Australian plague locusts

* Low densities of adult locusts have been observed in north-east Victoria and egg-laying may commence later in the month. * Eggs laid in the Victorian Mallee earlier this year are likely to hatch soon. * Bands of nymphs in NSW may appear in November but the likelihood of significant bands in Victoria is low.

 

Where have they been reported?

Adult Australian plague locusts (Chortoicetes terminifera) have been observed at a number of locations over about 100 km in north-east Victoria, following the strong north westerly winds on the 28th and 29th September. These appear to be low densities of overwintering adults that may have hatched locally, or have been blown in from the NSW Riverina. Egg-laying by these adults may not occur for a couple of weeks or so.

The Victorian DEPI and the Australian Plague Locust Commission (APLC) report that, during autumn, there was some localised medium density egg-laying in the area south of Robinvale (Victorian Mallee). Low density egg-laying may have been more widespread across the Northwest region.

Outlook

The APLC outlook for spring 2014 is for a widespread, low to medium density nymphal generation in several regions of NSW, with the likelihood of localised bands developing in parts of the Central West, Riverina, Far West and Far Southwest regions. Widespread regional infestations are unlikely in spring. An increase in adult populations to medium densities and the formation of small swarms in restricted areas is possible in October and November.

In Victoria, hatching of over-wintering eggs is expected to commence from early October and will continue throughout the month, with localised medium to high-density nymphs possible in the Annuello/Manangatang areas of the Victorian Mallee.

Our advice

The risk to grain crops through locusts this spring is low. Nevertheless, in Victoria, we encourage reports of immature or adult locusts to the Victorian DEPI through the Customer Service Centre (136 186
) or email plant.protection@depi.vic.gov.au. DEPI is particularly interested to receive any reports of egg-laying. In NSW, reports of egg-laying should be directed to the APLC.

 

* Sources of field reports of locusts

Gordon Berg - Victorian Plague Locust Commissioner (Department of Environment and Primary Industries)

Mike Halsey – Business Manager, Murray Darling Freshwater Research Centre (Victorian North East)