The Press

Insectaged­don should freak us out

- Phil Lester Professor of insect ecology at Victoria University of Wellington

Arecent review has demonstrat­ed a ‘‘dreadful state of insect biodiversi­ty in the world, as almost half of the species are rapidly declining and a third are being threatened with extinction’’. This should be a substantia­l wakeup call. You should be concerned.

The review examined 73 studies that repeatedly surveyed insects for 10 years. Their analysis included work from Germany showing a 76 per cent decline in flying insect biomass over 27 years.

This insect Armageddon or ‘‘insectaged­don’’ is a global phenomenon. Puerto Rico was found to have experience­d up to 98 per cent biomass loss in some rainforest habitats over a 36-year period.

New Zealand insects are in crisis too. We have very little data for the vast majority of our bugs.

Probably the best audit so far has shown 32.5 per cent of the invertebra­te species for which we have data are threatened or at risk. A total of 49 per cent of our carabid beetle species are threatened or at risk. Extinction­s have already occurred.

Entomologi­sts are in agreement that an ‘‘insectaged­don’’ is happening here: we’ve seen what is probably a long and gradual decline in insect species and abundance over several decades.

What is causing the rapid global decline of insects? The study points to habitat loss by conversion to intensive agricultur­e and urbanisati­on, pollution by synthetic pesticides and fertiliser­s, pathogens and introduced species, as well as climate change.

This insectaged­don is catastroph­ic. It’s worth quoting the review here: ‘‘The pace of modern insect extinction­s surpasses that of vertebrate­s by a large margin . . . it is evident that we are witnessing the largest extinction event on Earth since the late Permian and Cretaceous periods. Because insects constitute the world’s most abundant and speciose animal group and provide critical services within ecosystems, such [an] event cannot be ignored and should prompt decisive action to avert a catastroph­ic collapse of nature’s ecosystems.’’

This isn’t the first study or review to highlight a massive, catastroph­ic and ongoing extinction of our insects. Previous insectaged­don studies have been published, with supporting media coverage and statements from other scientists (‘‘if we lose the insects, then everything is going to collapse’’). But then little else happens.

Just as the insectaged­don is a worldwide phenomenon, the lack of government action is similarly near global. A UK entomologi­st has lamented that we have seen little in the way of urgent expert task forces and the dedication of research funding into entomology.

We’ve seen few universiti­es advertisin­g entomologi­cally focused PhD positions with the goal of solving these problems.

In New Zealand, we have special funds and groups formed for the conservati­on of single species, such as with solving the kauri dieback problem. That funding and work is fantastic and deserves ongoing support. And to be fair there is some funding for invertebra­te conservati­on through the Department of Conservati­on and National Science Challenges.

The New Zealand public is engaged, with programmes such as ‘‘trees for bees’’ benefiting many more insects than just exotic honey bees. But there is more and more evidence that one of our most vital widespread and speciose groups of biodiversi­ty is in major crisis mode. We have to do better.

Many insect species seem unlikely to go extinct to me. Population­s of pests such as invasive ants, cockroache­s, grass grubs, mosquitoes and social wasps seem to be doing just fine. Some of these species even seem to be benefiting from climate change and agricultur­al intensific­ation.

But do we want these pests to replace our native bees, butterflie­s and beetles? Are these pests the legacy we leave our children?

Do we really want future generation­s, as some predict, fighting for ‘‘survival in a toxic world covered in dung’’ and starving ‘‘due to crop failures’’?

We need to understand patterns on insect decline and mechanisms for a reversal here in New Zealand. We have some world-leading entomologi­sts and researcher­s at our universiti­es, museums and Crown research institutes.

I urge the Government to make it a priority to help the public and these scientists understand and reverse insect declines.

How many more times do we need to scream catastroph­e? Let’s use every tool we have in the box to reverse the insectaged­don.

New Zealand insects are in crisis too ... Extinction­s have already occurred.

 ??  ?? The carabid beetle Megadromus. Another carabid is reported to have gone extinct in Canterbury because of dairy conversion­s.
The carabid beetle Megadromus. Another carabid is reported to have gone extinct in Canterbury because of dairy conversion­s.

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