An EU-funded INBIOSOIL project has developed a new, eco-friendly method to control wireworm in potatoes that can be used in conventional and organic systems. The new method of pest control uses special formulated capsules called ATTRACAP®. They contain a strain of an entomopathogenic fungus that attacks specific pest insects and can reduce chemical pesticide use on potato farms.
The company BIOCARE is located in Lower Saxony, Germany. ‘We are overwhelmed by inquiries from farmers willing to use the product on their fields, therefore the upscaling of production will continue,’ Prof. Dr. Stefan Vidal, INBIOSOIL Project Coordinator, said. ‘We expect ATTRACAP to become a standard control strategy for both organic and conventional farmers,’ he added.
The capsules aim to control wireworms – currently regarded as the most pressing problem in potato production. ‘They contain compounds which are non-synthetic products and therefore their use is possible in both organic and conventional cropping systems. The Attract & Kill strategy, based on these capsules, will substitute the use of synthetic chemical insecticides,’ Vidal explained.
The launch of these capsules in 2016 in Germany came at a time, when virtually no specific synthetic compounds targeting wireworms were available. The compound used in conventional fields in the past was Fipronil, known commercially as Goldor® Bait, a product produced by BASF.
However, the European Commission introduced a moratorium on products suspected of playing a role in the bee disease Colony Collapse Disorder. Whilst national registration agencies say that emergency case approval of this product would be possible, BASF has not applied for it.
Economic costs of wireworm infestation
Conventional potato farmers are currently experiencing economic problems due to the poor quality of potatoes that have been damaged by wireworms. Meanwhile, organic farmers are also suffering severe income losses due the same pest.
‘Although reliable data calculating the economic impact of wireworms on crop yields is not available, farmer organisations in different European countries are willing to adopt this new pest control strategy simply because it works,’ Vidal outlined.
Moreover, the cost per hectare of ATTRACAP® capsules is such that even smallholder farmers can afford it and are happy to apply it on their fields, Vidal emphasised.
Biological nature of the killing agent
The killing agent contained in the capsules is an isolate of an entomopathogenic fungus, occurring naturally in arable soils worldwide. Given the 100 % biological background of this strategy, EU environmental protection goals are met. Moreover, the spores of the fungus are applied to the soil, restricting their unintended passive dispersal. This limits interactions with above-ground organisms such as honey bees. Furthermore, earthworms are not attracted to the capsules.
Control of other pests
According to Vidal, the INBIOSOIL project delivered even better results than originally anticipated. However, the project’s idea in the beginning was to additionally target other soil dwelling pests such as western corn rootworm (WCR) larvae, using the same attract-and-kill approach.
‘Laboratory and field experimental data did not provide sufficient control results, thus we are currently modifying the composition of the capsules to better control other pest species. Another pest, cabbage maggots (Delia radicum) is a new target for the ATTRACAP® capsules,’ Vidal said.
In the future, the basic technology developed by INBIOSOIL will be used to develop more environmentally-friendly pest control products. ‘Several proposals have been submitted to collect funding for these innovative developments,’ Vidal concluded.
Efficacy of the product in practice
Fabian Schaper, Head of Sales at BIOCARE in Germany told Global Potato News: “We are heading into our fourth season of selling the product in Germany in 2019, and we are doing trials in several countries of Europe and other parts of the world. The efficacy of the product is very high – we have seen a success rate that goes up to more than 70 % reduction of wireworm damaged potatoes (realized in exact trials of the Agricultural Research Institute LTZ Augustenberg of the State of Baden-Württemberg in Southern Germany).”
How does the capsules work?
Schaper says ATTRACAP® contains both an attractant (CO2) for Agriotes spp., and a fungus isolated in Germany – Metarhizium brunneum Cb15-III – with entomopathogenic properties. This fungus occurs throughout the world in soils and it is commonly applied in biological control agents.
“After the granules absorb moisture from the soil, the production process of the attracting agent and the growing of the fungus spores out of the granules begin. Attracted Agriotes spp. are infected after contact with the fungus and they die after several days depending on temperature and soil conditions,” Schaper says.
He points out that capsules are spread directly on the soil during planting, using a spreader for granules and mixed into an open furrow. Depending on weather and region this takes place between March and May in Germany. Since 2017 BIOCARE works on the regular European registration process to deliver not only the German and Austrian but the entire European market with their eco-efficient product.
More information on the ATTRACAP® capsules can be found on the BIOCARE website: biocare.de
This article was first published in the February issue of the Global Potato News magazine