And you thought you had mozzies ?

The largest mesquite infestation in Australia is located in the Pilbara region of Western Australia. Most of it is contained within a ca 150000 ha area, of which approximately 30,000 ha is dense. The core infestation is located entirely on a single property, Mardie Station, although it is also spreading onto stations to the south and isolated mesquite has also been recorded from many other properties in the region.

http://www.ento.csiro.au/weeds/mesquite/pilbara_mesquite.html