The silence of the cicadas

CICADAS: Undoubtedly the sound of summer.
CICADAS: Undoubtedly the sound of summer.

The classic Kiwi summer might be synonymous with the deafening sound of cicadas, but in Wellington this year they have been decidedly muted.

The loudest and most common of New Zealand's estimated 70 cicada species - the green and black Amphipsalta zelandica - has been staying silent underground.

Landcare Research entomologist Thomas Buckley said the stalled emergence of the fat, loud chirpers - known as the chorus cicada - was probably due to a "strangely" damp late spring and early summer. But in Auckland and Northland the buzz had already arrived and Mr Buckley said he expected the noisy nymphs to start chirruping and clicking in earnest within the next two weeks in Wellington.

Because they spend most of their lives underground, cicadas remain something of a mystery to insect experts. Amphipsalta zelandica is thought to emerge after two or three years.

Once above ground the males sing to attract females and the couples mate. The females lay eggs and then both males and females die a few weeks later.

The jarring din they make can reach more than 100 decibels in the bush, exceeding standard noise safety limits.