What Are Neonicotinoids?
What Are Neonicotinoids?
by Ida Livingston of Davis City, IA
It has been several years since our bees have done really well. The last year that they did (2021) broke all the records. One hive alone was so large that the boxes stacked around 8 ft tall just to contain the hive. We had several excellent hives but it was by far the largest hive that my husband Khoke had ever had.
For all of the honey it produced, for the hundreds of thousands of workers in it and its overactive queen, this hive died out entirely that winter, as did almost all of our hives. They did not starve or freeze out. What happened? They were so happy, healthy, and thriving.
We may not actually ever know. CCD (Colony Collapse Disorder) is not entirely understood and there are many rising factors that oppose our pollinators. Among these stressors are Varroa mites, disease, hive beetles, wax moths, RF EMF radio waves (like cell phone and Wi-Fi frequencies), and now systemic pesticides, largely Neonicotinoids. CCD has not been proven to be caused solely by any one of these as research is inconclusive so far. At least no one is saying if they do know.
What are Neonicotinoids?
Neonicotinoids are a group of pesticides that became available in the mid 1990’s. They are extremely effective, and unfortunately, popular. They are a systemic insecticide that renders the entire plant toxic to invertebrates (insects, arachnids and more). Technically they can be toxic to mammals as well but they’re usually applied in doses low enough that we do not exhibit symptoms. The long-term effects have not been fully researched.
This pesticide is a neurotoxin that attacks the nervous system. Field applications leave plants with pesticide residues ranging from 20 ppb (parts per billion) to over 100 ppb, but ornamental plants in landscaping and parks can receive much higher doses that can range from 300 ppb up to 12,000 ppb. What do those numbers mean? Well, 200 ppb can kill a hive outright, but as little as 20 ppb will kill honey bees who have a chronic exposure. This is an extremely potent group of insecticides.
Chronic exposure is when an insect has repeated sub-lethal encounters with the neonicotinoids. It is a relatively low dose which doesn’t kill them outright – it does poison them but they will often survive it. Surviving means they are still alive but they will have repercussions. They probably won’t bounce back to 100%. Chronic exposure to pollinators causes sublethal symptoms, such as impaired development in larvae and the adults suffer from impaired cognitive function, motor activity, and communication. They can struggle with memory; remembering where home is or food sources are, retaining information and communicating with other bees. It can alter their sucrose (sugar) sensitivity.
The first neonicotinoid introduced was imidacloprid in 1994. There are now at least 7 neonicotinoids on the market, imidacloprid, acetamiprid, thiamethoxam, clothianidin, dinotefuran, thiacloprid, and nitenpyram. Thiacloprid is no longer used in the US, but is still sold in other countries. Acetamidprid has the shortest half-life, in the soil at less than 2 weeks. Clothianidin has the longest half-life which can last over 3 years in some soils and is also one of the most frequently used neonicotinoids. Nitenpyram is commonly used in veterinary medicine to combat fleas and other pests. You can look on the labels of your garden supplies to see what the active ingredients are to determine if there any neonicotinoids in them.
Popular Appeal
Neonicotinoids were developed as an alternative to organophosphate and carbamate insecticides. These were families of insecticide that were seemingly much more harmful to vertebrates. Neonicotinoids are also so incredibly potent that it takes relatively low doses to make them effective and many have a long half-life, meaning the lingering residues.
A seed coated with a neonicotinoid insecticide can render the whole plant that grows from that seed toxic, toxic enough to deliver sublethal to lethal symptoms in pollinators when the plants bloom. That is a long effect for a little bit of insecticide. Most commercial field crops have their seed coated with this; even garden seed can come to you treated with this insecticide to protect the seedlings as they grow.
Seating myself comfortably in The Devil’s Advocate chair, let’s talk about some realities. This family of systemic sprays are often sprayed on commercial orchards that – yes – rely heavily on pollinators. But insects such as the rosy apple aphid scar and deform the fruit at such an early point that the trees must be sprayed or receive a soil drench in time to be effective over bloom. This will impact any pollinators. After they bloom, it is too late; other insecticides will not work against this aphid.
Deep inside most people is a Snow White who wants that big, beautiful, (poisoned) apple, reaching past all the misshapen, scarred, and otherwise blemished ones to get it. We want that perfection at all cost. And there is a cost.
Aesthetics aside, there are some very real world problems too. We have invasive insects making certain crops nearly impossible. The Emerald ash borer is killing off the ash trees. The maple trees are dying off in the northeast from the invasive Asian longhorned beetle. The sugarcane aphid blew north from the sugarcane fields in the Caribbean to infect the millet and sorghum crops in the American South, making these nearly impossible to grow. Farmers are facing very real threats to their land-based livelihoods and have had some hard decisions to make.
Recently, someone I knew was looking into buying bulk maple syrup and asked if buying organic maple syrup was a gimmick. How can maple syrup not be organic? Well actually, there can be a difference. There are places where the presence of the Asian longhorned beetle has such a population density that untreated trees can all die. Generational maple syrup producers face the loss of a heritage business and all their trees and may feel that they need to treat the trees with a systemic chemical to try to save them. There are also de-foaming agents used during the cooking process.
Many Southern sorghum producers have begun using Sivanto; a systemic non-neonicotinoid insecticide used to successfully combat the sugarcane aphid. The active ingredient is flupyradifurone, posing all the same risks as a neonicotinoid, just a different chemical. This invasive aphid has made raising untreated sorghum extremely difficult.
Primary and Secondary Problems
The most obvious problem with systemic sprays is the threat to pollinators. Honey bees are the most noticeable casualty, mostly because the American consumer thinks that their greatest contribution is honey. Honey bees are credited with pollinating about $15 billion worth of crops every year. They produce a little over $1 billion of honey annually.
Honey bees regularly forage within a 2-mile radius of their hive, but they can and will travel much farther than that. How many hives have a chance at finding a field of neonicotinoid treated crops within that range? Worse however, are the landscape plants. These are often sprayed at significantly higher concentrations (lethal), well above levels tolerated by our pollinators.
Honey bees are only one of several thousand non-target species that can be affected by systemic agrochemicals. There are over 3,000 species of bees in the United States, most of these are native. The honey bee is not native. Pollinators like Mason bees (over 200 species), pollinate early blooming fruit trees. This is important not only for orchards but also the wild fruit, nuts, and berries that wildlife rely on.
Bumblebees too, face heavy casualties. There are many species and they are an important pollinator for a wide variety of flowers both wild and cultivated. Poor pollination of wild plants and trees has a trickle down impact on wildlife. Bumblebees don’t have the large colonies that a honey bee has and can feel the impact of worker bee losses quickly.
Part of the overall problem is neonicotinoid exposure to nontarget plants. Wind causes spray to drift, chemigation pipes can leak, contaminated runoff follows the waterways, even the talc used to keep coated seed from clumping can get dumped off field, contaminating the site with its neonicotinoid residues.
Among the non-target plants affected by spray drift are the highly perfumed milkweed that grows along field edges, ditches, and fence rows. Milkweeds host monarch butterfly larvae. The Eastern Monarch overwinters in Mexico, andtheir numbers have dropped 80% in the past 20 years. The Western Monarch, which overwinters in California, has dropped 74% in that time as well. Since the larva feeds on the plant itself, the lethal dose for them is lower than a pollinator. Granted, their decline is not solely due to systemic sprays, there are many other contributing factors. This includes the aggressive mowing of their habitat and the task of navigating well over a thousand miles in migration, feeding wildlife and automobile radiators along the way.
Another factor of concern is contaminated waterways. Here in the Midwest, there were nine waterways tested for neonicotinoid contamination. Each waterway was found to have multiple neonicotinoid chemicals detected. In California 89% of flowing waterways are contaminated by neonicotinoids.
The half-life of these chemicals is significant in comparison to many other chemicals. Depending on your soil type, heavier clay bases hold both nutrients and chemicals captive longer than sandy soils. Neonicotinoid field applications can have a residue half-life of one year to over 3 years. Woody plants, trees, shrubbery, berry bushes, and ornamentals can have a half life of as long as 6 years from a single application. Repeat applications can have a cumulative effect.
Where from here?
In light of increasing awareness and the public debate about neonicotinoids, new systemic chemicals have emerged. They slip past the bad publicity that the word neonicotinoid can arouse, but they pose the same threat. A couple of examples are flupyradifurone and sulfoxaflor. New chemicals just mean new problems, and often, just the same old problems.
The Xerces Society for Invertebrate Conservation promotes Integrated Pest Management (IPM) ideology. This supports organic principles but does not cut out the possibility of chemical use entirely, just as little as absolutely necessary. “Necessary” is up for interpretation here.
Anyway, IPM encourages careful attention to good timing for planting, utilizing trap crops, selecting pest resistant varieties, monitoring pest populations, and encouraging predatory/parasitic insects that target undesirable insects/larvae. Insecticides would be used as a last resort, and even then would have to be carefully selected so it only affects the targeted pest.
There are quite a few natural products these days that assist the home gardener. One can even handpick the cabbage loopers or potato bugs down the row of a backyard garden. But when you are looking at a 250+ acre field of any singular crop, commercial farmers are obviously searching for more cost/labor efficient alternatives. Broad spectrum insecticides are the fix-it and forget it solution that most turn to.
Acknowledgments
Several years ago in a phone conversation with my father, I first became aware of the neonicotinoid threat to bees. As a beekeeper who deals with the mysterious colony collapse disorder in his bees on occasion, his frustration leads him to his Agricultural Extension Office and the phone numbers of University Ag departments in his search for answers.
Not long afterward, I came across an article on neonicotinoids in the Prairie Moon catalog. They sell native wildflower seed here in the Midwest and boldly declare themselves neonicotinoid free. Their catalog had a summary of the neonicotinoid threat to pollinators. The Prairie Moon website has a link to the Xerxes Society website where one can download the free 84 page pdf booklet How Neonicotinoids Can Kill Bees; The Science Behind the Role These Insecticides Play in Harming Bees, 2nd edition. The bulk of the information in this article is sourced from this report. It is a great read for anyone interested in more information, as they have much more available than I could hope to share.
Going Forward
As we go forward, although there is little that can be done about what others do on their own property, there are a few things we can do. We can post “Do Not Spray” signs on the road edges of our property to keep county workers from spraying on our stretch of roadside. We can research the seed we buy, sourcing only vegetable and grain seed that is untreated.
Some states like Iowa, have an Apiary Registration. A beekeeper can register the location of their hives. Farmers within a mile of these hives may not spray their fields with insecticides within the hours 8am-6pm, the peak flight hours for your bees. These hives are registered on a Sensitive Crops registry. You may need to communicate with some of these farmers about the hives. Being polite and respectful in these conversations helps get cooperation. The law is only on your side for what you can prove. Don’t bring out the jack donkey in people if you can avoid it.
Back at home, we can plant pollinator friendly plants in our home spaces where they have a safe place to feed. We can also support local growers who grow their food mindfully. We can choose something different from Snow White and select food for more than beauty.
Resources
How Neonicotinoids Can Kill Bees
https://www.xerces.org/publications/scientific-reports/how-neonicotinoids-can-kill-bees
The Xerces Society for Invertebrate Conservation
https://www.xerces.org/
1631 NE Broadway Street, #821
Portland, OR 97232
Telephone: (503) 232-6639 Toll Free number: (855) 232-6639
Prairie Moon Nursery: We are Neonicotinoid Free
https://www.prairiemoon.com/the-impact-of-neonicotinoids.html
Toll Free / 866-417-8156 Local / 507-452-1362
Iowa Department of Agriculture and Land Stewardship: Apiary
https://iowaagriculture.gov/entomology-plant-science-bureau/apiary
Iowa Department of Agriculture and Land Stewardship
Wallace State Office Building, 502 E 9th Street, Des Moines, IA 50319
515-281-5321