The science of insect population collapse
Last week, an article in the scientific journal Biological Conservation made waves around the world. Its authors, who reviewed 73 studies of insect populations, claimed they found “dramatic rates of decline that may lead to the extinction of 40 per cent of the world’s insect species over the next few decades”, triggering “wide-ranging cascading effects within several of the world’s ecosystems”. Headlines warned of an oncoming “insect Armageddon”. Google searches for the phrase “insects dying” jumped tenfold in a week.
Entomologists are not used to this kind of attention. The study of bugs is not the most glamorous or media-friendly of the scientific disciplines. When journalists do come calling, it’s often in response to a study that’s been blown out of proportion, or with a less-than-rigorous scientific basis. They have spent a lot of time recently talking down excitable people.
With the caution typical of researchers, they invariably start by mentioning the limitations of Biological Conservation’s article. Its authors mainly looked at studies conducted in Europe and the United States, making it difficult to infer worldwide conclusions. They found their 73 studies by searching “insect* + decline* + survey” in the online Web of Science database, potentially excluding studies that found evidence of increasing or stable insect populations. Sweeping conclusions such as “all the world’s insects are dying” can’t be drawn from one paper review, no matter how rigorous.
But none of the entomologists speaking on this study dismiss the Biological Conservation article as junk science. While it’s not a one-stop confirmation of the oncoming insect apocalypse, it confirms what smaller, single-location studies have found in the past. Several entomologists argue that the article’s greatest value lies in the gaps it revealed: the studies it couldn’t draw on, the research that was never funded.
Dr Manu Saunders is a postdoctoral research fellow at the University of New England, specialising in insect ecology. She says that while the attention on her often-neglected field is welcome, the media’s treatment of the Biological Conservation article – and scientific issues in general – obscures an even more serious problem: we don’t know nearly enough about the world’s insects to tell if we’re killing them.
“Last week it was ‘Insect Armageddon!’ This week it’s, ‘Oh, look, Scott Morrison’s done something’,” Saunders tells The Saturday Paper. “I think this review has shown us what people don’t understand about how science works and how research is done. Insects are a lot harder to study than other animals, and even plants. There are funding gaps, they have different life cycles and generational gaps than what most people are familiar with. It makes it almost impossible to definitively pinpoint whether declines are happening or not.”
That ignorance is especially acute in Australia. The Biological Conservation article only drew on a handful of studies conducted here, largely because there aren’t many studies from which to draw.
“Even if we start now, it’s going to take us 20, 30 years to identify whether our insects are actually declining and why,” Saunders says. “Only 25 per cent of Australia’s native insect species are described. The other 75 per cent, we don’t know anything about them. Where they live, what they eat, how their life cycles work, anything.”
The president of the Australian Entomological Society, Dr Philip Weinstein, agrees. “We have a serious lack of long-term monitoring studies in this country. This is not a new issue, but it is timely to highlight it.”
Dr Tanya Latty is a research and teaching fellow in entomology at the University of Sydney and a member of the Australian Entomological Society education committee. When she arrived in Australia 11 years ago, Christmas beetles were commonplace in the summer. Now, they seem to have all gone, but there’s no hard data to draw on to figure out why.
“Nobody’s been collecting that information. We can’t say if it’s just a dip, or if there’s a true decline that we’re just noticing now,” Latty says. “There’s just no way we can know that right now.”
A common complaint from entomologists and insect ecologists is that media attention – and the funding for research and preservation that comes with it – too often goes to “charismatic” threatened animals. Since 2016, Australia has spent nearly twice as much money trying to breed two pandas at Adelaide Zoo as it has on the Threatened Species Recovery Fund.
One of the few Australian works cited in the Biological Conservation review was a 2011 article in The Australasian Beekeeper, by beekeeper Jeffrey Gibbs. Gibbs interviewed beekeepers in Gunnedah, Dubbo and Deepwater, who noticed significant bee losses after letting their hives pollinate neonic-treated crops.
“I’ve been a beekeeper for more than 40 years,” Gibbs tells The Saturday Paper. “I know most of the beekeepers in Australia. Bees are our canary in the coalmine. Seven out of 10 of them are dead, and the others stopped singing 10 years ago. Until neonics are banned in this country, we haven’t got a fucking hope.”
Neonics, or neonicotinoids, are a relatively new kind of insecticide targeting the central nervous system. Developed for commercial use in the 1990s, neonic-based insecticides are now used on a wide range of crops, from cereals to canola to cotton to fruit. A variant is used to kill ticks on household pets. Crop seeds are sprayed before planting, rendering the plants themselves toxic to pests.
It also makes those plants toxic to bees. A meta-survey of more than 1500 studies by the European Food Safety Authority in 2018 concluded that “most uses of neonicotinoid pesticides represent a risk to wild bees and honeybees”. Neonics have been banned in the European Union, Britain, and several US states and Canadian provinces due to the threat they represent to pollination.
While Woolworths, Coles, Mitre 10 and Bunnings pulled neonics in 2018 following a public outcry, Australia’s chief agricultural chemical regulator, the Australian Pesticides and Veterinary Medicines Authority (APVMA), has left the commercial use of neonics in Australia largely unregulated.
The APVMA’s official line on neonics is that “Australian honey bee populations are not in decline and Australia has robust regulatory and surveillance measures to monitor this issue”. In a report submitted to a 2014 senate inquiry into the beekeeping industry, the APVMA claimed there was a “lack of consensus on the causes of honey bee declines”, and that the science on the role of neonics remained unclear. The beekeeping industry disputes this.
Tanya Latty says the situation could be even worse for Australia’s native bees – but we’d never know, given the lack of funding to study them.
“Honeybees are managed. People are looking after them, watching where they put them, but we know so little about our native bee populations,” Latty says. “People often ask me, ‘Are they doing well?’ And I have to say, ‘I don’t know!’ Nobody really knows. If we don’t know what’s happening with their populations, we’re not going to know if something goes wrong until we just stop seeing them.”
In November, the senate rural and regional affairs standing committee began an inquiry into the APVMA’s independence after a Four Corners report in October highlighted how the regulator is primarily funded by the chemical companies it is charged with policing. Earlier this month, the committee released its final report. It “received considerable evidence that supported the view that the authority is independent”, including from farmers’ federations, agricultural associations and Bayer Crop Science. The APVMA told The Saturday Paper in a statement that “the recent senate inquiry reaffirmed the independence of the APVMA”.
The inquiry also noted those groups that took a different view. Friends of the Earth warned that the “APVMA’s assessments frequently rely solely on company data” and that the agency “has allowed thousands of tonnes of poorly assessed chemicals to enter the food chain and environment annually”. Maurice Blackburn Lawyers highlighted the case of a farmer who had contracted peripheral neuropathy after excessive exposure to an organophosphate approved by the APVMA for use on citrus farms. The National Toxics Network noted with concern that, in 2012, the federal government scrapped a requirement for chemicals to undergo periodic reapproval processes, allowing older chemicals approved using outdated science to remain on the market indefinitely.
Tanya Latty points out that banning or restricting commercial use of neonics is not a silver bullet. Bees and other insects are vulnerable to land clearing, climate change and a host of other factors. Simply banning one kind of insecticide would force farmers to use older, even more hazardous chemicals. Banning them all would cause a collapse in agricultural production, with enormous ramifications. She believes the solution lies in governments, scientists and producers working to use insecticides sparingly, intelligently and in a way that doesn’t impact crop yields.
“There’s heaps of interest from the producers’ side of things. Insecticides cost money, so if you can manage your system in a way that gives you the same or better yields, and you’re not paying the cost of insecticides, that’s a win-win,” Latty says. “People who are growing fruit or anything that requires insect pollination are very aware that if they’re using insecticides, that might impact the bottom line. It’s just a matter of our developing the tools that will actually work.”
Besides putting away the Mortein and Aerogard, entomologists have a further piece of advice for individuals worried about the collapse of the ecosystem within their lifetimes: put pressure on those in office.
“People keep asking me, ‘What can we do?’ There are little, individual things, of course, but ultimately it’s our governments that have to do it,” Latty says. “I’ve been trying to impress upon people that if you care, write your politicians and tell them you’re not voting for them unless they start doing something. They’re the only ones with enough power.”
This article was first published in the print edition of The Saturday Paper on Feb 23, 2019 as "A bug’s strife". Subscribe here.