Thursday, 8th April, 2010
By Gina Wilson The city has been swarmed with locusts but come spring this will feel like a holiday.
Good rain during the summer has led to the outbreak of "millions and millions" of locusts which have now infested four states, but the city can expect a major infestation in spring. Director of the Australian Plague Locust Commission Chris Adriaansen said nymph hatchings around September would do far more damage than the current outbreak but that plans were now in place to try and deal with the bigger infestation.
"It will be a big problem come spring," he said. "It will take a very big collaborative effort between landholders, state agencies, the Livestock Pest and Health Authority to try and manage it. It will be a major infestation." Mr Adriaansen said the current locust outbreak was the biggest in as many as 10 years.
"It's a reflection on the fact that we've had very good rain and very good pasture growth," Mr Adriaansen said. "Adults and nymphs from south west Queensland have moved on to NSW, SA and northern Victoria. "The (locusts) are presently moving southwards to Broken Hill from north west NSW.
"We haven't seen plagues of this magnitudes in eight to 10 years. Two thirds of inland Australia is affected." Mr Adriaansen said the locust could breed up to four generations in one September to April season. "So one female could lay between 250 and 300 nymphs."
In Victoria some of the swarms have been as big as 20km by 12km and have up to 30 million locusts. Mr Adriaansen said the locusts swarming Broken Hill were now looking for a place to lay their eggs and could travel up to 700 kilometres per night or 50km in a day flight looking for the right conditions.
Mr Adriaansen said locusts also fly extremely high in order to catch jet streams. "We had a surveillance flight that (found) a swarm at 3,000 feet." The APLC recently sprayed more than 200,000 hectares of land in what they call nymph band control, or spraying the baby or immature locusts, but they are currently not spraying adults. "We don't want to eradicate the (nymphs), just ... take out 60 to 70 per cent of the population," he said.
"We're not doing any adult swarm control at this stage because it has very little impact - less than five per cent of the population." Unlike the spur-throated locusts that have invaded Longreach, in central Queensland, the Australian plague locust (APL) is not too interested in trees or vegetable patches. "They are a sub-tropical species so they stay in central Queensland, moving north to breed," he said.
"The APL will eat grass, pastures and crops ... not really leaves and vines." The locusts are expected to stay around for the next three to four weeks. "Some will keep moving and some will stay ... until the end of April or the first week of May."
The locusts seen in the city were hatched six to eight weeks ago and Mr Adriaansen said there's not much residents can do to rid them."Inside you can use a fairly standard insect spray," he said.
"Outside given the amount your chances of having any significant impact is fairly limited."