War on pests: the mass production of a biological wonder weapon

As the noose tightens around maximum residue limits, a local biocontrol method seems the perfect solution. But the road to commercialising entomopathogenic nematodes for biocontrol has been littered with speed bumps. By Esté Beerwinkel.

Surrounded by binders on her desk, Sheila Storey sighs. “So far, nothing has been easy. But we’re getting there, I’m dogged.” In 2013, Storey started a process of converting research to innovation. As the owner of Nemlab and specialising in nematodes, the deciduous-fruit industry approached Storey to streamline the commercialisation of entomopathogenic nematodes (EPNs) for biocontrol.

“Role-players in the industry nudged me into approaching the Department of Science and Technology’s Technology Innovation Agency [TIA] for funding. Hortgro already provided R3.3 million for research, now they only needed an SMME [small, medium- and micro-sized enterprise] to complete the process—that’s where I jumped in and founded NemaBio. It was difficult and frustrating, but in December 2014 we received the grant funding.”

However, everything wasn’t smooth sailing from there onwards. And without this “doggedness,” Storey reckons she would’ve given up on the marketability of EPNs — but she believes in the product’s potential.

“What’s great about EPNs is that they actively seek and target pests. EPNs are attracted to the CO₂ [carbon dioxide] released by insects. Once released or sprayed onto the tree, they seek out the insect, infiltrate its body, and release a bacterium which rapidly multiplies and liquefies the insect’s insides. The nematode then feeds on the bacteria, exits the cadaver and moves on to the next CO₂-releasing sucker.

“Now, you may ask ‘so what?’ This whole process happens within 48 hours —and can deliver 80% mortality. No chemical does that.”

Two steps forward…

Working alongside researcher and EPN-trailblazer, Antoinette Malan, a formulation was achieved. And now, Storey remarks, they’re inching closer to EPN marketability.

“Currently, we mass produce EPNs in bioreactors or fermenters. Because it is a living organism, you have to formulate it — put it in a carrier to protect it and give it a shelf life. As all our research was done on fruit insects, we can only test and treat it at a certain time of the year — when the tree is dormant, and the insects are in the soil. Once this is completed, we do registration trials, because to sell something it has to go through Act 36 of 1947 [Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act]. That is a two-year process. When everything is done, we’ll compile a dossier of all the information, and from there onward the business will be sold on and the product will hit the shelves.”

But, Storey says, this process was delayed by a year when they realised their carrier was causing a health hazard.

“Originally, we intended to use mealworms as nematode carriers, but it caused a serious health hazard. The mealworms release faeces called frass, which is so fine it can get into your lungs — so we immediately halted that. Because we were back at square one and hanged something in our proposal, we went through a 14-month re-scoping process with TIA.”

While waiting for TIA’s approval, Storey experienced a flood of chaos. NemaBio’s nematologist resigned, the Council for Scientific and Industrial Research where some of the research was conducted, called them environmentally irresponsible and requested a biosafety ethical clearance before “the EPNs kill all the bees” — this took three months and they missed their window for testing, delaying the process for another year. But, despite all the hiccups, Storey stuck it out, and triumphed.

“We have our formulation. It’s a natural inert material, a clay-type material combined with a couple of other products added to it. The registrar is very excited about our product, as he’s also keen to register a local biocontrol method. We need to stop importing products.

“The EPN we’re reproducing is Steinernema yirgalemense. The species was first described from Yirgalem, Ethiopia. But it’s also endemic to South Africa, as Antoinette discovered in soil samples taken in Mpumalanga. We chose S. yirgalemense as it gives the best results — 80 to 100% mortality — across all insects.

“If registration goes to plan — we’re registering the product for false codling moth on citrus, codling moth on apples and weevil on vines — we’d be able to stop these pests before they can spread. EPNs target these insects before they can emerge, while they’re still stationary. This way you reduce inoculum. Once the pest is a flying object, it’s near impossible to control it as you’re only targeting it where you spray.”

Times are a-changin’

Storey cautions growers against using imported EPNs, as they can cause more harm than good. “Many growers use EPNs imported from Europe, but these nematodes — specifically S. feltiae — disrupts the local biodiversity and is detrimental to soil health. Heterorhabditis bacteriophora has the potential to work safely and efficiently, but it has to be applied correctly.”

While using EPNs for biocontrol holds great benefits, Storey asserts that it will require some patience and effort from growers. “The industry has changed from what I call ‘spray and kill,’ things are different now — you have to think about what you’re doing. MRLs [maximum residue levels] continue to be a growing concern, and while the integrated pest management initiative addresses this, the pinch will only become greater. Even big agro-chemical companies are chasing biological control because they know times are changing.

“Before reaping the benefits of this product, growers will need to realise EPNs are living organisms, and they have restrictions. EPNs are sensitive to ultraviolet light and desiccation, so you can only spray in the morning or evening. Initially it also won’t be a cheap product. So far, we focused on getting the production and formulation right — not using the cheapest products. Luckily, through our bilateral agreement [a research collaboration] with India, we’re working with chemical engineer Prasanna Belur from the National Institute of Technology Karnataka, Mangalore. Prasanna is currently exploring cheaper, alternative materials for our product.”

Testing

According to Storey, there are still a few hurdles to cross, but EPNs could be ready for sale in the next three years. “The entire process, including registration, is five years. There are legal hoops to jump through and you can’t take any shortcuts with your product.

“This September we do our first trials, which will be repeated in 2019. Thereafter, we compile the dossier for the registrar, and if all goes well, we’ll be able to sell the business to an investor by 2020 and have the product on our farms in 2021.”

Storey says she knows the lagging process is an irritant for growers, but testing and registration is non-negotiable. “I realise growers need to solve their issues. But although it’s a natural product, we need to be sure our product works — to protect the farmers and our existing export markets.”

EPNs might not be a quick fix yet, Storey reckons, but it’s an imminent one.