In mid January of this year when Tropical Cyclone Whatshername graciously delivered rains down here in the winter rain areas of the south, White Gum Valley experienced a strange nocturnal phenomenon.
At 8pm on the second day after the rains the lowest part of the Valley was filled with a blanket of sound; thousands of short sharp croaks weaving together as if burglar alarms in every house had developed croaking colds and had been set off all together. The sound was persistent and pervasive and quite disconcerting.
Thinking the chorus came from burrowing frogs, Ken and I were quite excited and we spent some time in the dark ferreting around under shrubs along the verges of Hope Street. Nary a frog was to be seen but Ken’s sharp eyes caught sight of a long brown insect scurrying away into a storm water drain.
This was in fact one of our singers. A mole cricket.
These large burrowing crickets have apparently become more numerous in recent years in the Perth area. There are three species involved and none of them was found in WA before the 1990s. As they are not recorded from natural bushland, it is possible they were introduced from elsewhere - perhaps in compost. Thought to be related to ordinary crickets the mole cricket looks however more like a sandgrouper and has rakes on fore and aft legs for digging its tunnels. Only some mole cricket species are garden pests in that they eat roots and seedlings, others are omnivores like the true crickets.
Google has this to say about their calls -
‘Singing characteristically commences at dusk, often after rain, and ceases within a few hours. The songs of mole crickets are deeper than those of typical crickets and many people have attributed them to frogs.’