Neonicotinoids and insects

Bees on a honeycomb
The controversy over the effect of pesticides on bees and other insects has been rumbling along for years. This is especially the case for neonicotinoids - or “neonics” - which are sold under trade names including  acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam. Imidacloprid is the most widely used insecticide in the world; you will even find it in anti-flea treatments for domestic cats. These are powerful neurotoxins, synthetic variants on nicotine, that are applied to wheat and oilseed rape seeds before sowing.

Neonics work systemically. As the plant grows, it absorbs the seed coating through its roots and the chemical spreads throughout the plant, protecting it from pests. But this also means that the toxins get into the pollen and nectar of flowering crops. This concern led to the EU banning the use of neonics on flowering crops from December 2013. However, in a pre-Brexit move, Liz Truss, then Secretary of State for the Environment, overturned this ban in central and eastern England in 2015.

There are signs of hope in that B&Q has said that from February 2018 it would no longer sell flowering plants grown using the pesticides. It claimed it was the first retailer to commit to such an undertaking.

In a recent blog Dave Goulson summarised the effects of neonics on bumblebees (https://www.soilassociation.org/blogs/2016/the-toxic-bouquet-pesticides-in-farmland-wildflowers/). Dave will be familiar to many as the author of “A sting in the tale”, a book that offers fascinating insights into the world of the bumblebee. He is a respected bee expert - Professor of Biology at the University of Sussex and founder of the Bumblebee Conservation Trust in 2006. So when it comes to bees, he knows what he’s talking about.

His research has showed that pollen and nectar collected by both honeybees and bumblebees contained all sorts of pesticides; a mixture of several neonicotinoids and a cocktail of fungicides. What was most disturbing was that the majority of these chemicals seemed to be coming from the wildflowers, not from the crop. For pollen collected by honeybees, 97% of the neonics being brought into the hives were from wildflowers, even during the flowering of the oilseed rape that had been neonic-treated. A lot of it was coming from hawthorn blossom.

It’s not known for sure how these chemicals get into wildflowers. But we know that about 95% of the neonics applied to the crop seed goes into the soil and soil water. Residues accumulate over time and leach into nearby streams. They are liable to be sucked up by flowers and hedgerow plants nearby.

Concentrations  of neonics found in bumblebee nests are higher than those that have been found to reduce nest growth and queen production, impair learning and navigation, and cause deaths. Other insects such as butterfly and moth caterpillars are also being poisoned, for if the chemicals are in the nectar and pollen then they are also in the leaves.

As Goulson says “it cannot be good for our wildlife to be chronically exposed to chemical cocktails, and in these circumstances it should not surprise us that our wildlife is disappearing at an alarming rate. What madness has led us to pollute our countryside with persistent, systemic neurotoxins?”

Comments

Post a Comment

Popular posts from this blog

Image
Nature under our noses The myth that London is a wildlife desert, especially in the centre, has been comprehensively debunked by one individual’s study of a small urban park in Peckham.  Over a six-year period, from 2011 to 2017, Penny Metal has spent thousands of hours - and taken thousands of photos - of the insects in Warwick Gardens. She found an astonishing 555 different species of insects and spiders in the park including regional rarities and one species new to the country. There really is nature under our noses, even in the capital. Warwick Gardens would usually be considered an insignificant park just a couple of miles south of Elephant & Castle. It’s a 1.52ha (3.8 acre) area between a railway line and private gardens in the heart of Peckham, in walking distance of Peckham Rye station.  Warwick Gardens, Lyndhurst Way, Peckham, London SE15 5AQ There’s a playground for young children, a space for natural play, a ball court for football and basketball...
Read more
Image
White-letter Hairstreaks in Wandsworth, Lambeth and Southwark Summary Detailed surveys of the presence of elm trees and the White-letter Hairstreak butterfly have shown that it is more widespread in the Inner London Boroughs of Wandsworth, Lambeth and Southwark than previously thought. It is present throughout the boroughs, though never in very high numbers. It is difficult to spot, and probably even now remains under-recorded. Introduction The Inner London Boroughs of Wandsworth, Lambeth and Southwark fall within the area of the Surrey & SW London Branch of Butterfly Conservation (part of the old Vice County 17 used for recording purposes). Not much is known about the distribution and abundance of the White-letter Hairstreak in these boroughs. It is an elusive butterfly, spending most of the time at the top of elm trees (its larval food plant) and only flying when it is sunny and still. It is rarely present in large numbers, and only occasionally comes down to lowe...
Read more

Butterflies under our noses

Image
Spring butterflies in south London London is viewed by many as a wildlife desert, but this is far from the truth. In fact, there is wildlife right under our noses, if we only care to look. During March and April 2017, I made visits to green spaces in Lambeth, Southwark and Wandsworth - all densely populated inner London boroughs. Some of these sites - like Stave Hill Ecological Park in Rotherhithe, Nunhead Cemetery near Peckham and Battersea Park are Local Nature Reserves. Others, like Burgess Park in Southwark, are "ordinary" urban parks. I was able to identify 11 species of butterfly in March - Comma, Brimstone, Green-veined White, Small White, Large White, Orange Tip, Speckled Wood, Holly Blue, Red Admiral, Peacock and Small Tortoiseshell.  In fact the commonest butterfly across these sites in March was the Comma Polygonia c-album , which is having a good year.  And the Holly Blue Celastrina argiolus could be seen almost anywhere where there was iv...
Read more