GIPPSLAND residents may have noticed some leggy but unwelcome visitors in recent weeks, as recent rains and humid weather create ideal “growing” conditions.
Black millipedes in plague numbers are on the march, and in some cases have invaded homes and sheds.
Agriculture Victoria entomologist Antonette Walford said the millipedes were black Portuguese millipedes, which were accidently introduced from Portugal in 1953, and were known to be an invasive pest.
“It is common to see high numbers of these millipedes at this time of year,” she said.
“However, with the La Nia climate conditions at present, insect population numbers have increased significantly, which is likely to explain the large numbers found in the area.
“Industry and community reports of unusual pests help to support Victoria’s biosecurity system, keeping our plant industries and environment safe from pest threats.”
With no natural predators, Portuguese millipedes can multiply rapidly, with one egg able to hatch hundreds of offspring.
While not technically dangerous, they have been known to cause delays with train systems in Victoria between Melbourne and Ballarat, where large numbers on the tracks have resulted in train cancellations due to the ‘greasing’ of the tracks when trains run over them, creating slimy tracks and reducing traction.
Crop feeding damage is relatively rare and somewhat unusual as black Portuguese millipedes generally feed on organic matter such as leaf litter, decaying wood and fungi.
However the millipedes have been reported as damaging seedlings of brassica and cereal crops and soft, ripe fruits such as strawberries.
Millipedes sheltering in bunches of wine grapes at harvest (autumn) may taint wine.
During hot dry weather, they hide in the soil, and rainfall often stimulates activity.
They can be found under rocks, stubble residue, wood, or when digging up soil.
Refuge traps such as carpet squares, tiles or pot plant bases can be used to detect the millipedes.
It is inadvisable to step on them, as squashed millipedes have a distinctive smell – a pungent odour designed to repel predators.
Chemical and physical barriers can put a stop millipedes entering homes, while getting rid of leaf litter will also remove their food source.
Residents can report unusual occurrences of pests to the Exotic Pests Plant Hotline on 1800 084 881 or online.