This is part of the book “Stéphane Foucart et les néonicotinoïdes. The World and disinformation 1“, where I present the reasoning developed by the journalist in the corpus. What is said in this chapter is my view on what the journalist writes. All quotes are translated (by me), except the ones marked between [ ] in the french version (french quotes are to numerous to be marked in this one).
“Regarding the decline of insects and bees, there is a great deal of evidence pointing to neonicotinoids as the major cause. They are among the most effective insecticides ever synthesized; they are used mostly preventively and systematically, as a coating for seeds, on millions of hectares of field crops; they have a chronic toxicity much higher than their acute toxicity; they have a very broad spectrum of action and target all insects; they are persistent in the environment; they are soluble in water and can thus be transported far beyond their place of application.” (55)
There is a scientific consensus on the deleterious effect of NNIs on wild pollinators, in particular because they are able to act at very low doses on the nervous system of insects in general and bees in particular. They can have neurotoxic effects endangering hives even at sublethal doses. (26) The danger they represent is such that 233 scientists published an opinion piece arguing that the use of NNIs must be drastically and urgently restricted. (46)
“Beyond the effect on bees, hundreds of studies published in recent years show, beyond reasonable doubt, that NNIs have negative effects on many types of organisms: arthropods, birds, organisms. aquatic, etc.” (65)
Barbara Pompili warned in 2016 that are piling up scientific studies showing the dangers of NNI to not only bees, but to our health and the environment in general. (66)
A review of the literature would estimate that their use thus weakens all “ecosystems by affecting soil invertebrates, the microfauna of rivers, amphibians, etc.” NNIs would also be one of the causes of the 50% decrease over 30 years of field bird populations in Europe. (26)
a. The introduction of NNIs
The decline of pollinators (9) (and of biodiversity in general) in the 1990s would have been concomitant with the introduction of a new class of pesticide: neonicotinoids. For Hallman et al. (2017), agricultural practices would be the only explanation for the 75% decline in insect biomass observed between 1989 and 2013. (35)
In 2016, the NNIs reportedly treated 6 of the 28 million hectares of arable land in France. (36)
b. Toxic substances
NNIs are very effective insecticides… too effective in fact. 60 g of imidacloprid per hectare on 423,000 hectares of beets, represents 25 tons of the product, which is enough to kill 3 million billion bees. (64) In 2003, the CST report in France recognized the dangerousness of imidacloprid on pollinators, which led to its ban. (4) Similarly, fipronil was banned after CSE concluded that its use “may appear to be ‘of concern’” and “does not exclude unacceptable risks”. (10)
EFSA published an opinion in January 2013 that the risks posed by three NNI pesticides (clothianidin, imidacloprid and thiamethoxam) represent “a high risk to bees”. This risk went through three routes of exposure:
- the emission of dust by the coatings during sowing;
- contamination by pollen and nectar;
- exposure by “guttation” (the exudation, by the plant, of water droplets). (4) (64)
In 2015, EFSA also judged that these 3 NNIs also represent these risks when used as a spray. (23) EFSA has also recognized a “high acute risk” posed to honey bees by dust from corn seed coated with fipronil. (10)
DiBartolomeis et al. (2019) quantified the “toxic load” of pesticides used by American agriculture between 1992 and 2014. It would have, over this period been multiplied by 48, almost exclusively because of NNI, which represent 92% of the toxic load over this period. (53)
Researchers led by Florian Millot and Elisabeth Bro observed the probable responsibility of imidacloprid in the death of 70% of 730 wild birds occurring between 1995 and 2014. This would mainly affect grain-eating insects, which would get poisoned by eating seeds coated with NNI. (42)
c. Sublethal toxicity
In addition to their lethality, NNIs are characterized by “sublethal” effects, that is, not causing death, but weakening the body.
“For example, exposure to certain pesticides can weaken the immunity of bees and promote the development of pathogens in the colony.” (33)
For example, Tsvektov et al. (2017) placed bees exposed to pollen contaminated with low doses of clothianidin in an untreated experimental hive. They observed that their life expectancy was reduced by 25% and that “their behavior differed from that of unexposed individuals, to the point of endangering the survival of the colony.” (33)
A study published on June 28, 2011 by PLOS ONE (Vidau et al. 2011) exposed bees to very low doses of thiacloprid or fipronil for ten days. They formed two groups: those being healthy and those previously infected with Nosema Ceranae, a very common parasite. They observed that 70% and 80% of bees infected with the parasite died, while those simply exposed to insecticides did not have “significant mortality”. It is the “cocktail effect” between the parasite and the pesticide that was lethal. (1)
Henry et al. (2012) observed that bees exposed to very low doses of cruiser (based on thiametoxam) developed a tendancy not to return to their hives. (3)
Bryden et al. (2013) tested the ability of a mathematical model to predict the evolution of colonies of bumblebees (Bombus terrestris). They fed the insects for 42 days with a sweet syrup containing (or not) 10ppb of imidacloprid, which would correspond “to the high range of the concentration reported in nectar and pollen”. At first there is no difference between the treated and control colonies, but after 3 weeks the treated colonies begin to decay. (12)
The study conducted by Penelope Whitehorn and published by Science in 2012 showed that “colonies exposed to very low doses of imidacloprid produced on average 85% fewer queens than others.” (14) m(17)
Hannah Feltham, Kirsty Parl and Dave Goulson (2014) studied 6 bumblebee colonies of initially identical size. For 2 weeks, the “colonies were fed in the laboratory with a sugar solution and pollen”, to which was added, for half of the colonies, respectively 7 and 6 ppm of imidacloprid [NdA: These doses would be “comparable to what pollinators encounter in nature, when the seeds have been transformed by the insecticide.” Note a small error from the reporter: it’s 0.7 for sugar water.]. Then the bumblebees were released into the wild and tracked down with an RFID chip. Treated bumblebees were also successful in foraging, but only returned pollen on 40% of their trips, compared to 63% for control bumblebees. Those who succeeded had, moreover, an hourly efficiency reduced by 31% compared to the control group. In total, the amount of pollen collected was 57% lower for the treated bumblebees. These effects were observed even one month after exposure to the product. (14)
A report published in 2015 by EASAC also observed that “very low levels of neonicotinoids have long-lasting sublethal effects on beneficial organisms”. (54)
d. Human toxicity
We would also observe sublethal effects… on humans! According to Mellissa Perry, a meta-study in which she participated (Cimino et al. 2017) reports “’associations with unfavorable developmental or neurological consequences’: increased risk of autism, memory impairment and tremors, a congenital malformation of the heart (called “tetralogy of Fallot”), as well as another serious congenital anomaly, anencephaly (partial or total absence of brain and skull at birth).” They insist, however, “that these suspicions are only indicative” and stress that their main message would be to draw attention to the lack of data on the subject. This would be all the more problematic as NNIs tend, as we shall see, to end up in waterways and imidacloprid is among the 15 most frequently detected substances in waterways. (28)
Delphine Batho also recalled, in a debate in 2017, that scientific studies have “established the impact of neonicotinoids on human health with” unfavorable neurological consequences on humans “”. (31)
e. The other possible causes: parasites, global warming…
There could be other causes of bee decline. We generally talk about the appearance of varroa (a parasite), beekeeping practices and global warming. Thus, according to a 2014 IUCN press release:
“Climate change, intensification of agriculture and changes in agricultural land use are the main threats these species face” (17)
Nonetheless Dave Goulson has “never seen clear evidence linking bumblebee and bee declines to climate change”. In addition, the absence of the term pesticide would “creak” and some would see “the influence of talks underway between the biodiversity protection organization and Syngenta, a major producer of agricultural insecticides.”” (17) While it is true that bad beekeeping practices certainly play a role in the situation, this role has conveniently been blamed by the agribusiness and agrochemical circles. (56)
Hallman et al. (2017) studied all the parameters that could explain the 75% decrease in insect biomass they observed. “The only parameter that the researchers were unable to control is the nature and evolution of crop protection techniques (ie pesticides) on the farms surrounding these protected areas.” (55)
The idea “that the general decline of insects is mainly due to climate change, natural pathogens, invasive species, etc.” Would also have been contradicted by the study published in 2019 showing the drastic increase in the “toxic load” of pesticides with the introduction of NNIs, which was multiplied by 48 between 1992 and 2014. Over this period, it would be composed 92% by NNI. (53)
No other cause would be able “to explain the homogeneity of the observed decline: warming is sometimes blamed, but it is favorable to certain insects in temperate zones (such as butterflies), but these are also declining. We blame bee diseases and bad beekeeping practices, but bumblebees and hoverflies are also declining, and even faster than bees…” (55)
f. Direct demonstrations
Several studies directly show, in vivo, the negative impact of NNIs on pollinators.
- Woodcock et al. (2017) studied the effect of three rapeseed plots, two of which were treated with clothianidin or thiamethoxam, on bees at eleven sites in three countries. The experience involved several tens of hectares. The health of several pollinators1 in these fields has been monitored for one to two years. Researchers observed a negative effect of NNIs: “Bumblebees produce fewer queens, and solitary bees produce fewer larvae when exposure to neonicotinoids is high.” (33)
- Three researchers from the University of Helsinki (Hokkanen et al. 2017) observed that rape, an oilseed close to rapeseed, had seen its yields decrease since 1993. In Finland, it was then harvested 1.7 tonnes per hectare compared to 1 , 2 today. The yield loss would have been most severe in areas where NNI use would be most intense. On the contrary, crops that are not very sensitive to the depletion of insects, such as barley and wheat, would not suffer from these drops in productivity. The authors conclude “only the adoption of neonicotinoid insecticides in seed treatment can explain the drop in yields in several [Finnish] provinces, and at the national level for the shuttle, through a disruption of pollination services by wild insects”. (30)
One can also see the responsibility of pesticides in general in the decline of pollinators behind the positive effect of organic farming. A study conducted by Vincent Bretagnole (Wintermantel et al. 2019) on the “Zone-Atelier Plaine & Val de Sèvre” shows a very positive effect of the proximity of organic plots on apiaries, their brood “increase by up to 37%, compared to beehives located at the heart of uniquely conventional farms.” This, even though the proportion of organic plots would be 5-15% at less than 1,500 m. (52)
g. Impact of non-honey plants
Pollinators can be exposed to NNIs by means other than pollination (pollen / nectar): guttation and dust from seedlings. (2) (4) (41) (55) The dangerousness of exposure by guttation has been shown by Girolami et al. (2009). The dangerousness of exposure by dust released during sowing has been shown by Greatti et al. (2003). (64)
In addition, NNIs would contaminate soils and thus subsequent crops, as well as wildflowers, and in addition, could “move” with the flow of water, as shown above. This issue would be all the more central as the main argument to support the reintroduction of NNIs decided in 2020 in France was that beets, being harvested before flowering, would not be visited by pollinators. S. Foucart makes fun of this argument by referring to the study by Yamamuro et al. (2019) (59):
“So during all this time, if the Shinji fishermen had complained to their minister about the practices of their neighboring rice farmers, they would no doubt have been told with confidence that their concerns were unfounded. It is well known: “Fish are not going to forage in the rice fields.”” (66)
Overall, Tsvektov et al. (2017) studied 11 apiaries in a maize growing area and observed that “colonies close to farms were more exposed to neonicotinoids than colonies far away”, even though maize is pollinated by wind and not by insects. “Much of the exposure is through wildflowers, contaminated by agricultural treatments.” (33)
h. NNIs and birds
Birds would be impacted by NNI in several ways:
- They can ingest seeds coated with NNI, which would lead to direct toxicity, as researchers at ONCFS have shown.
- They can ingest earthworms that have ingested NNIs.
- Their supply of insects would be diminished. This even affects granivores, which would be insectivores at the start of their life, as Christian Pacteau from Bird Protection League emphasizes. (43)
Hallman et al. (2014) would have shown that “the fall in populations of insectivorous birds was indeed linked to the concentration of neonicotinoid insecticides in the environment (in the Netherlands in this case)”, even at very low concentrations (20 ng / l surface water). (59) m(44)
A study concluding that low doses of pesticides would have little impact and would weigh “three to four times less in the decline of birds than the modification of their habitat”, would have done only a limited follow-up, between 2009 and 2011, and partial. On the contrary, several hundred studies show the deleterious effects on non-target invertebrates. (44)
Hallman et al. (2014) have shown that “the fall in populations of insectivorous birds was indeed linked to the concentration of neonicotinoid insecticides in the environment (in the Netherlands in this case)”, even at very low concentrations (20 ng / l surface water). (59) m(44)
A study concluding that low doses of pesticides would have little impact and would weigh “three to four times less in the decline of birds than the modification of their habitat”, would have done only a limited follow-up, between 2009 and 2011, and partial. On the contrary, several hundred studies show the deleterious effects on non-target invertebrates. As for the fact that the bird populations in the city have also fallen by a third, this drop may be related to other factors and does not demonstrate the absence of effect of pesticides on birds. It would therefore be credible that NNIs are at the origin of the decline observed in the CNRS and MNHN studies of 2018. (44)
A study published in Nature Stainability (Li, Miao and Khanna 20207 shows a strong link between the use of NNIs and the collapse of nesting birds. (65) Finally, birds could be affected by pesticides accumulated in the bodies of earthworms, a phenomenon highlighted by Pelosi et al. (2020). (69)
i. NNIs and fish
Masumi Yamamuro et al. (2019) observed that, in a Japanese lake, the wakasagi catches increased from 240 tonnes before 1993 to 22 tonnes in the following years. Those of eels fell from 42 tons to less than 11. The researchers followed the concentrations of imidacloprid over 20 years and the evolution of the abundance of small aquatic organisms. They observed that populations of aquatic arthropods collapsed the same year as the 1993 introduction of imidacloprid. This fall would have caused the fall of the eel and wakasabi populations, which feed on these organisms. This link would be validated by the fact that another species feeding not on invertebrates, but on microalgae, would not have been affected during the period studied. (59)
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