Neonicotinoids and Honey Bees Dr. Mohamed 1. Abdel Megeed Chairman of Agriculture Pesticide Committee April 2016 (Egypt)
I Neonicotinods
History of Neonicotinoids Class of neuro-active insecticides Chemically similar to nicotine. In the 1980s Shell and in the 1990s Bayer started work on their development. In 1985 imidacloprid entered the market.
Beginning in the early 2000s clothiandin and thiamethoxan are in commercial scale As of 2014 about a third of US soybean acreage was planted with neonicotinoid treated seeds, usually imidacloprid or thiamethoxam.
Market of Neonicotinoids Neonicotinoids have been registered in more than 120 Counties. With a global turnover of 1,6 billion dollar in 2008 representing 24% of global insecticide market. Neonicotinoids made up 80% of all seed treatment in 2008.
As of 2001 seven neonicotinoids are in the market Common Name Company Trade name Turnover US Dollar Imidacloprid Bayer Confidor Admire Guacho 1091 Thiamethoxam Syngenta Actara 627 Clothiandin Sumitomo Poncho 439 Acetamiprid Nippon Soda Mospilan 276 Thiacloprid Bayer Calypso 112 Dinotefuran Mitsui Starkle 79 Nitenpyram Sumitomo Capstar 8
Neonicotinoids General Use Six of this group are used against agricultural pests- they are: - Imidacloprid - Thiamathoxam - Clothiandin - Acetamiprid - Thiacloprid - Dinotafuran
But Nitenpyram is used in hygiene sector against Fleas. Neonicotinoids characterized by systemic behaviour as they absorbed and translocated through the plant. Neonicotinoids are very toxic on honey bees and other pollinators as they can detected in pollen and nectar due systemic character.
Neonicotinoids use in Agriculture Seed treatments for cereals, sugar beet and oil seed rape. Treatment for turf in the amenity sector. Soil Treatment for pot plants in the ornamental sector Foliar sprays of apples, pears and range of glasshouse crops.
Imported Neonicotinoids during 2012 2015 in Egypt (Metric ton/ active ingredient) Neonicotinoids 2012 2013 2014 2015 Mean Acetamiprid 4844 8322 13322 5260 7937 Dinotefuran 2016 1008 1008 -- 1008 Imidacloprid 33039.3 15467.2 30114.6 46339.7 31240.2 Thiacloprid 1935.4 2430.7 1920 2400 2171.53 Thiamethoxam 369.6 829 5643.2 4372.2 2803.5 Total 42204.3 28056.9 52007.8 58371.9 45160.23
Chemical Properties of Neonicotinoids Most of these products are water soluble and break down slowly in the environment. The photodegradation half life of the most neonicotinoids is around 34 days when exposed to sunlight. It might take up to 1386 days to degrade in the absence of sunlight and micro-organisms.
Persistence of neonicotinoids in soil Neonicotinoid Acetamiprid Clothiandin Dinotefuran Imidacloprid Thiacloprid Thiamethoxam Half-life in soil (days) 1-8 148-1555 138 40-997 1-27 25-100
Mode of Action Neonicotinoids Neonicotinoids, like nicotine acetylcholine receptors of a cell and trigger response by that cell. In mammals, nicotine acetycholine receptors are located in cell of both the central nervous system and peripheral nervous system.
In insects these receptors are limited to the central nervous system. Nicotonic acetylcholine receptors are activated by neurotransmitter acetylcholine. While low to moderate activation of these receptors causes nervous stimulation, high levels over stimulate and block the receptors causing paralysis and death.
Acetylcholinesterase breaks down acetylcholine to terminate signals from these receptors. However acetylcholinesterase cannot break down neonicotonids and their binding is irreversible.
Basis of Selectivity Most neonicotinoids bind much more strongly to insect neuron receptors than mammals. That is why these insecticides are more toxic to insect than manuals.
While low to moderate activation of these recaptors causes nervous stimulation, high levels over stimulate and block the receptors causing paralysis and death. Acetylcholinesterase breaks down acetylcholine to terminate signals from these receptors. However acetylcholinesterase cannot break down neonicotonids and their binding is irreversible.
II Toxicity of Neonicotinods on Honey Bees
An Introduction on Bees Pollinators support the reproduction of nearly 85% of the worlds flowering plants and 35% of the global crop production. These are approximately 4000 species of bees in North America (Michener 2007) almost all of these are native. Honey bees are important for more than 15 billion U.S. dollar in crop production annually in USA.
Routes of Neonicotinoids Exposure to Bees Contaminated pollen and nectar (Irrespective of how the product is applied). Direct spray (The most obvious exposure route for bees).
Residue contact (When bees visit flowers or walk on leaves treated with foliar spray). Contaminated nesting areas (When neonicotinoids are applied to or drift onto areas of bare ground, even with fields, may contaminate nest sites for ground-nesting bees).
Exposure of bees to neonicotinoids Neonicotinoids residues in pollen and nectar are consumed by flower- visiting insects as bees. Concentration of residues can reach lethal levels in some situation. Neonicotinoids can persist in soil for months or yeas after single application.
Measurable amounts of residues were found in woody plants up to six years after application. Untreated plants may absorb chemical residue in the soil from previous year.
Toxicity of Neonicotinoids on Honey Bees * A dramatic rise in the number of annual beehive losses noticed around 2006 * A potential toxicity to honey bees and other beneficial insects even with low levels of contact. * Hazard of neonicotinoids on honey bees : Disorientation- Hampering feeding -Paralysis
* Neonicotinoids may impact bees ability to forage, learn and remember navigation router to and from food sources. * Separate from lethal and sublethal effects solely due to neonicotinoids exposure.
* Neonicotinoids are also being explored with a combination with other factors as mites and pathogens, as potential causes of colony collapse. * Bees can fail to return to the hive without immediate lethality due to sub- nanogram toxicity, one primary symptom is colony collapse disorder.
Neonicotinoids and Colony collapse Disorder (CCD) * Colony collapse Disorder is the large scale loss of honey bees * No single factor alone is responsible. * CCD Caused by multiple factors: Pathogens and parasites that work individually but protoably in combination.
* The failure of foraging bees to return to their hives has led many people to suggest that a link exists between CCD and the behavioural disruptions with sub lethal exposure to neonicotonids. * Honey bee exposed to sub lethal levels of neonicotinoids can experience problems with flying and navigation, reduced taste sensitivity and slower learning of new task, which all impact foraging ability.
Concentrations of Neonicotinoids insecticides known to cause harm when ingested by bees. Thiamethoxam Honey bees Bumble bees Solitary bees Lowest Lethal concentrations Acute exposure Chronic exposure < 250 ppb No data No data 120 ppb No data No data Lowest Sublethal Concentrations Acute exposure Chronic exposure No data 50 ppb No data 100 ppb No data No data
Toxicity of neonicotinoids against honey bees. Toxicity to honey bees Neonicotinoid Degree of Toxicity Contact LD 50 Oral LD 50 A cetamiprid Moderately toxic 7.1 Ug/bee 2-8.9 Ug/bee 3 8.85-14.52 Ug/bee 3 Clothiandin Highly toxic 0.022 Ug/bee 2-0.044 Ug/bee 4 0.00379 Ug/bee 5 Dinotefuran Highly toxic 0.024 Ug/bee 2-0.061 Ug/bee 6 0.0076-0.023 Ug/bee 6 Imidacloprid Highly toxic 0.0179 Ug/bee 4-0.024 3 Ug/bee 7 0.0037/Ug/bee 7-0.081 Ug/bee 6 Thiacloprid Moderately toxic 14.6 Ug/bee 2 38.83 Ug/bee 9 8.51-17.3Ug/bee 6 Thiamethoxam Highly toxic 0.024 Ug/bee 10 0.029 Ug/bee 2 0.005 Ug/bee 10 Highly toxic : LD 50 < 2 Ug /bee Moderately toxic : LD 50 2 10.99 Ug /bee Slightly toxic : LD 50 11 100 Ug /bee Practicly toxic : LD 50 < 100 Ug /bee
Effect of Neonicotinoids on wild life * In March 2013, The American Bird Conservancy published 200 studies on neonicotonids calling for aꞌ ban use as seed treatment due to their toxicity on birds, aquatic invertebrates and other wild life * A 2013 Dutch study found that water containing allowable concentrations of imidacloprid had 50% fewer invertebrate species compared with uncontaminated water.
In July 2014 issue of the Journal Nature, a study based on observed correlation between declines in some bird populations and the use of neonicotonoids in the Netherlands demonstrated that the level of neonicotinoids detected in environmental samples correlated strongly with the decline in some bird populations of insecteating birds.
Toxicity of neonicotonids on mammals (mg/kg. body weight) Neonicotinoids Acetamiprid Clothiandin Dinotefuran Imidacloprid Thiamethoxam Rat oral LD 50 450 > 5000 2000 4870 > 5000 Rabbit dermal LD 50 > 2000 > 2000 > 2000 > 2000 > 2000
Toxicity of neonicotonids on cartain organisms Neonicotinoids Bird oral LD 50 Fish LC 50 Bee LC 50 Acetamiprid PNT PNT MT Clothiandin PNT PNT MT Dinotefuran PNT-MT PNT MT Imidacloprid MT MT MT Thiamethoxam ST PNT MT PNT = Practically non toxic ST = Slightly toxic MT = Moderately toxic
Recommendations * The bee safety of currently approved uses of neonicotinoids should be reassessed and all conditional registration re examined and/or suspended until we understand how to manage the risk of bees.
* Before registration for a specific crop, research facilities should investigate the influence of application method, target plant species and environmental conditions on levels of neonicotonids residues in pollen and nectar.
* All neonicotinoid products used by commercial and agricultural application should include a clearly stated and consistent (Standardized) warning on the label about the hazard to bees and other pollinators
* Products marketed to home owners for use on garden, lawn, or ornamental plants should all have a clear warning label that prominently states a use of this product may result in pollen and nectar that is toxic to pollinators. * Legislators, regulators should consider banning the use of neonicotinods for cosmetic purposes on ornamental and land scope plants
III The Real Situation of Neonicotinods Restriction
Restriction on Use * Until we know it is safe for bees, the use of neonicotinoids on crops such as apples that bloom for a specific period of time each year should not be allowed during or before bloom. such application likely increase residue levels in pollen and nectar and increases exposure and risk to bees.
* For crops that bloom continuously or over a long period of time (Squash or tomato), IPM Professionals should develop clear methods for how neoicotinoids can be used, so that concentrations of these products in crop pollen and nectar stay below sub lethal levels.
* Until a ban on cosmetic use of inseiticides goes into effect, all neonictinoids marketed for non agricultural use should have label restrictions that limit application times, and reduced application rates on plants visited bees.
Politics meets Science: The case of neonicotinoids in Europe 1. In April 2013 based by the European Food Safety Authority (EFSA), the European Commission announced a two-year ban on the use of three neonicotinoids on certain flowering crops. 2. The three neonicotinoids are: Clothiandin Imidacbprid and Thiamethoxam.
3. Although there was a strong lobbying against the proposed ban by multinational chemical companies that produce the insecticides along with farmer s groups, strong lobbying in support of the ban came from environmental groups, beekeeping organizations and the general public.
4. Even after two rounds of voting, the European parliament did not reach a consensus, forcing the European commission to exercise its rights and impose the ban based on the evidence presented in scientific data of the European Union. 5. On 29 April 2013, 15 of the 27 EU member states voted to restrict the use of three neonicotinoids for two years starting 1 December 2013. Eight nations voted against the ban while four abstained.
6. The restriction on the use of neonicotinoids remain in place depends on the outcome of research of risk evaluation by the end of January 2017. 7. The law restricts the use of imidacloprid, Clothiandin and Thiamethoxam for seed treatment, soil application (granules) and foliar treatment in crops attractive to bees.
8. Some restrictions are already in place for neonicotinoids as France, Germany and Slovenia. 9. The UK which voted against the bill, disagreed: Having a healthy bee population is a top priority for us but we did not support the proposal for a ban because our scientific evidence doesn t support it.
Health Effects on Birds, Aquatic Invertebrate and other Wild Life In March 2007, the American Bird conservancy published a review of 200 studies on neonicotinoids calling for a ban use as seed treatments because their toxicity to birds, invertebrater and other wild life.
Health Effect on Humans A study on rats suggests that neonicotinoids may adversely affect developing brain. human health especially the
Thank You