Buzzing away: are insects on the verge of global extinction?

It's odd how some of these posts get initiated. For this particular one, there were two driving factors. One was passing a new house on my way to work where apart from the concrete driveway, the front garden consisted solely of a large square of artificial grass; the owners are clearly not nature lovers! The second inspiration was listening to a BBC Radio comedy quiz show, in which the panel discussed the recent report on global insect decline without being able to explain why this is important, apart from a vague mention of pollination.

Insect biologists have long sung the praises of these unrewarded miniature heroes, from JBS Haldane's supposed adage about God being "inordinately fond of stars and beetles" to EO Wilson's 1987 speech that described them as "the little things that run the world." In terms of numbers of species and individuals, invertebrates, especially insects, are the great success story of macroscopic life on our planet. So if they are in serious decline, does that spell trouble for Homo sapiens?

The new research claims that one-third of all insect species are currently endangered, extrapolating to wholesale extinction for the class Insecta over the next century. Although the popular press has started using evocative phrases such as "insect genocide" and even "insectageddon", just how accurate are these dramatic claims?

The United Nation's Red List currently describes three hundred insect species as critically endangered and a further seven hundred as vulnerable, but this is a tiny proportion of the total of...well, at lot more, at any rate. One oft-quoted figure is around one million insect species, although entomologists have estimated anywhere from 750,000 up to 30 million, with many species still lacking formal scientific identification. The hyperbole could therefore easily sound like unnecessary scaremongering, until you consider the details.

The new report states that butterflies and caddis flies are suffering the greatest decline, while cockroaches - as anyone who has faced a household infestation of them will know, they are likely to remain around until the end of world - and flies are the least affected orders. So, to paraphrase Monty Python, what have the insects ever done for us?

Pollination is of course of key importance, to both horticulture and un-managed 'wild' environments. Insects are near the base of many food webs; if numbers were much reduced, never mind removed, the impact on the rest of the ecosystem would be catastrophic. With the human population set to top ten billion in thirty years' time, we require ever larger regions of productive land for agriculture. They may be small at an individual level, but arthropods in general total about seventeen times the mass of all us H. sapiens. Insects replenish the soil, as alongside bacteria they break down dead matter and fecal material. So important is this latter function that New Zealand has been trialling non-native dung beetles to aid cattle farmers.

One key way to save fresh water and lessen the generation of the potent greenhouse gas methane is to reduce meat consumption in favour of insect protein. If insects are no longer around, then that will be an additional challenge in reducing environmental degradation. This of course also ignores the fact that insects are already a component in the diet of many developing nations. Last year I wrote about how scientists have been creating advanced materials derived from animals. Again, we are shooting ourselves in the foot if we allow this ready-made molecular library to be destroyed.

What is responsible for this global decline? Perhaps unsurprisingly, it turns out to be the usual suspects. Agricultural chemicals including pesticides have been associated with honey-bee colony collapse disorder (not incidentally, some tests have found honey samples with neonicotinoids - the mostly widely-used insecticides - exceeding the recommended human dosage) so clearly the same culprit is affecting other insects. Fresh waterways, home to many aquatic insect species, are frequently as polluted as the soil, either due to agricultural run-off or industrial contaminants. Wild landscapes are being converted with great haste into farm land and urban sprawl, with an obviously much-reduced biota.

Climate change is playing its part, with soil acidity increasing just as it is in the oceans. Even areas as remote as central Australia have seen marked decreases in insects as higher temperatures and lower rainfall outpaces the ability to adapt to the new conditions. I've often mentioned the role of invasive species in the decimation of indigenous vertebrates, but insects are equally prone to suffer from the arrival of newcomers. Although New Zealand has very strict biosecurity protocols, the likes of Queensland fruit flies and brown marmorated stink bugs are still occasionally found in or around ports of entry.

Many nations have no such procedures in place, resulting in local species being out-competed or killed by introduced species or pathogens to which they have no resistance. Until fairly recently, even New Zealand had a lax attitude to the issue, resulting in the decline of native species such as carabid beetles. When I conducted a brief survey of my garden in 2017 I found that one-third of the insect species were non-native, most of these being accidental imports since the arrival of European settlers.

If insects are so vital to our survival, why has there been so little interest in their well-being? There are some fairly obvious suggestions here. Firstly, at least in Western cultures, insects have been deemed dirty, ugly things that can be killed without a second thought. Wasps, ants and cockroaches in particular are seen in this light of being unwelcome pests, with typical insect-related phrases including "creepy crawlies" and "don't let the bed bugs bite".

It's fairly well-known that malaria-carrying mosquitoes are the most dangerous animals for us humans in terms of fatalities. The widespread outbreaks of the Zika virus haven't done them any favours either. As Brian Cox's television series Wonders of Life showed, their small size has given them veritable super powers compared to us lumbering mammals, from climbing up sheer surfaces (as a praying mantis was doing a few nights' ago on my window) to having amazing strength-to-weight ratios. All in all, insects are a bit too alien for their own good!

Clearly, scale prejudice is also a key factor. On a recent trip to Auckland Central Library I only found one book on insects versus dozens on birds. Photographic technology has been a double-edged sword when it comes to giving us a clearer picture of insects: close-ups are often greeted with revulsion, yet until Sir David Attenborough's 2005 BBC series Life in the Undergrowth, there was little attempt to film their behaviour with the same level of detail as say, the lions and antelopes of the Serengeti. It should also be mentioned that when Rachel Carson's ground-breaking book about the dangers of pesticides, Silent Spring, was published in 1962, the resulting environmentalism was largely in support of birds rather than insects.

Among all this doom and gloom, are there any ways to prevent it? One thing is for certain, and that is that it won't be easy. The agricultural sector would have to make drastic changes for a start, becoming much smarter in the use of chemicals and be held responsible for the local environment, including waterways. Vertical farming and other novel techniques could reduce the need for new agricultural land and water usage, but developing nations would be hard-pressed to fund these themselves.

Before any major undertaking, there's going to have to be either a fundamental crisis, such as food shortages, in a rich nation or a massive public relations exercise to convince people to consider insects in the same light as giant pandas or dolphins. This is not going to be easy, but as David Attenborough put it: "These small creatures are within a few inches of our feet, wherever we go on land - but often, they're disregarded. We would do very well to remember them."

Valuing the velvet worm: noticing the most inconspicuous of species

Most of the recent television documentaries or books I've encountered that discuss extra-terrestrial life include some description of the weirder species we share our own planet with. Lumped together under the term 'extremophiles' these organisms appear to thrive in environments hostile to most other life forms, from the coolant ponds of nuclear reactors to the boiling volcanic vents of the deep ocean floor.

Although this has rightly gained attention for these often wonderfully-named species (from snottites to tardigrades) there are numerous other lifeforms scarcely noticed by anyone other than a few specialists, quietly going about their unassuming business. However, they may provide a few useful lessons for all of us, including that we should acknowledge there may be unrecognised problems generated when we make rapid yet radical modifications to local environments.

There is a small, unassuming type of creature alive today that differs little from a marine animal present in the Middle Cambrian period around five hundred million years ago. I first read about onychophorans in Stephen Jay Gould's 1989 exposition on the Burgess Shale, Wonderful Life, and although those fossil marine lobopodians are not definitively onychophorans they are presumed to be ancestral. More commonly known by one genus, peripatus, or even more colloquially as velvet worms, there are at least several hundred species around today, possibly many more. The velvet component of their name is due to their texture, but they bear more resemblance to caterpillars than to worms. They are often described as the ‘missing link' between arthropods and worms but as is usually the case this is a wildly inappropriate term in this context of biological classification. The key difference to the Burgess Shale specimens is that today's velvet worms are fully terrestrial: there are no known marine or freshwater species.

Primarily resident in the southern hemisphere, the largely nocturnal peripatus shun bright light and requiring humid conditions to survive. Although there are about thirty species here in New Zealand, a combination of their small size (under 60mm long) and loss of habitat means they are rarely seen. The introduction of predators such as hedgehogs - who of course never meet peripatus in their northern hemisphere home territory - means that New Zealand's species have even more to contend with. Although I frequently (very carefully) look under leaf litter and inside damp logs on bush walks in regions known to contain the genus Peripatoides - and indeed where others have told me they have seen them - I have yet to encounter a single specimen.

There appears to be quite limited research, with less than a third of New Zealand species fully described. However, enough is known about two species to identify their population status as 'vulnerable'. One forest in the South Island has been labelled an 'Area of Significant Conservation Value' thanks to its population of peripatus, with the Department of Conservation relocating specimens prior to road development. Clearly, they had better luck locating velvet worms than I have had! It isn't just the New Zealand that lacks knowledge of home-grown onychophorans either: in the past two decades Australian researchers have increased the number of their known species from just seven to about sixty.

Their uncanny resemblance to the Burgess Shale specimens, despite their transition from marine to terrestrial environments, has led velvet worms to be described by another well-worn phrase, 'living fossils'. However, is this short-hand in any way useful, or is it a lazy and largely inaccurate term? The recent growth in sophisticated DNA analysis suggests that even when outward anatomy may be change little, the genome itself may vary widely. Obviously DNA doesn't preserve in fossils and so any such changes cannot be tracked from the Cambrian specimens, but the genetic variation found in other types of organisms sharing a similar appearance shows that reliance on just external anatomy can be deceptive.

Due to lack of funding, basic taxonomic research, the bedrock for cladistics, is sadly lacking. In the case of New Zealand, some of the shortfall has been made up for by dedicated amateurs, but there are few new taxonomists learning the skills to continue this work - which is often seen as dull and plodding compared to the excitement of, for example, genetics. Most people might say so what interest could there be in such tiny, insignificant creatures as peripatus? After all, how likely would you be to move an ant's nest in your garden before undertaking some re-landscaping? But as shown by the changing terminology from 'food chains' to 'food webs', in most cases we still don't understand how the removal of one species might generate a domino effect on a local ecosystem.

I've previously discussed the over-reliance on 'poster' species such as giant pandas for environmental campaigns, but mere aesthetics don't equate to importance, either for us or ecology as a whole. It is becoming increasingly clear that by weight the majority of our planet's biomass is microbial. Then come the insects, with the beetles prominent both by number of species and individuals. Us large mammals are really just the icing on the cake and certainly when it comes to Homo sapiens, the rest of the biosphere would probably be far better off without us, domesticated species aside.

It would be nice to value organisms for themselves, but unfortunately our market economies require the smell of profit before they will lift a finger. Therefore if their usefulness could be ascertained, it might help generate greater financial incentive to support the wider environment. Onychophorans may seem dull, but there are several aspects to them that is both interesting in itself and might also provide something fruitful for us humans.

Firstly, they have an unusual weapon in the form of a mechanism that shoots adhesive slime at prey. Like spider silk, is it possible that this might prove an interesting line of research in the materials or pharmaceutical industries? After all, it was the prickly burrs of certain plants that inspired the development of Velcro, whilst current studies of tardigrades (the tiny 'water bears' living amongst the mosses) are investigating their near indestructability. If even a single, tiny species becomes extinct, that genome is generally lost forever: who knows what insights it might have led to? Although museum collections can be useful, DNA does decay and contamination leads to immense complexities in unravelling the original organism's genome. All in all, it's much better to have a living population to work on than rely on what can be pieced together post-extinction.

In addition, for such tiny creatures, velvet worms have developed complex social structures; is it possible that analysis of their brains might be useful in computing or artificial intelligence? Of course it is unlikely - and extinction is nothing if not natural - but the current rate is far greater than it has been outside of mass extinctions. Losing a large and obvious species such as the Yangtze River dolphin (and that was despite it being labelled a ‘national treasure') is one thing, but how many small, barely-known plants and animals are going the same way without anyone noticing? Could it be that right now some minute, unassuming critter is dying out and that we will only find out too late that it was a vital predator of crop-eating pests like snails or disease vectors such as cockroaches?

It has been said that ignorance is bliss, but with so many humans needing to be fed, watered and treated for illness, now more than ever we need as much help as we can get. Having access to the complex ready-made biochemistry of a unique genome is surely easier than attempting to synthesise one from scratch or recover it from a long-dead preserved specimen? By paying minimal attention to the smallest organisms that lie all around us, we could be losing so much more than just an unobtrusive plant, animal or fungus.

We can't save every species on the current endangered list but more attention could be given to the myriad of life forms that get side-lined by the cute and cuddly flagship species, usually large animals. Most of us would be upset by the disappearance of the eighteen hundred or so giant pandas still left in the wild, but somehow I doubt their loss would have as great an impact on the surrounding ecosystem than that of some far less well known flora or fauna. If you think that's nonsense, then consider the vital roles that bees and dung beetles play in helping human agriculture.

Although the decimation of native New Zealand wildlife has led to protective legislation for all our vertebrates and a few famous invertebrates such as giant weta, the vast majority of other species are still left to their own devices. That's not to say that the ecosystems in most other countries are given far less support, of course. But without funding for basic description and taxonomy, who knows what is even out there, never mind whether it might be important to humanity? Could it be that here is a new field for citizen scientists to move into?

Needless to say, the drier climes brought on by rising temperatures will not do peripatus any favours, thanks to its need to remain in damp conditions. Whether by widespread use of the poison 1080 (in the bid to create a pest-free New Zealand by 2050) or the accidental importation of a non-native fungus such as those decimating amphibians worldwide and causing kauri dieback in New Zealand, there are plenty of ways that humans could unwittingly wipe out velvet worms, etal. So next time you watch a documentary on the demise of large, familiar mammals, why not spare a thought for all those wee critters hiding in the bush, going about their business and trying to avoid all the pitfalls us humans have unthinkingly laid for them?

Mopping up spilt milk: pollution in the New Zealand dairy sector

It's been slow to dawn on New Zealanders, but for a country that prides itself on a '100% Pure' image our environmental pollution record is fairly appalling - and shows few signs of alleviation. Politicians who point to the large percentage of the nation's electricity generation coming from renewable sources, not to mention the slow but sturdy growth in hybrid vehicles, are completely missing the point: it has been claimed that over half of New Zealand's greenhouse gas emissions emanate from agri business.

Although the quantity of sheep in the country has plummeted from a 1982 peak of around 70 million to less than 30 million last year, cattle numbers continue to rise. There are about 3.6 million livestock on beef farms and circa 6.5 million dairy cattle. The latter sector generates twenty percent of New Zealand's exports and seven percent of its GDP, so it forms a substantial component of the kiwi economy. But with plans to double the country's dairy production by 2025, the term 'sustainable development' appears to be, well, unsustainable.

Since cattle create as much waste product as fourteen humans, it's not difficult to imagine some of the more obvious forms of dairy pollutant, smell and all. As New Zealand dung beetles are primarily forest dwellers there have been trials of introduced dung beetle species to help clean up the waste, with a reduction in nitrous oxide emissions from the soil and a lowering of cattle disease as side benefits. However, pastoral poo is only one element in the catalogue of pollutants caused by dairy farming.

Last summer I was taken to an outdoor swimming hole not far from Wanganui, consisting of a rectangular concrete-lined pool situated on the edge of a forest. I was informed that children had swam there until a decade or so, but no more: several signs warned that the water is contaminated and no longer safe for humans. This story has been repeated throughout New Zealand, with agriculture being by far the most common culprit. It isn't just artificial environments that have this problem; reports suggest that within the past twenty years about two-thirds of monitored swimming areas within rivers have become too polluted. And that's just for people; there's far less concern for the effects on river fauna and flora.

Although environmentalists have been issuing warnings for years, not enough has been done to alleviate this problem. Last month approximately five thousand inhabitants of Havelock North were taken ill due to tap water contaminated by campylobacter. The source was a series of bores which the director of the Infectious Diseases Research Centre at Massey University, Professor Nigel French, put down to pollution from sheep and cattle. Sources of contamination could include carcases of dead livestock, as well as faecal matter getting into waterways that provide the source of unchlorinated - and therefore at risk - tap water.

In fact, the outbreak appears to be the tip of the iceberg. Despite some hundreds of cases of illegal effluent discharge brought against New Zealand farmers each year, many more escape prosecution. It has to be said this seems to be a regular occurrence for the Ministry for Primary Industries, judging by the recent reports of their waiving prosecutions for commercial fishing vessels caught flouting bycatch and dumping laws. Turning a blind eye seems to be the order of the day when it comes to protecting food production - or at least the food producers. This philosophy seems to be driven by those who clearly have little understanding of the complexity - and at times fragility - of food webs. Not so much short-term thinking as profound myopia!

In addition to the organic matter there are chemical pollutants that can find their way into water supplies situated close to farms. Since the 1990s, the New Zealand Ministry for the Environment has been monitoring ground water for nitrates and has found levels substantially above those recommended for drinking water. Although chemical fertiliser has been blamed in addition to livestock effluent, environmental mapping suggests the latter is the primary cause, since the polluted areas heavily coincide with the widest-scale dairy production.

As well as polluting waterways dairy farmers have also been caught stealing billions of litres of water each year from rivers and aquifers, especially in the Canterbury region. Whilst not a form of pollution per se, this is obviously somewhat lacking in the environmentally-friendly stakes. The deforestation of low-lying plains for cattle grazing is also a source of pollution, as the lack of tree roots, besides allowing greater flooding, can generate increased run-off into rivers. This polluted water can lead to algal blooms, lowering oxygen levels and so endangering freshwater fish. That might not sound of any great concern except to diehard anglers, but for any whitebait fans, four of the five Galaxiidae species whose young form this delicacy are now said to be threatened.

The systematic destruction of forests to make way for pastoral land use has been repeatedly raised as a concern not just by environmental organisations but by the New Zealand Ministry of Agriculture and Forestry (MAF) itself. Their 2006 report claimed close to half a million hectares of the nation's forests were at risk of conversion to land for cattle grazing.

In addition, overseas forests are also affected: since 2008 the amount of palm kernels imported into New Zealand as a dairy cattle feed supplement has doubled to over 2 million tons per annum. This accounts for about twenty-five percent of global production and comes at the expense of destruction of rainforests in nations including Indonesia and Malaysia. Although the state-owned farm company Landcorp Farming Ltd is in the process of moving to a different supplement over the next year or so, the dairy giant Fonterra has not announced similar intentions. What's wrong with those guys: a surfeit of Milton Friedman in their formative years?

Having covered solids and liquids, it's time to move on to gas. As I've mentioned on various occasions, methane is a primary greenhouse gas. It was therefore shocking to discover that per capita, New Zealand has the greatest annual methane emission rate worldwide, accounting for over forty percent of the country's greenhouse gas emanations. The methane emission from dairy cattle alone has continually increased over the past quarter century, although the amount reported varies from ten percent to a whopping fifty percent or so. Perhaps that's not surprising, considering cattle can each generate up to 500 litres of methane per day!

There is some recent cause for hope, with various trials under way to reduce bovine emissions. These range from vaccination to selective breeding to diets bases on forage rape, with the latter showing that the change in feed affects fermentation - and therefore reduces methane production - in sheep. However, it wouldn't hurt to see the Government funding more research in this matter: one widely-reported paper last year was Massey University's The New Zealand Dairy Farming: Milking Our Environment for All its Worth, which received much criticism from the dairy sector when it was revealed to consist primarily of a student thesis.

It's very easy to become depressed with such deleterious effects coming from just one sector. Of course no nation can afford to rest on its laurels: we cannot turn the clock back. The halcyon image of bucolic ruralism is a myth perpetrated by those who have never worked on the land and farmers deserve the benefits of modern technology in their work as much as anyone. The development of sophisticated tools and software can aid the dairy sector in preserving the environment. as long as there is enough public money to support this eco-friendly research. But Government funding for this type of sustainable development appears to be sadly lacking. Doesn't it make sense that those who run God's Own Country should try a little harder to prove that the 100% Pure tagline isn't just marketing spin?

Dung roaming: a controversial approach to cleaning up New Zealand's cattle waste

Although I've already discussed the dangers of using biological control in various countries, a couple of recent events suggested I should write an update that concentrates on one particular example in New Zealand. I've mentioned elsewhere that my local reserve in Auckland is home to a large number of non-native species, from Australian eucalyptus trees and the associated (but accidentally imported) Emperor Gum moth, to California quail and Mexican gambusia fish. But having seen rainbow skink in my local environs, including a neighbour's garden, I was surprised to learn last week they are not native but yet another unplanned Australian import. Sure enough, the 1947 classic Powell's Native Animals of New Zealand makes no mention of the species in the page on the indigenous common skink and copper skink.

Earlier this year I read Quinn Berentson's superb Moa: the life and death of New Zealand's legendary bird, which lists fifty-eight avian species as having become extinct since humans first arrived in the country less than a thousand years ago. And of course this decimation of native fauna and flora may not yet have ended, with NIWA for example fighting a rear guard action against unwanted marine incomers such as polychaete worms arriving on ship's hulls and in discharged ballast water. Various sources suggest that well over one hundred introduced species of land animals, birds and fish are now widespread in New Zealand: what chance does the native ecosystem stand against this onslaught?

To add insult to injury, I recently read an OECD chart delineating business spend on research and development as a percentage of GDP, and was shocked to find that New Zealand was fourth from bottom of twenty-six nations, coming below western Europe, South Korea, Japan, Australia, Canada and the USA. Are our captains of industry really so short-sighted? As a country that depends extremely heavily on its dairy industry - an industry that is currently in dire straits - it seems sensible to invest a large amount of R&D in this sector. But alongside the eco-friendly solutions such as minimising methane emissions, there has been a new programme of biological control aimed at one particular side effect of dairy farming, namely the enormous amounts of cattle dung produced.

Across the Tasman, Australia has already been working on a similar scheme for the past half century, deliberately introducing numerous species of non-native dung beetles. New Zealand, home to over ten million cattle in a 3:2 dairy-to-meat ratio, obviously has issues with bovine manure management. Due to the lack of native ruminants the country's fifteen indigenous dung beetle species have evolved to mostly inhabit forests rather than grazing land.

There are various reasons why speeding up the rate of dung decomposition would improve farm land and the landscape in general, from preventing mineral imbalance in the soil and contamination of waterways to reduction in animal-infesting parasites such as nematode worms. But is it worth the risk to the greater environment, considering the dismal track record of biological control schemes around the world?

The new project is not the first time such insects have arrived in the country: in addition to three species accidentally imported from Australia and South Africa from the late Nineteenth Century onwards, the Mexican dung beetle (Copris incertus) was deliberately introduced into three areas in the 1950s but only thrived in the warm Northland climate. It is the scale of the new research that has set it apart: following caged field trials, the past two years has seen the widespread introduction of eleven non-native species across seven regions on both North and South Islands.

Bodies such as the Institute of Environmental Science and Research (ESR) have investigated the potential dangers to human health and the local ecology, even testing if possums, carriers of bovine tuberculosis, might see the exotic insects as a new food source. Even so, some professional scientists have deemed it a biosecurity disaster and one can see their point: using data from other countries' programmes is hardly a fool-proof comparison, considering the profoundly different indigenous ecosystems of Australia and New Zealand.

As a child I heard about the food chain or pyramid, but this is something of a misnomer. Just as natural selection works with bushes rather than linear progression, so there are food webs consisting of a complex series of trophic interactions. Although exotic dung beetles are unlikely to displace their native counterparts due to lack of shared environments, it is possible that other native species of grassland-living insects could suffer, such as humble earthworms. The problem is that without testing in various regions over long periods of time, it isn't viable to rule out such side consequences. Yet it isn't possible to undertake such tests without release into the wild: do we have something of a catch-22?

Having said that, there are no obvious signs that Australia's long-established dung beetle programme has had anything like the deleterious effects of its other biological control schemes, such as the cane toad fiasco. But then fifty years is a very short time in ecological timeframes and what to the casual glance of a farmer appears to be equilibrium could be apocalyptic at dung beetle scale. I wish the project good luck, but cannot help feeling that having received far more than its fair share of obnoxious aliens, New Zealand is the last place that needs yet more exotic species introduced onto its green and pleasant land.