Insectocalypse and Its Solutions

Financial Times (paywall):

Turns out ecologists and entomologists around the world have been warning about declining insect numbers for years. The culprits are climate change, habitat loss, light pollution, intensive farming, pesticide and fertiliser use. But it’s a struggle to get people to act. After all, we humans have a complicated relationship with our six-legged fellow Earth dwellers.

Who can forget the horror of Kafka’s Metamorphosis, where a travelling salesman wakes up one morning to find himself transformed into a bug, or the morality tales of the Victorian age that saw naughty children turned into insects? Up close, even the face of a butterfly or bee is disturbingly alien. Maybe we’ve been “othering” insects to oblivion. 

Yet our own existence depends on a thriving insect world. Studies show that where more insect species are present, pollination is more reliable and resilient. As Dave Goulson, professor of biology at the University of Sussex, points out in his book Silent Earth: Averting the Insect Apocalypse, about three-quarters of all crop types grown by humans require pollination by animals, the vast majority by insects.

“We could not feed the global human population without pollinators,” he writes. It’s not just about bees and butterflies, the poster children of the pollinator world. Other, less photogenic pollinators such as hoverflies, moths, wasps, soldier beetles and earwigs are also showing declines. Several of these species don’t just pollinate. They also eat the pest insects that ruin crops. A UK parliamentary report in March this year noted that, internationally, the economic value of pollinators has been estimated to be worth over £134bn to agricultural markets.

Already, in the apple and pear orchards of south-west China, depleted populations of pollinators have forced farmers to hand-pollinate their trees, carrying pots of pollen and paintbrushes with which to individually pollinate every flower. If it sounds labour-intensive and time-consuming, that’s because it is.

But try convincing, for example, beachgoers on Misquamicut State Beach in Rhode Island that insect numbers are plummeting. In July this year, they were swarmed by hundreds of thousands of dragonflies. The problem is that data on insects is patchy and varies not just by geographical region and time of year but also by species. Interpreting it is fiendishly difficult. There is no unified global monitoring system for insects. Their sheer number makes it impossible; insects account for the majority of species on the planet. We’ve named about one million of them but there are millions more we don’t know about and whose role in balancing ecosystems remains a mystery.

Which brings us to the point of a fly, or a dung beetle for that matter. Without them we might be swimming in excrement and wondering what to do about rotting animal carcasses. “Probably, we’ve lost [insect] species that have not yet been named,” Goulson says. Perhaps alone among the sciences, entomology relies heavily on volunteers and “citizen scientists” for data collection.

People like Roger Morris in the UK, who loathes the term citizen scientist, preferring ‘‘community scientist” instead. Morris is a retired ecologist and estuarine geomorphologist, but his passion is the hoverfly, an insect often mistaken for a wasp or bee. It’s one of nature’s most important pollinators and some species of hoverfly are now endangered in the UK and Europe. Since 1991, Morris has volunteered as joint organiser of Britain’s Hoverfly Recording Scheme and co-authored a book on the species. 

Cornell University:

Hoverflies:

Common Names

• Hover Fly
• Syrphid Fly

Relative effectiveness

Each larva can consume up to 400 aphids during development, and therefore reduce damage to some plants. When syrphid larvae are abundant, they may reduce aphid populations by 70 to 100%.

Argonne National Lab:

The two studied solar sites were planted with native grasses and flowering plants in early 2018. From August 2018 through August 2022, the researchers conducted 358 observational surveys for flowering vegetation and insect communities. They evaluated changes in plant and insect abundance and diversity with each visit.

“The effort to obtain these data was considerable, returning to each site four times per summer to record pollinator counts,” said Heidi Hartmann, manager of the Land Resources and Energy Policy Program in Argonne’s Environmental Sciences division, and one of the study’s co-authors. ​“Over time we saw the numbers and types of flowering plants increase as the habitat matured. Measuring the corresponding positive impact for pollinators was very gratifying.”

By the end of the field campaign, the team observed increases for all habitat and biodiversity metrics. There was an increase in native plant species diversity and flower abundance. In addition, the team observed increases in the abundance and diversity of native insect pollinators and agriculturally beneficial insects, which included honeybees, native bees, wasps, hornets, hoverflies, other flies, moths, butterflies and beetles. Flowers and flowering plant species increased as well. Total insect abundance tripled, while native bees showed a 20-fold increase in numbers. The most numerous insect groups observed were beetles, flies and moths.

In an added benefit, the researchers found that pollinators from the solar sites also visited soybean flowers in adjacent crop fields, providing additional pollination services.