information about the current situation in Australia is available from the Australian Plague Locust Commission.


Locust Incursions since 2000

The latest incursion into Victoria resulted from a major outbreak that was initiated in south west Queensland in autumn 2004. Locusts arrived in Victoria in autumn 2004, survived as eggs in the ground through that winter and a relatively small population survived through to April 2005.

In spring 2005, very large numbers of hoppers emerged from eggs that had been laid near Mitiamo and Swifts Creek. Swarms of adults developed from these hoppers at both locations. Despite extensive control, eggs were laid in various locations within 100km of Mitiamo in December 2005 and around Swifts Creek in December 2005 and January 2006. The eggs hatched through January and February 2006 forming bands of hoppers. Very few hoppers survived to adults and no swarms were reported through late summer and autumn of 2006.

DPI and landholders ran an extensive control campaign in both the Mitiamo and Swifts Creek areas. Through spring 2005 and summer 2006, DPI sprayed in excess of 30,000ha of locusts, mostly hoppers, and ran incident control centres and control campaigns from Kerang and Swifts Creek. The expenditure in 2005-6 by DPI was $4.4m. The control campaign commenced in October 2005 and was not completed until March 2006 and was highly successful.

The outbreak was concentrated in two areas, north central Victoria for up to 100km around Mitiamo, and in the Tambo Valley around Swifts Creek.