Novel biopesticides by Rhodes researchers take flight

Chemical pesticides have been in use since the late 1800s to protect crops, but their harmful effects on the environment and human health have led scientists to search for alternatives. In South Africa, two PhD students from Rhodes University have had a breakthrough. Ground-breaking research by Tamryn Marsberg and Michael Jukes has led to the development of two viral-based biopesticides, MultiMax and CodlMax, as alternatives to the conventional use of chemical pesticides on citrus, apples, and litchi. Biopesticides are biological pesticides like viruses, fungi, bacteria and nematodes that are natural predators of insects. In an interview with BizNews, Dr. Jukes said that, working with the university’s research partner Citrus Research International and an industry partner River Bioscience, a global patent has been completed and the products have been launched for commercial use in Africa and Europe. He said they are hoping that their products will soon be able to enter the Indian market and North American markets, where the codling moth is a major pest for apples. –  Linda van Tilburg


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Excerpts from the interview

Overuse of Chemical Pesticides Can Have Detrimental Effects

Chemical-based pesticides are used to control many different pests in various crops around the world. It’s not so much the use of chemical pesticides, but I guess when they are overused and when they are used in ways that are not necessarily going to be helpful for the control of those pests. So, when you overuse a chemical, you could have a wash of those chemical insecticides into our waterways or other types of environments which can then have detrimental effects. So, this could have a knock-on effect for beneficial insects in the environment such as bees and birds or other animals. This is really where the careful consideration of how we control pests becomes so important, and especially when it comes to chemicals to make sure we manage them correctly and use them appropriately where necessary.

Then, of course, to find new ways that we can control insects while we try to balance out our use of these different control options. I don’t have an exact number, but they are used extensively because they are very effective and they offer a faster way of controlling pests in farms and in different agricultural environments. It is in many developing countries that they use quite extensively because they’re cheaper, they’re more effective, and they’re fast to use, but of course, this comes with the cost of what effect it has on the environment and other organisms in that environment. So, where possible we really should be trying to say, well, even if they’re not used extensively, what other applications can we use to balance this out because for example, resistance to these insecticides can also creep up if you overuse them. Even where they are being used in an appropriate fashion, if they’re used too often or too frequently, you could have resistance developing. So, we need to try to balance those out with the use of different control options to ensure that we aim for a long-term control programme. 

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How the new biopesticides were discovered

It started with myself and a colleague of mine, Tamryn Marsberg; we were both pursuing our PhDs at the time. She began researching an insect known as the leaching moth, searching for viruses that could be utilized for control or further development. After establishing an insect rearing program at Rhodes University, she successfully isolated a virus and initiated research on it. Shortly thereafter, another insect species we were studying at the university began exhibiting signs of infection, leaving us puzzled. To gain more insights, we sent samples to our collaborators in Poland, asking them to investigate further. They indeed detected signs of a virus within that insect, and it was then designated as my Ph.D. project. Tamryn and  I were simultaneously investigating two different insects, both afflicted by viral infections, presenting the potential for pesticide development. We continued our research journey from there, and that’s where the story took shape.

A biopesticide to help apple, macadamia, citrus and litchi farmers

The virus that proved effective infects various insects that commonly cause damage to citrus, apple, macadamia, and other crops. Our initial discovery involved locating this virus within these insects. Subsequently, through collaboration with our research partners and industry associates, it underwent an extensive development process, eventually culminating in the creation of two distinct products. One of these products is named CodlMaxl, specifically designed for controlling the codling moth, a significant pest affecting apple crops. Codling moths are major threats in South Africa, Europe, and North America.The second product, MultiMax, is based on the same virus but features slight variations in its formulation. MultiMax will be employed to combat pests such as the false codling moth, a major pest in South African citrus production, as well as in macadamia and litchi cultivation. Consequently, it exhibits applicability across a range of different crops and targets.

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Shipments of biocides has started, available to farmers  

We have made this announcement as our products have officially entered the market. The initial batch of products, in collaboration with our commercial partners at River BioScience, based in South Africa, has begun their shipments to farmers within the region. Currently, we have a pending registration process for sales in Europe, and we are optimistic that this process will be completed very soon. This will enable these products to expand their reach to other countries where they can effectively address pest issues. However, for the time being, these products are already available for purchase in South Africa and will be utilized by farmers in the near future to combat these pests.

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