Pheromones fall foul of EU Pesticide Directives  

Even though the European Union is revoking 320 active ingredients from the pesticides market starting in July this year, alternative methods of pest control face many obstacles before they can become readily available and affordable to farmers. John Chandler reports on the difficulties of getting pheromone products registered in the EU.

More than 60% of the agricultural pesticides on the EU market in 1993 could be withdrawn from use in the next two years, under the European Commission’s re-evaluation of its active ingredients approval system [PN57 p8]. In its recent communication Towards a Thematic Strategy on the Sustainable Use of Pesticides, the Commission outlines possibilities for substituting the most harmful pesticides with safer alternatives, including non-chemical methods, and encouraging low-input or pesticide-free farming(1). The current registration system in the EU and member states for pest control products puts serious obstacles in the path of approving biological pesticides [see PN 57 p18 and PN58 p17] yet there are no concrete proposals from the EC for facilitating the approval of non-pesticide control products which are inherently less hazardous than most chemicals. Many in the alternative pest control industry fear that environmentally positive solutions will never make it onto the market unless these conditions change.
    In agriculture and horticulture, the pesticide authorisation Directive 91/414/EEC severely limits the availability of the range of natural techniques that organic and integrated pest management farmers desperately need, by classifying the data requirements for approval as being the same as those for synthetic pesticides. Under this Directive, insect pheromones are classified as semio-chemicals or ‘biologicals’. What this means in practice is that if a pheromone product is to be promoted and marketed as a pest control system, the pheromone has to be registered by the regulatory authorities as if it were the equivalent of a synthetic pesticide. This is a long, tortuous and expensive procedure, beginning with the need (as for synthetic pesticides) to register the active ingredient at EU level, which involves the generation of a full toxicology package, a review dossier and payment of substantial EU review fees, to a total cost in the region of £300,000. Prior to commercialisation, the product would next require registration on a by pest/by-crop basis in each member state, which requires the submission of an additional toxicity package on the formulation, a full additional review dossier, at least six Good Laboratory Practice efficacy studies (over two years) and in the case of the UK, an additional £64,000 review fee. The Biocides Directive (for amenity and public health insect pest control) extends these requirements to products for use in non-agricultural applications.

Regulatory support for pheromones in North America
The US has long pioneered research and utilization of various insect pheromone pest management techniques. In contrast to the EU, the US has adopted a more pragmatic approach to pheromone registration and use within the guidelines for reduction of pesticide use developed by the Organisation for Economic Co-operation and Development (OECD). For US registration, no field trial data is required by the Environmental Protection Agency (EPA), although field demonstrations and approval from government bodies is important – ensuring recommendations for using the technique. Experimental use permits are granted by waiver if the pheromone is already known and has been used before (even if only in pest monitoring systems). There are special waivers applied to most data submission requirements, an accepted read – across for toxicological and residue issues based on published data and an appetite from the EPA to provide fast-track, much reduced approval requirements, time scales and costs, in the order of 6-9 months and around US$40,000-50,000 (£27-34,000).
    Canada’s regulator, Environment Canada, has recently adopted a similar approach, indicating it will follow the new OECD guidelines for registration of pheromones and other semio-chemicals, reducing fees for registration and accelerating the process in an attempt to provide alternatives to pesticides – although at present field trial data is still required for regulatory approval.
    In the EU, the potential markets for pheromone trapping and mating disruption techniques do not justify the huge expenditure required for registration purposes, as many of the target insects pests amenable to these techniques are found in relatively minor crops. It is, however, possible to market pheromone systems as ‘monitoring’ techniques. Monitoring traps are exempt from the need for registration because they do not carry the claim that they ‘control’ populations. This approach is being followed by most of the major players in the ‘biologicals’ market in Europe (e.g. Agrisense, Koppaert, Agralan). This, however, makes product development more difficult and increases marketing costs. End-users need to be advised to look for control success but this is not permitted in the form of conventional pest control advertising and promotion.

Improved pheromone techniques developed
Current pheromone techniques use female insect sex attractant chemicals, which are highly species-specific, to lure or confuse males. Pheromone traps can be used to monitor the pest population levels, for better pest management decision-making, or to disrupt mating and reduce subsequent egg-laying. However, adoption of currently available mating disruption systems in Europe has been disappointing, mainly due to the high costs. For codling moth control in apple orchards, Italian systems require between 800-1,000 pheromone release stations per hectare, while the UK has no registered codling moth pheromone systems to date, as the small and medium-scale companies involved are hampered by the registration costs and end-user prices would be uncompetitive with pesticides. 
    The ExoSect company has developed an improved pheromone delivery system called the ExoSex ‘Auto-Confusion™’ technique. In ‘auto-confusion’ the male moths are attracted to a dispenser where a pheromone-impregnated powder electrostatically contaminates them, using the insects themselves as flying dispensers (mobile point sources) of pheromone dissemination. The contaminated males serve to enhance the confusion effect, thus reducing or preventing successful mating and reproduction. In addition to the beneficial features of other pheromone technologies (reduction of pesticide sprays, toxin-free, pest-specific, benign to parasites and predators and fully compatible with IPM programmes), ‘auto-confusion’ has the advantages that: fewer stations (point sources) are required; the stations are easy to set up; and lower pheromone dosages are used; thus leading to reduced labour and overall pest management costs. For codling moth, only 25 stations per hectare are needed and the system uses 1,000 times less pheromone than current commercially available systems, disseminating levels lower than or equal to quantities released by codling moth populations.
    ‘Auto-confusion’ is most efficient when applied to monocultures or extensive areas of the target to be protected. It will not work well in small areas surrounded by other crops (e.g. individual trees in an orchard, or a small vegetable patch) where fresh immigration of the target pest is possible. Similarly if a treated insect has the ability to emigrate from a treated area there will be a lower level of treated insects to create auto-confusion. To optimise efficacy, dispensers should be put into the field before the first generation of insects emerge. Correct timing can ensure minimal successful mating and much lowered subsequent pest populations
    The technique is not a magic bullet for pest control since most monocultures have an overlapping pest complex, which requires that ‘auto-confusion’ needs to be part of a carefully planned Integrated Crop Management (ICM) programme. The new technique will also need extensive promotion and farmer education to ensure its correct utilisation. There are, however, major opportunities to replace or eliminate many of the blanket spray rounds used in traditional control programmes – at costs equal to or lower than pesticide spraying. 

Creating a supportive regulatory environment 
To approve ExoSex ‘auto-confusion’ techniques in the US will be much cheaper and quicker than in Europe. The ExoSex substrate carrying the pheromone is a food grade substance already approved by the US EPA and cross-referencing of registered data for pheromones already in practical use is permitted. Currently EPA indicate that the ‘auto-confusion’ technique would attract special consideration by virtue of its even lower pheromone dosages than existing pheromone systems and that registration would likely be granted in 6-9 months and cost in the region of US $60,000 (£40,000) per product per pest. In the EU, excessive regulations and costs serve to squeeze out innovative products for small markets, like ‘auto-confusion’, in favour of less target-specific agrochemicals being mass-produced for the larger markets.
    Both organic farmers (who have very few approved insect pest control alternatives) and ordinary farmers who are interested in reducing the pesticide burden to the environment are therefore being denied access to exciting, new environmentally positive technology. In the EU, potential target pests in the organic sector include turnip moth, pea moth and a variety of cutworms – but these are small niche markets and from the purely business point of view there is little sense in spending hundreds of thousand of pounds obtaining regulatory approvals for pests and crops when it would take ten or more years of sales just to recoup the regulatory costs.
    The pest management industry is actively lobbying for more pragmatism in respect of semio-chemical use under EU legislation and is receiving considerable sympathy from certain quarters, but changing the regulations is a medium to long term process. The UK’s Pesticides Safety Directorate recently indicated their willingness to discuss issues in registration of non-chemical alternatives. ExoSect welcomes this possibility of a more pragmatic approach and is now in dialogue with PSD on options for consideration, which might involve much lower submission fees and data read-across, encompassing both published scientific evidence and reference to the OECD guidelines for toxicity classification. 
    ExoSect will also target organic farmers groups and others interested in pesticide use reduction to assist in this process. We are applying for a government-sponsored DEFRA agricultural research programme to further promote pheromone use for insect pest control in agriculture at extremely low dosage rates. We anticipate that ExoSex ‘auto-confusion’ solutions if placed with ‘key influencer’ organic farmers, will quickly achieve a reputation, which will overcome any marketing difficulties.
    Any opportunities to reduce the pesticide burden to the environment and to encourage sustainable/organic crop husbandry require special thought and attention – not the approach that ‘if it’s not in the rules, you must still follow the rules’. The message needs to be that EU regulations towards the use of ‘biologicals’ in general, and insect pheromones in particular, require a complete rethink. 

References
1. Towards a Thematic Strategy on the Sustainable Use of Pesticides, COM (2002) 349 final, European Commission, July 2002 http://www.europa.eu.int/comm/environment/ppps/home.htm
2. Guidelines for registration requirements for pheromones and other semiochemicals used for arthropod pest control. OECD Series on pesticides no.12, ENV/JM/MONO (2001)12, OECD Environment Directorate, Paris, 26 Feb.2002. http://www.olis.oecd.org/olis/2001doc.nsf/LinkTo/env-jm-mono(2001)12

John Chandler is Managing Director of ExoSect Limited, 2 Venture Road, Chilworth Science Park, Southampton SO16 7NP, UK, info@exosectuk.com, www.exosectuk.com    

[This article first appeared in Pesticides News No. 59, March 2003, pages 10-11]