Pesticides: Insecticides, Fungicides & Herbicides.

Nairn beach on a quiet day.

Walking Through the Week.

We’ve had a mixed wintry week of stillness with sparkling sunshine one day and raw thawing slush the next. And now storm Christoph has unleashed his fury dumping cold rain and whipping up gales taking a meteorological battering ram to our island. The hives are strapped down and all 9 colonies are safe inside. On a still day, an ear to the brood chamber wall and a gentle tap on the side produces the soft reassuring reply of the winter cluster doing what it is primed to do; huddling close and eating stores to keep warm.

Sunday was the perfect day; the lull before the storm. On an eye piercingly bright sunny morning when the temperature rose to 4 degrees Celsius and a few bees ventured out around noon, so did I. I’ve never seen so many people on Nairn beach before, not even on a summers day. The beach is packed with lone walkers, couples, families, dogs and a couple of horses. In the distance, the thin dark shapes of walkers resembling a Lowrie painting cover the horizon and every inch of sand bears testimony to the traffic.

Sea buckthorn still bears its orange berries and blackbirds are feasting. A perfectly straight line of oyster catchers flies close to the water, a black and white band that suddenly coalesces to form a flock as it reaches a spit of land to descend and settle. Children are shrieking in delight, and a very small girl in a pink hat and dress with a raspberry coloured coat and matching wellies is exploring the shoreline. She wades out as far as she can and splashes from the safety of daddy’s side. A pre-teen boy in a winter jacket and summer shorts paddles with bare feet a little further out calf-deep in the bitterly cold North Sea. Twin girls in matching bobbled blue and white beanie hats and winter jackets are completing the moat for the elaborate sand castle they’ve constructed on the wet sand near the shore margin.

We walk as far as we can before a wide channel of water cuts off the rest of the East Beach to walkers without wellies. We sit in the sun on a clump of marram grass to ear a cereal bar and sniff the sea air before the weather changes. Officially forecast to cloud over and rain in the afternoon, the weather doesn’t let us down and we feel the chill cold as the sun retreats and dark rain clouds sweep in from the west.

Another local walk reveals a spotted woodpecker drumming its territorial message on the 15th in a sycamore tree not far from the road in a nearby hamlet. I’ve never seen one before actually drumming and I’m fascinated. Sadly, it is too difficult to get a good photograph. Last year, I recorded the first woodpecker drumming a week later on the23rd.

Have you ever actually seen a mole at work? I’ve seen one appear above ground only once during its excavation work. This week I noticed the ground heaving along the farm track on my way to collect eggs a mile from home. I watched a while as the earth pile got larger to perfectly match the line of enormous molehills running the length of the farm track. I didn’t catch a glimpse of the earth mover.

A letter from Elliot, the hogweed bashing boy in the yellow jacket, arrived prompting me to get out my microscope and do some detective work. He asks me what animals live in hogweed, and how many bees do I have altogether. I can answer the second question but I’m not sure about the residents of hollow hogweed stems in winter so I collect a piece for dissection. Not a massive bit of research in only examining one stem but I find a single tiny white almost transparent 8-legged mite that I hope will interest Elliot. I hope that he will feel inspired to do some investigations himself so I look out a spare jeweller’s loupe and insect book to give him.

Pesticides: Insecticides.

Lethal doses of insecticides do what they say on the tin; they kill insects outright and indiscriminately. Honey bees get caught in the crossfire of the war against crop pests. The lethal dose (LD50) varies with each chemical. The LD50 kills 50% of adult bees. The LD50 of Thiamethoxam, the neonicotinoid to be used on sugar beet, is 4 billionths of a gram according to scientist Dave Goulson, and one teaspoonful is enough to kill 40 tonnes of honey bees. These chemicals are neurotoxins targeting the brain and nervous system of insects.

Sub-lethal doses of neonicotinoids are known to affect the cognitive behaviour of honey bees impacting negatively on foraging and memory, and the ability to navigate the return journey back to the hive. Muscular activity is impaired affecting flight and thermoregulation. Waggle dancing is also impaired leading to unsuccessful foraging which can cause starvation and colony collapse. Contaminated pollen is fed to brood. These toxic chemicals cause immunosuppression which is perhaps one of the most alarming side effects. Combined with varroa and deformed wing virus this is very bad news for a colony. Not to mention the synergistic activity that takes place when beekeepers use heavy duty acaricides, such as Apistan and others, to kill varroa. Toxins are attracted to wax which is lipophilic so the brood nest comb acts as a poison reservoir holding onto the contaminating chemicals. Beekeepers are responsible for increasing the toxic load when they use these varroa treatments.

Fungicides.

Contrary to what some people may think, fungicides are not benign and they are also harmful to honey bees but in a different way from insecticides. Fungicides affect basic cellular processes so every body cell in a honey bee may be affected. Nucleic acid and protein synthesis are adversely affected alongside the structure and function of each cell which means that cells may not grow and regenerate as they should. Fungicides targets ATP (adenosine triphosphate) so the production is reduced. This chemical is essential for getting energy to each cell and it is crucial for normal cell function.

Fermentation Factory.

There are lots of useful good fungi in a honey bee colony. It is teeming with them. Fungi are everywhere and honey bees pick some up whilst foraging. If you think about how honey bees preserve pollen with yeasts and enzymes to make fermented bee bread, and how important this stored pollen is, you can easily imagine the impact of fungicides on these good guys. Not only is nutrition affected, but the good fungi is no longer there to defend against the pathogenic fungi that cause chalkbrood, stonebrood and nosema for example.

Herbicides.

Herbicides usually target a plant enzyme so that its cellular function is impaired and it dies. It targets specific plants and spares crops. Sometimes they are designed to affect the growth hormone auxin.

Debate.

This week, I listened with interest to a well balanced debate between scientist Dave Goulson, and Minette Batters, President of the National Farmers Union, farmers, an agronomist, and Janet Hughes civil servant.

The Bumblebee Conservation Trust Statement.

” The Bumblebee Conservation Trust is extremely disappointed to hear that the neonicotinoid Thiamethoxam has been granted a derogation for emergency use on sugar beet crops in England
during 2021.  Thiamethoxam has been shown to cause harm to bees and other pollinators, which led to the use of neonicotinoids being banned for outdoor use in the EU in 2018.
We fully support these restrictions, and our position remains that we do not want to see harmful pesticides being used, that put bumblebees at risk.
Risks to Bumblebees in the case of non flowering sugar beet is through the leaching of the active ingredient from the crop into wildflowers in and around the field margins.
Neonicotinoids are well known for their environmental mobility, and can cause harm to other animals, such as soil invertebrates and aquatic life.”

The Future.

Farmers don’t want to kill non-target insects and they are going to need a lot of support finding alternatives to neonicotinoids. A good way forward, apart from great changes in agriculture, may be changes in consumerism that mean less food waste, and eating more locally produced food with fewer imported goods, especially out of season food.

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