The extermination of 15,000 honey bees in Anglesey by council pest control officers who mistook the rare black bees for wasps is an unhappy accident. The fact it has made the news shows a society slowly coming to its senses.

Most of us get the idea that without bees and other pollinating insects, human life would rapidly collapse. Those of us who have lived long enough remember the “moth snowstorm” (the phrase is Mike McCarthy’s) that smattered car windscreens on summer nights, and worry about its absence.

Just as we awoke to the “silent spring” of toxic pesticides that erased wildlife in the 1960s, we are awaking to the probability that neonicotinoids, ingenious pesticides that have boosted agricultural crop yields over the last 20 years, are destroying insect life far more ruthlessly than the most devoted pest controller.

Last week came the latest irrefutable evidence from the world’s largest ever field trial, funded by pesticide manufacturers Bayer and Syngenta. It showed that honey bee survival was reduced by exposure to the insecticides. Another study found that bees collect contaminated pollen from wildflowers, which take up water-soluble neonicotinoids – demonstrating wider environmental contamination.

Entomologists point out that honey bees are one of the most robust flying insects. So neonics are likely to be obliterating less tough, less well-monitored insect life.

Debates have a tipping point, where one side’s entrenched position is so overwhelmed by evidence to the contrary that it becomes preposterous. Pesticide industry denials now look absurd. The extra questions that always emerge from solid science cannot be deployed as a delaying tactic for ever. Even cancer-denying cigarette manufacturers eventually twigged.

The European Union banned neonics on flowering crops in 2014, but neonicotinoids are still widely used on non-flowering crops. We need a total ban, now, to halt both the obliteration of insect life and the sabotaging of our own best interests.

Amey’s bad hairstreak day

Entered in the 2016 Woodland Trust Tree of the Year contest: the Chelsea Road elm, Sheffield. Photograph: Matt Larsen-Daw/The Woodland Trust

The white-letter hairstreak is a rare butterfly not unduly troubled by neonicotinoids because it lives in elm treetops. Instead, its population has slumped by 96% since the 1970s because of Dutch elm disease.

If the sun shines this week, find a surviving urban elm, gaze up at its top and you’ll see them – little flecks of silver, darting about. In Sheffield, you could pop down to the elm on Chelsea Road where you’ll find them too. A hairstreak colony has lived in this tree for a century or more. It will be wiped out when Amey contractors chop it down.

Sheffield city council lost the plot long ago in its massacre of the city’s trees. Council groupthink has shut down all compromise. The wailing of people such as me probably only sharpens their axes, but what the hell: dear councillors and Amey, I beg you – let this tree and its rare butterflies live. After all, it costs nothing to not chop down a tree.

Gove: into the groove?

I marvelled at turtle dove song and the mood music at a rewilding conference at marvellous Knepp Castle, West Sussex, last week. “Politicians won’t give a monkey’s about turtle doves and nightingales,” declared the tree guru Ted Green. “Knepp is not only rewilding wildlife, it’s rewilding the soil.” As he designs the post-Brexit agricultural system, will Michael Gove soon find himself swaying along?