• Español
  • Français
  • English
  • Português

FAQ on neonicotinoids: harmful insecticides for bees.


FAQ on neonicotinoids: harmful insecticides for bees.

Discussion from June to July 2013.

Good morning everyone. My name is Carolina Cardoso. I am working at the European Beekeeping Coordination (EBC): http://www.bee-life.eu/ as communication coordinator. The EBC is a technical group formed by professionals of the beekeeping sector from different countries of the European Union. It gathers beekeeper associations in Europe and its aim is to study the impact on bees' health of environmental threats such as pesticides and to provide expertise on various dossiers regarding the provision of an optimal environment for bees and pollinators.Following the partial ban in the European Union on the use of 3 neonicotinoid pesticides, the EBC has been asked by the TECA team to provide information on the neonicotinoid pesticides and to moderate a discussion on the topic. The aim is to better understand the situation and what it means for beekeepers around the world. Barbara Herren, Coordinator of the international initiative on pollinators at FAO and myself will be trying to do so.

Purpose of the discussion

Neonicotinoids insecticides have been recently in the frontline of many discussions. However, beekeepers have been highlighting the risks of these pesticides for more than 10 years, and only now their claims start to be officially acknowledged at EU level. After a review of three neonicotinoids - clothianidin, thiamethoxam and imidacloprid - Europe’s food safety watchdog (EFSA) confirmed that these three substances pose a high risk to bees. On 29 April 2013 the EU Commission and a majority of Member States voted for a partial ban of these molecules for a two-year period starting from 1 December 2013 onwards. The restriction was adopted and published in the EU Official Journal on 24 May 2013 (1) (2).

In this discussion, we would like to share with you the background of the ban and key elements that made the ban a reality in Europe. We would also like to explain to you the effects of neonicotinoids on bees and the environment, and present possible farming practices without the use of neonicotinoids. We will also look at how pesticides are evaluated and placed on the market in the EU specifically and propose and discuss about sustainable and pollinator friendly farming alternatives.

In this discussion, we will tackle the following questions.

We will elaborate the questions one by one and after each question, leave some time for you to comment.  Feel free to add any questions and comments on the forum: your testimonies are all welcome about the decline of bees vitality, experience of working without neonicotinoids, scientific experiments, practical experiences, citizen actions, positive collaboration with farmers and beekeepers, etc.

1.    What are neonicotinoids? On which crops are they used? What are some of the commercial names of pesticides available on the market that contain neonicotinoids? Why are they dangerous for bees?

2.    Why are neonicotinoids a threat to ecological health? What do they do to bees?

3.    Which main steps contributed to the partial ban decided on 29 April 2013?

4.    What does the ban mean and when will it enter into force and until when?  Does it mean that nobody in Europe can use pesticides containing the 3 banned active substances?  

5.    How will farmers be able to protect their crops now from harmful pest ?  Will the ban lead to reduced yields and food availability in Europe ?

6.    Role of European Citizens and NGOs in getting the ban approved (petitions, letters written by citizens to Ministers, etc.).

7.    What alternatives are available for farmers?  

8.    Are these pesticides only used in Europe or also in other parts of the world? Do they also harm bees in those parts of the world ?

9.    How to ensure a better future and decrease the use of bee harming pesticides in our environment?

10.  Other related links

11.  …

This discussion will be facilitated and supported for a month (from 29 May to 1 July 2013). At the end of this period, we will summarize the key points shared and discussed in a summary note.


 1. What are neonicotinoids? For which crops are they used? What are some of the commercial names of pesticides available on the market that contain neonicotinoids? Why are they dangerous for bees?

Dear all, here is some first info to launch the discussion!

Neonicotinoids are nerve-agent insecticides. That means that they affect insects nervous system.  Their name comes from nicotine, a substance with insecticide properties to which they are chemically related. Neonicotinoids are largely used worldwide in agriculture, fruit production, livestock treatments, gardening, forest management, etc. Eight neonicotinoid molecules exist so far in the world. In Europe 5 molecules of this family are authorised on the market: imidacloprid, thiamethoxam, clothianidin, thiacloprid and acetamiprid. These active substances are used in several pesticides such as Gaucho, Confidor (imidacloprid), Cruiser, Actara (thiametoxam), Poncho (clothianidin). A new neonicotinoid is currently passing through the authorization process in the EU: sulfoxaflor.

They are used to fight against pest such as Aphids, vector of diseases such as Barley yellow dwarf virus (BYDV). Other pests are Blackcutworms, Wireworms, Corn rootworm, European corn borer on corn, Flea-beetles that poses problems to oilseed rape, etc.

Neonicotinoids can be applied as seed dressing, soil drench, injection, granules or foliar spray.

They have the particular characteristic of being systemic pesticides. That means that they are relatively high soluble in water, so once applied they are absorbed by the plant. The chemicals circulate then through the plant’s tissues, killing the insects that feed on them. Compared to contact pesticides, this innovation was presented as an environmental friendly application of pesticides. However the huge quantity of neonicotinoids in use, their huge persistence and ubiquitous presence in the environment (water, soil, air, nectar, pollen…) do not avoid the exposure of bees and the whole ecosystem to these products. 


Feel free to add your comments and questions on that point. Then on Monday or Tuesday, we'll come to the 2nd question. 

Gianluca Pressi's picture

Hi to everybody.

I am an Italian veterinarian, with a building experience on honey bees and bees, also focused on sustainable beekeeping in developing countries. I would just like to raise a witness on the situation in my area (Northern Italy).

Even if the regional and national regulation is (almost) clear on protecting honey bees, avoiding pesticides treatments during plants flowering and recommending to cut the baseground flowers before any treatments, the situation of honey bees poisoning is not yet solved.

After the huge amount of acute episodes of dead bees, about four years ago, the situation has improved thanks to the suspensions of utilization of neonicotinoids for seeds dressing. In any case the bees (not only honey bees) are still under a continuos danger being exposed to the utilization of pesticides for other kind of treatments (i.e. fruits spraying) and because of the uncorrect and illegal utilization of products.

There are different reportings of sub acute poisoning which is very difficult to be seen by beekeepers because the hives might be still full of bees but mainly young ones while the foraging ones are dying far from the hive, uncapable to get the way back home. In Italy  a surveillance system for bees poisoning (Spia under Beenet project) is active  and it tries to follow all the reportings about these episodes. This requires a partiular attention by the beekeepers and prompt advise, also because the laboratory tests are complicated and has to be done on an high number of bees recently dead or dying and immediately frozen.

All the persons involved in beekeeping sector try to sensitize the community and to open a way of discussion with farmers that, in most cases, do not know the importance of bees for their own work and for the environment (finally human health also).

I was directly involved in one of these episodes and we have collected also some short movies on the abnormal behaviour of bees which can be seen on the following link:


(I apologize for the lack of English translation at the moment)

The lab test are ongoing but the "clinical" examination is quite clear...and during the same period of poisoning a farmer was seen to treat flowering prunes without cutting flowers on the ground with an unknown product but it is difficult to demonstrate a connection between the two episodes. In my area there are also cultivation of maize, rape, peaches, kiwi and other minor ones.

Hoping to have been on the subject.

Best regards 




Dear Gianluca,

Thank you very much for this testimony and short movies on abnormal behaviour of bees.

Risk management measures, such as avoiding insecticide application when flowering, cutting baseground flowers, or even the recent partial ban; are welcome but not enough. I fully agree with you. These measures aim to decrease the risk by decreasing the uses of pesticides for a certain period, but do not mean bees poisoning problem is solved, because of all the aspect you mentioned: many applications are still in use, risk management measures are not always properly applied, and in the end bees are still exposed – above all when dealing with neonicotinoids which persist for a long time in the environment.

The best pesticide risk management measure is no use of harmful pesticides to bees (impede to put them on the market, and withdraw them fully when risks AND lack of information are indentified – this point will be discuss in the further questions). And above all, try to use pesticide as the last solution, and prioritize good farming practices. 

Independent bees poisoning monitoring, such as bee-net is an essential tool to assess bee health and impact of risk management measures. Italy and Austria have created officially such network at the moment. Bee-net: http://www.bulletinofinsectology.org/pdfarticles/vol66-2013-160-160beenet.pdf  MELISSA: http://www.ages.at/ages/landwirtschaftliche-sachgebiete/bienen/forschung/melissa-bienen-mais-raps/projektinformation-melissa/ See also: http://bee-life.eu/en/doc/199/

To ensure risk management is correctly applied at national and regional level, communication between beekeepers and farmers is also a key point. Do you have any specific example on how it is done in your region?


From 1 December 2013 (when the partial ban will start), are Bee-net going to monitor bees poisoning and exposure to neonic around maize, rape, plum, peach, kiwi field and other crops in your Northern Italy? Are farmers and beekeepers going to participate?

Best regards, 


Dear Carolina,

Thank you for this interesting information.

You mention that the systemic pesticides were originally considered as “environmental friendly pesticides” because they would only affect the insects that attack the plant to which they are applied compared to contact insecticides which affect all insects ? Could you elaborate further ?

So, if I understand correctly, the systemic pesticides are dangerous for the bees because they also end up in the nectar and the pollen of the plants that were treated with these pesticides ?





Dear Charlotte, thank you for this question. 

Contact pesticides don’t enter into the plant. They stay at superficial level. Insects are exposed by contact and ingestion. Applications: sprayed. 

Systemic pesticides are absorbed by the plant and distribute within the plant. This protects the plant “from inside” from all the insects that may feed from the plant parts. Insects are exposed by contact and ingestion.  Application: sprayed, seed coating, granules, injection in stem, ferti-irrigation.

Both contact and systemic pesticides can be spread in the environment and the food chain, leading to collateral effects on the biodiversity and untargeted species. 

Seed coating, for example, is a type of application that is considered environmentally friendly by the pesticide companies and seed producers because it is a targeted application. However, seed coating, above all coating with neonicotinoids doesn’t impede pesticides to spread in the environment:- Dust drift is produced at sowing (leads to air contamination)- Food sources for insects (nectar, pollen, honeydew, guttation water) are contaminated- Leaching (leads to water contamination)- Persistence in soil and succeeding crops.

Not only neonicotinoids can spread in all the environmental compartments, but they stay there for months at doses affecting pollinators.Very important: even if they are less spread and that doses are lower, these doses have sublethal and lethal effects on pollinators. (This will be discussed in question 2.)

Last but not least, seed coating is a prophylactic treatment i.e. a preventive treatment to avoid pests in the case there might be any. In the EU market, most of the seeds are coated with neonicotinoids. They are sold even before knowing if pest will be present during the crop development.

On the following EFSA report, you will find details on neonicotinoids use in the EU (see page 10 to 12) :  Statement on the findings in recent studies investigating sub-lethal effects in bees of some neonicotinoids in consideration of the uses currently authorised in Europe.

Dear Carolina,

thank you for the additional explanations !




Gianluca Pressi's picture

Dear Carolina,

since the neonicotinoids are relatively high soluble in water why we do not find them in the honey but only in the wax (and on the bees for a short period of time)? ...which means that are also lipophilic?

thank you



Dear Gianluca, 

This is a good question.

Indeed, neonicotinoids are rather highly water soluble pesticides, and not that much soluble in fat. However, it doesn’t impede neonicotinoids to be distributed in fat matrices, such as wax.

There has not been a lot of research done on why neonics are more present in wax than in honey. However, here are some possible answers:

  • Potential exposure of forager bees to contaminated nectar is not yet well understood. However, if forager bees consume some of the nectar they are carrying during their forraging flight and that nectar is contaminated with neonic doses leading to lethal or sublethal effects, the forager bee dies directly or may not come back to the hive (see below in question 2, on chronic and sub-lethal effects of neonics on bees). Therefore, few contaminated nectar is brought back to the hive. As a result, it could happen that the sensibility of analyses is not good enough to detect concentrations in the order of picogrames/gram. It must be said that the quantities found in honey could pose a risk for beehives, but not as much to humans consuming this honey.


  • Pollen (contains +/- 30% of fatty acid, i.e. a fat) and resin are not ingested by bees when foraging. They are stored in the pollen baskets on the hind legs of the bees. So neonics present in the pollen or resin don’t affect the foraging bee immediately. Contaminated pollen/resins arrive thus more easily in the hive. Afterwards, neonic can be disseminated in beebread, propolis and wax, along the fatty matrices of the hive.


  • Wax stays in the hive for a longer period, and generally stabilize molecules.  As a result it somehow provides a "history" of the residues that the colony has been in contact with.


  • The presence/absence of residues may depend on the technique of extraction of the different matrices. In the case the matrix is obtained from a piece of frame that was cut containing honey, beebread, propolis and obviously wax, it could eventually happen that the matrices used for analyses are not 100% what we want to analyse. 

 Hope this helps.  If you have more questions, feel free to post them !  




Dear all, here is already some more content. You can always add comments on previous questions, no problem. 

Why are neonicotinoids a threat to ecological health? What do they do to bees?

Neonicotinoids persist in the environment for years: the half-life of clothianidin in some soils has been measured at 148 to 6900 days. Imidacloprid remains in the soil as well, it can be absorbed into untreated follow-on crops, up to two years after first use, and can then emerge in pollen and nectar of untreated flowers at levels toxic for bees. Honeybees are exposed to neonicotinoids pesticides in the environment and in the hive, where they stock contaminated feed. 

You can read more about why neonicotinoids are a threat to the environment on the EBC and Slow Food factsheet: Why are neonicotinoids a threat to ecological health and safety of the European Union?  French version: here. Czech version: here.

Neonicotinoid insecticides are extremely high toxic compounds for bees, having an acute toxicity of more than 7.000 times higher than DDT. This means that one sole contact with only 4 ng per bee could kill it. I would like to remind you that 1 ng is 0,000 000 001 g. So extremely low doses of these compounds can be lethal for bees.

Chronic and sub-lethal effects on bees: even smaller doses than dose mentioned above, are able to affect pollinators. Behavioral and physiological effects have been observed such as disorientation and inability to navigate back to the hive, reduced foraging efficiency, impaired memory and learning, failure to communicate within the colony, collapse of brood-rearing, decrease of metabolic efficiency and weakening of the bees immune system. Following an exposure in the long run, for example by consuming contaminated pollen, nectar or water, these products have shown to be lethal at doses even lower than dose triggering acute mortality. Studies show doses up to 100.000 times more toxic when bees fed over ten days on contaminated food. 

Metabolites: some of the metabolites, the compounds in which these molecules are degraded, can as well be highly toxic both in acute (after one contact) and chronic terms.

Synergistic and cumulative effects: one important point to understand and to take into account is that when combined with other pesticides, often fungicides, but also other insecticides and acaricides, the toxic effects of neonicotinoids on bees increase dramatically. Furthermore, a synergy exist between these products and a wide range of pathologies: bacterial, viral and fungal diseases.

Greenpeace’s report ‘Bees in decline’ published in April 2013 studies seven bee-harming pesticides, of which neonicotinoids. For a summary see the table on page 8-9.