Opinion by Andi Cockroft, Chair, CORANZ
Exploring the Decline of Insects in Rural New Zealand (and What We Can Do About It)
For anyone who drove on rural roads in New Zealand fifty or sixty years ago, the memory is vivid: a windscreen plastered with insects after even a short journey. Moths, beetles, flies and other flying insects collided with the glass in such numbers that regular stopping to clean the screen was part of long-distance driving. Many older vehicles did not even have windscreen washers fitted as standard, or if they did, they were regularly used. Today, that experience has changed dramatically.
One rural North Island landholder, who regularly drives both modern vehicles and 30-year-old Land Rovers – whose aerodynamics can best be described as “brick-like” – has noticed a striking difference. Even after a full day of driving through rural districts, the windscreen remains almost spotless. This simple but powerful observation is repeated by countless others and forms part of what has become known as the “windscreen phenomenon.” While not a scientific measurement in itself, it aligns closely with a growing body of evidence that insect numbers are in decline across large areas of the world, including New Zealand.
This article explores the likely causes behind that decline – excluding 1080 and similar vertebrate poisons – and considers what practical steps could help reverse the trend.
THE QUIET DISAPPEARANCE OF INSECTS
Insects form the foundation of most terrestrial ecosystems. They pollinate plants, break down organic matter, recycle nutrients, and provide the base of the food chain for birds, reptiles, fish and mammals. A decline in insects is therefore not a minor issue – it ripples through every level of the natural environment. Even people with no particular affection for insects depend on them daily through food production, soil health and healthy ecosystems.
Globally, a number of long-term studies have recorded sharp drops in insect biomass and diversity, particularly in agricultural landscapes. While exact figures differ between regions, the overall picture is consistent: fewer insects, fewer species, and fewer large, visible swarms than in past decades.
In New Zealand, hard long-term datasets are limited compared with Europe or North America. Nevertheless, researchers, landowners, gardeners and conservation workers all report the same quiet change: fewer moths at lights at night, fewer beetles under logs, fewer bees on flowers, and fewer insects in the air on warm evenings.
The question is: why?
CHANGING FARMING PRACTICES
Over the past 40 to 50 years, farming in New Zealand has undergone enormous change, particularly in the lowland and plains regions.
Where farmland was once a mixture of small paddocks, shelterbelts, hedgerows, rough pasture, wetlands, swamps and weedy corners, much of it has become simplified and standardised. Large, uniform paddocks of ryegrass, clover, maize, fodder beet or other single crops now dominate the landscape in many areas.
As farms became more mechanised, shelterbelts and hedgerows were removed to make room for larger machinery and to improve efficiency. Wetlands were drained, gullies were cleared, and “untidy” areas were tidied up. Unfortunately, those “untidy” areas were often the very places where insects bred, fed and sheltered.
Wildflowers, native shrubs, thistles, clovers, herbs and flowering weeds provided nectar and pollen throughout the season. Insects had habitat at different stages of their life cycles – from larvae in soil and decaying vegetation to adults feeding on flowers and leaves. When these areas disappeared, insects lost both food and shelter.
Even where native bush remains, it is often fragmented and isolated, making it difficult for insect populations to spread and recolonise once local numbers fall.
THE INCREASED USE OF AGRICULTURAL CHEMICALS
Alongside physical changes to the landscape, there has also been a significant increase in chemical inputs to farming systems.
Herbicides, fungicides and insecticides are now widely used in modern agriculture and horticulture. While these chemicals are often targeted at specific pests or weeds, they do not always stay neatly within intended boundaries, nor do they always affect only a single species.
Broad-spectrum insecticides can kill or weaken beneficial insects such as:
– Native bees and honeybees
– Hoverflies
– Ladybirds
– Lacewings
– Beetles
– Moths and butterflies
– Parasitic wasps that naturally control pests
Even when insects are not killed outright, sub-lethal exposure can disrupt their ability to navigate, find food, reproduce or care for offspring. Over time, this leads to declining populations, even if mass die-offs are not obvious.
Seed treatments and systemic insecticides have also become common. These chemicals are taken up by the plant as it grows and can be present in pollen and nectar. As a result, insects feeding on the plant encounter low doses of insecticide throughout the plant’s life, even if no spraying is visible from the outside.
In areas surrounded by farmland, even properties that do not use chemicals themselves can be affected through drift on the wind, residues in waterways and reduced regional insect populations.
LOSS OF ROADSIDE AND VERGE HABITAT
Road verges once functioned as accidental nature reserves. They were often full of long grass, wildflowers, native herbs and flowering weeds. These strips of land – running beside roads for hundreds of kilometres – provided vital corridors for insects to feed, breed and move between habitats.
Today, many road verges are regularly sprayed with herbicide, heavily mown, or kept “sterile” for visual neatness and safety reasons. While understandable from a management perspective, the ecological cost has been high. These linear wildflower corridors have, in many places, become ecological deserts.
For someone driving through the countryside, this alone can make a dramatic difference in the number of insects flying at windscreen height.
LIGHT POLLUTION AND URBAN EXPANSION
Even in rural areas, night-time light pollution has increased considerably over the last 50 years.
Streetlights, security lighting, illuminated buildings and vehicle lights all attract and disorient insects. Many species use natural light cues for navigation. Artificial lights trap them in exhausting spirals, make them easy prey, or interfere with breeding behaviour.
When you live within reach of a city or town, even a modest one, light spill can affect large surrounding areas. Moths, beetles and other night insects drawn off into town environments often die without reproducing, further reducing population numbers over time.
WHY LAND ROVER USE MATTERS
The consistent observation of fewer insects on vehicles – including large, flat-fronted, non-aerodynamic ones like classic Land Rovers – is meaningful. While not a formal scientific survey, it represents a repeated, real-world data point shared by many people spanning generations.
Decades ago, a day’s drive through the countryside would require frequent cleaning of the windscreen. Today, driving the same countryside in the same type of vehicle produces almost no insect impact. That strongly suggests that there are simply far fewer insects flying in the air at windscreen height than there once were.
It is a simple but powerful indicator that something fundamental has shifted in the wider ecosystem.
WHAT CAN BE DONE TO HELP INSECTS RECOVER?
Despite the seriousness of insect decline, there is still good reason for optimism. Insects reproduce quickly, and when provided with suitable habitat and reduced chemical pressure, many species can recover surprisingly fast.
Some practical steps include:
1. Restoring “messiness” to the landscape
Allowing untidy areas around paddock edges, gullies, fence lines and tracks provides cover and breeding sites for insects.
2. Planting diverse, flowering species
A mixture of native and non-native flowering plants that bloom at different times of the year ensures a constant food supply.
3. Reducing chemical use where possible
Even modest reductions in herbicide and insecticide use, or switching to targeted and timed applications, can significantly benefit local biodiversity.
4. Changing roadside management
Allowing parts of road verges to regenerate naturally or replanting them with native flowering species can create corridors of life through otherwise barren areas.
5. Better night-light management
Using shielded, downward-facing, warm-coloured lighting and switching off unnecessary lights at night reduces disruption to nocturnal insects.
6. Creating insect refuges
Piles of timber, leaf litter, compost heaps, native shrubs, ponds and unmown areas allow insects to shelter and complete their life cycles safely.
7. Greater awareness in rural communities
Encouraging discussions about insects in farming and rural networks helps shift attitudes from “pest only” to “essential part of the system.”
None of these measures require the end of farming or modern life. They simply require a shift in perspective and a willingness to allow a little wildness to return.
CONCLUSION
The clean windscreen of today’s rural drive is not merely a coincidence. It is a visible signal of a quieter countryside, one that has lost much of the small life that once filled the air. While multiple factors have contributed to this change, the simplification of landscapes and the widespread use of chemicals in modern agriculture stand out as key drivers.
Yet this is not an irreversible path. With thoughtful changes in land management, chemical use and habitat restoration, insect populations can rebound. In doing so, they will strengthen not only the natural environment, but the entire web of life that depends on them – including us.
The real question is no longer whether windscreens used to be dirtier.
It is whether we are prepared to allow the countryside to become alive again.
Sprays are used by horticulture and foresters. Around vineyards and other crops, an insecticide Karate is used. Aptly named it is lethal killing everything in its path. Yet it’s approved and legal to use.
As a trout fly fisherman, I’ve noticed evening mayfly and caddis fly hatches on rivers are now almost non-existent. Yes, there has been a big, big decline in insects banging into and being squashed on car windscreens after dark in country areas.
Are these apparent declines in numbers of wild creatures symptomatic of an ailing and declining ecosystem?
Agencies such as council environmental sections, and the Department oif Conservation and Fish and Game should be concerned, but they are silent.
These declines in numbers of insects and other wild creatures are definitely symptoms of an ailing and declining ecosystem. This problems was famously bought to the fore when the book “Silent Spring” by Rachel Carson was published in 1962 400 pages. There have been other books since but the big corporates who make big money constantly spin fairy tales about how harmless their products are. It’s a tragedy unfolding, the big corporate’s have the most money and blackmailing Government regulators is common.
If readers are interested in how Big Corporate buy and manipulate Science an excellent read is “The Monsanto Papers – Corruption of Science and Grievous Harm to Public Health” by Gilles-Eric Seralini and Jerome Douzelet First published 2020 162 pages, ISBN: 978-1-5107-6763-8. Class Actions have cost Bayer who bought out Monsanto $13.6 billion with more class actions in the pipeline. Bayer still market the herbicide (weed killer) Roundup to small gullible countries like NZ even though 30 years of research show it causes cancers, liver and kidney disease.
Karate is classed as lethal to aquatic life. Diazinon, DDT’s replacement and widely used, is classed as “lethal to aquatic life and water birds” which should concern agencies like DoC and Fish and Game.
The controversial pest poison 1080 originally developed as an insecticide, is lethal to not only insects but birds and animals too. Who is the major user? Answer – DoC.
I googled about Karate. AI says “Karate insecticide, which contains the active ingredient lambda-cyhalothrin, has significant negative environmental effects, most notably that it is very toxic to aquatic organisms and poses a risk of long-term adverse effects in the aquatic environment. “
I see the usual idiots are trying to blame Climate Change/Disruption/Warming for the demise of insects. With temperatures easily varying by 20°C during a single day, it is hard to comprehend how 1.5°C increase in local temperature AVERAGE could have such profound effects to kill about 90% of all insect life.
Incredibly powerful this Climate of ours, is there absolutely nothing we can’t blame it for?
Rather let’s ask DOC, EPA, Farm and Forestry managers, Territorial Authorities and the likes of the NZTA why they insist everything must be sprayed, fumigated and infused with noxious chemicals that linger forever in the food chain.
The same research suggesting insects suffer consequences to behaviour and reproduction when exposed to these products – the same chemicals that are still in our food when we consume it. Are we seeing similar effects on the human population? You may well ask…
A good question Charles. As a kid in the ’50s, we never had things like ADHD (Hyperactive Kids yes), Asthma (almost unheard of), Autism, Sexual Identity Issues nor obesity. Conduct Disorder was easily dealt with with a strapping, eating disorders what? Anxiety – yes if we’d done something wrong.
But we see now human reproduction rates in the OECD falling off a cliff, and all manner of psychiatric/psychological illnesses that we had never even heard of. Then again we were healthier, withstood things like measles and mumps without it descending into a national panic. Chickenpox was actively encouraged with parties at infected households. We had polio and smallpox to deal with, but the immunisation programs then fortunately saved us. TB was dealt with – but I think maybe I had just 3 or 4 different innocultations as a child – now its 14 different vaccines covering over 20 different possible diseases.
Is there any consequence to this? Any side effects? You be the judge!
You probably know the answer to your questions, it goes right back to the Bilderbergs, the World Economic Forum (WEF), Bill Gates and other rich philanthropists.
Not to mention the devastating effects of 1080 poison on native insects, as proven by DSIR scientist Mike Meads in the early 1990’s.
Well done and scientifically accurate, whilst the topic is so disturbing. Those of us who read The Silent Spring all those years ago feel particularly sad that corporate greed and a preoccupation with economic growth at all costs have been so influential in our plant’s spiral to self destruction.
The real cause of environmental problems that no-one wants to accept is CONSUMERISM.
We have all been manipulated by sophisticated advertising and marketing propaganda to be mindless consumers of products and services we do not need and cannot afford.
Planned obsolescence is intentionally built in to all modern consumer products to ensure that they will be disposed of and replaced instead of maintained and repaired.
Foods have been altered to improve appearance, shelf life and taste at the expense of nutrition.
Fiat currency is created from nothing and loaned to enable consumers to buy more. Their incomes have been replaced by debt.
It is not just the survival of the insects that is in jeopardy.
The survival of our species is as well because of the mental and physical health consequences of consumerism and also the declining birth rate that is now 50% of replacement in many western nations.
We call our species Homo Sapiens but we are not very smart or wise because most of what we are doing is likely to contribute to our demise.
Since 1970, our planet has seen:
* the human population increase from 3.5 to over 8 billion (forecast to reach 10-11 billion by the end of this century .. that’s a 25-30% increase over what we have right now)
* more than a 60% reduction in global wildlife
* over 93% of the mammalian biomass is now either human, or the animals we farm to feed ourselves
* over 75% reduction in global insect biomass
* we’ve now altered more than 75% of the planet’s land area (which is most of what we can readily alter)
Bottom line is .. we seem to be on an unstoppable path towards our own demise .. sadly, taking down most of the rest of the planet’s biodiversity with us .. and the solution is not obvious.
Overt attempts to tackle the issue are untenable – we would quickly label those as genocide, or something similar.
There are initiatives afoot to covertly curb human population growth .. but the people who try to bring these to public attention are labelled conspiracy theorists.
A falling birth rate in the western world is no solution .. because that’s being offset by population growth elsewhere .. so we’re seeing an accelerating imbalance in the global population amongst those of different religious faiths .. which is simply achieving where past wars have failed.
Most of the advanced technologies we are developing are just money-making schemes only serving to accelerate the problem .. some threaten to do so massively.
Any other initiative in this space quickly gets perverted by our 3 great human fallibilities (greed, the desire for power and control, and the drive to procreate) .. with most just becoming new ways for the global elite to make money at ever-increasing rates.
The initiative we call climate change, for example, is being used to scam the population in ways that take such scamming to hitherto unforeseen new heights.
Groups of whimsical idealists piss about trying to get us to change behaviours around this or that .. but really, they’re just shuffling deck chairs on the titanic.
I once sat in a taxi with a Sikh Indian talking about what caused the population explosion that saw the population of India go from less than 500 million around 1950 .. to now over 1.4 billion. He said the answer was simple .. western medicine around childbirth. People thought we fixed a problem .. but really, we just replaced one problem, with a much, much bigger one.
Unfortunately, I cannot propose any tenable solutions .. but I do think we’re screwed if we can’t even just simply agree what is the elephant in the room .. and the root cause of the real problem .. instead of just focusing on symptoms.
In the meantime, the best cause for optimism in our individual lives .. is the fact none of us are here forever. That’s not selfish thinking .. it’s just a pragmatic, bare-faced fact. So all we can do .. is make any adjustments we can, to minimise our individual contribution to the problem (I try to do something good for the planet every day) .. and otherwise, strive to live the best lives we can.
It would be grandiose thinking .. if any of us thought we could do much more than that, towards addressing the issue.
Having said that .. as Einstein told us .. we cannot fix our problems using the same thinking we used when we created them.
That’s why we must stop doing stupid shit like flying about in helicopters, indiscriminately aerially applying thousands of tonnes .. of a WHO Class 1A ecotoxin .. that kills anything that consumes oxygen .. across millions of hectares .. of otherwise pristine bush and backcountry .. repeatedly, year after year.
That’s not doing something good for the planet .. it’s simply trying to fix a problem using the same flawed thinking that was used to create it.
And that’s pretty dumb.