AGRONOMISTS in Victoria’s Mallee have noticed white ants burrowing into locust egg beds and eating the eggs, and have said there are localised areas where locust hatchings will be cut drastically by the termites.
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However, while official plague locust monitors acknowledge it is possible for the white ants to eat locust eggs, they warn it will not have a significant impact on hatchings.
Agrivision Ouyen agronomist Grant Gibbins said there were many reports in his area of white ants eating locust eggs.
“I don’t know whether it is because we are looking more closely than usual, but there appears to be more white ants than usual and we are generally finding them in the areas where there are locust egg beds.
“In certain egg beds, the amount eaten out by the termites will be enough to reduce hatchings by quite a bit, up to 50pc we think.”
However, Victorian plague locust commissioner Gordon Berg warned farmers not to be too optimistic about termites reducing locust numbers.
“Theoretically it is possible, but I would suggest the total mortality rates would be even less than that inflicted by mice, another potential predator spoken about earlier in the year.
“You do find termites in the same areas as locust egg beds, but it’s a matter of whether they are having any direct impact.
“People are seeing them with locust eggs, and you may get mortality in the eggs and associate it with the termites, even though that is not the cause.”
Tempy farmer Leonard Vallance said the white ants appeared to be lowering locust numbers.
“We’ve found the same thing in different paddocks, and where the white ant population is high, we have seen very low hatchings of hoppers in the same area.”
Mr Gibbins said an inspection of locust egg beds appeared to support the theory that white ants were eating the eggs.
“You dig up the egg beds and you basically find a heap of termites in a bit of a channel.
“They’ve then found an egg sac and cleaned it out, eating all the eggs.”
Mr Gibbins said the highest concentration of white ants had been found in no-till paddocks or those adjoining scrub.
He acknowledged the white ants were not going to be a substitute for farmer control of the locusts, but said it was interesting to see their impact on hatchings.
Meanwhile, he said hatching had begun in earnest in the Ouyen district on bare ground, predominately around fencelines, where soil temperatures had reached above 20 degrees.
However, in crops under the canopy, the temperatures are generally only around 17 degrees, and this has not been hot enough to trigger hatchings.
Mr Berg said the hatching schedule was proceeding much as anticipated.
“Unfortunately, its going like we forecast, which is a worry, as we predicted a big problem.
“We are still expecting high survival rates of the hoppers, in particular with all the green feed around, due to the good early spring.
“In a drought year, there’s less for the hoppers to eat and mortality rates are higher.”
Mr Berg said hatchings were spreading south to areas such as Swan Hill and Ultima.
