March 2019 - NeemCo receives funding for research to tackle weevil menace

NeemCo is one of five companies to have each been awarded up to £30 000 research funding to develop new techniques for managing the large pine weevil (Hylobius abietis) - the most serious pest of newly planted young trees in Scotland.

The companies - applicants to an open innovation competition from Forest Enterprise Scotland and launched by Rural Economy Secretary Fergus Ewing last year – will look to develop alternatives to current chemical pesticides.

The pine weevil is estimated to cause direct losses of around £5million to forestry across the UK every year as well as causing significant delays to the re-establishment of future forest crops.

Welcoming the announcement of the research grant awards Mr Ewing said:

“Developing innovative and successful solutions to tackle this serious pest of young trees is imperative for the health public and private woodlands across Scotland – and indeed across the UK.

“It is very heartening to note that technology companies from Scotland are well represented amongst the contract winners, and that all the research projects will bring economic benefits to Scottish forestry businesses.

“The forestry sector will be following progress with a keen interest and I wish all of the research projects well in their endeavours.”

NeemCo’s project, partnering with the University of West of Scotland’s Departments of Biology and Chemistry, uses a push-pull approach to pest control, using only naturally-derived compounds. A plant protection product derived from the seeds of the Indian neem tree will be applied to young forest trees to discourage weevil feeding, whilst simultaneously an attractant lure encourages weevils to feed on a toxic bait before they feed on any young trees.

The funding is one of the Scotland Can Do Innovation Challenge Fund challenges and will provide total funding to businesses and organizations of up to £550 000. The £9.2m fund is designed to increase the level of business innovation in Scotland by encouraging businesses and organisations to collaborate with Scotland’s public sector to develop innovative solutions to societal challenges.

Administered by Scottish Enterprise, the fund is a joint project between Scottish Government, Scottish Enterprise, Highlands and Islands Enterprise and Scottish Funding Council. Forest Enterprise Scotland is leading the project for the UK, with additional delivery support from ConFor and Forest Enterprise England.

Successful bidders retain intellectual property rights to their ideas so that they can be seamlessly brought to market after the end of the research and development phase.

The companies now have five months to develop and prove their ideas, in a bid to win further funding of up to £200 000 for prototype testing of one or two of the proposed new control options. Testing will take place in the field and over the tree planting seasons 2019-2020 and 2020-2021.


The progress of climate change, increased international transport of grown plants, and the desire to use less toxic pesticides, are combining to create an increasingly problematic situation in large-scale forestry, usually of conifers, as well as in public-amenity parkland with mature specimen trees.

It is unlikely that Riddance®, a natural product, will ever be used on a large scale in forestry. It has a short half-life when sprayed onto plants or trees.

It has, however, two advantages compared to many other pesticides: it has no toxicity towards higher animals including, of course, people, and it acts systemically. It can penetrate leaf lamellae and perhaps more importantly, can be taken up from soil via the roots. It has also been injected successfully into the trunks of mature trees in both Europe and North America, where experiments have shown that this method can control pests such as sawfly.

In the south of UK, a recently-appearing novel threat to both tree and people, is the oak processionally moth, whose larvae can strip the foliage from an oak tree, and which produce a mass of hairs which can cause irritation and allergic reactions in anyone who comes in contact with them. Experiments carried out in Germany have shown that the German version of Riddance®, called NeemAzal™, is very effective against this moth. Unfortunately, the extract is not yet registered in the UK.

Azadirachtin is the only alternative to conventional insecticides currently available for managing most sawfly pests and white pine weevil. This bioinsecticide is safe to mammals and birds. It does not pose a significant risk to most other non-target organisms including bees, fish and aquatic insects at effective dosages, and it degrades readily in the environment.

The short residual life of azadirachtin-based insecticides when applied as a foliar application, although attractive from an environmental perspective, can be a significant limitation for forest management. This limitation may be overcome by applying neem formulations that can persist for a year or more, systemically into trees. For example, systemic applications into large pines for pine false webworm control is a promising approach for selective treatments, including seed orchards, small pockets of infestation, and ornamental trees in urban environments.

The cost of neem insecticide formulations is higher than most conventional insecticides, but their low impact to non-target organisms makes them an attractive alternative. This is even more so with systemic applications, which further reduce any impacts to non-targets, or hazards to handlers.

Source: International Pest Control


Pine weevil (Hylobius abietis)

The large pine weevil (Hylobius abietis) is an important pest of coniferous seedlings throughout Northern Europe, including, of course, the pine and spruce forests of the UK. It attacks seedlings in the replanting of harvested woodland, and frequently kills all the trees. Currently control depends on the pyrethroid α-cypermethrin, but this pesticide will be phased out by 2017. Forestry Research is testing alternative plant protection possibilities. One of these is the use of extracts of the kernels of the neem tree, already widely used throughout the world as biological plant protection products.

The weevil eats the bark of newly replanted seedlings, and depending on the extent of the damage, may kill the young trees. Currently control depends on the pyrethroid α-cypermethrin, but this neurotoxic insecticide has already had a stay of execution, but will be phased out if suitable alternatives become available. Neem extracts have been shown to protect against the weevil in field situations, but for limited periods of time. It is hoped that further experimentation with Riddance® applied systemically will give longer protection.

Topically applied neem extracts can protect seedlings against the weevil.  Extracts have been shown to act systemically, and to be taken up via the roots. The aim is to develop a formulation of a biological pesticide, which is cost effective and acceptable to the Forestry Commission, and which will reduce losses in commercial forestry, a vitally important resource in Scotland.


Resistance to Riddance®

Resistance is a significant issue with neuro-toxin based pesticides, such as organophosphates, pyretheroids, and avermectins.
Neem extracts used as commercial biocides and plant protection products for almost 20 years in the USA and EU, and as yet, there have been no reports of signs of resistance in target organisms.

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