Johannesburg - A global team of scientists have called for urgent engagement with society on the value of insects to human well-being, noting the “fate of humans and insects are intertwined”.
In two papers published in the journal Biological Conservation this month - Scientists’ Warning to Humanity on Insect Extinctions, and Solutions for Humanity on How to Conserve Insects - the authors, who include ecologist Michael Samways of Stellenbosch University, call for immediate action to curb insect extinctions.
“The current extinction crisis is deeply worrisome. Yet, what we know is only the tip of the iceberg,” they said.
Human-driven activity, causing habitat loss, pollution, invasive species, climate change and overexploitation, was “pushing many ecosystems beyond recovery, resulting in insect extinctions”.
This leads to the loss of essential, irreplaceable services to humanity, the authors warn, stating “action to save insect species is urgent, for both ecosystems and human survival”.
Little is known about the estimated 5.5 million insect species on Earth. Most insect species are undescribed - possibly as many as 80% of them - “and even for most of those with names we have no distributional or population trend data to record ongoing extinctions”.
At least one million species are facing extinction in the coming decades, half of them being insect species.
“It is not only their vast numbers, but the dependency of ecosystems and humanity on them, that makes the conservation of insect diversity critical for future generations,” the authors said.
Efforts must be made “to fully document and appreciate what is out there, and where, especially as many insect species are going extinct even before being described”.
“A major challenge now and in the coming years is to maintain and enhance the beneficial contributions of nature to all people. Insects are irreplaceable components in this challenge, as are other invertebrates and biodiversity in general.”
Despite the known factors causing, and consequences of, insect extinction, decision-makers and civil society are only now becoming aware of the scale of the problem. “Conservation efforts have largely been focused on charismatic megafauna, especially birds and mammals, with little thought on ecosystem connectivity.
“Even within insects, some taxa have been favoured, such as butterflies and, more recently, pollinators.”
Enough evidence, say the scientists, is now available that “multiple strategies work at local levels towards saving insects. We now need to expand these locally-crafted strategies globally”.
Each species represents individuals, biomass, and functions being lost, and therefore not available for other living beings. “Each species contributes a unique piece to a complex living tapestry that changes in space and time. Each species represents an unrepeatable part of the history of life. In turn, each species also interacts with others and their environment in distinctive ways, weaving a complex network that sustains other species, including us.”
As insects are a major component of the tapestry of life, “insect conservation would do well to integrate better with overall biodiversity conservation and climate change mitigation”.
“This also involves popularising insects, especially through use of iconic species, through more media coverage, and more inclusive education.”
Many solutions are now available to support insect populations at sustainable levels.
They include preserving and recovering natural habitats, eliminating deleterious agricultural practices such as the use of harmful pesticides, implementing measures for avoiding or eliminating the negative impacts of invasive species, taking aggressive steps to reduce greenhouse gas emissions, and curbing the negative effects of overexploitation of many species.
Many countries are adopting measures to avert further insect population depletions. As an example, many European countries are banning or phasing out glyphosate-based herbicides. “Solutions are now available - we must act upon them.”