David Grzywacz, former head of NRI’s Agriculture, Health & Environment Department, passed away on 17 January at the age of 70. Friends and colleagues remember him as a great colleague, mentor, jolly friend, pragmatist and a pioneer in his field.
Dave joined the Natural Resources Institute in 1990 as a senior scientist and insect pathologist after working at the Centre for Overseas Pest Control since 1979. He was head of the insect pathology research group in 1993, the sustainable agriculture group in 2003, and the Agriculture, Health & Environment Department in 2005–06. At the time of his retirement, he was deputy programme leader for the MSc in Sustainable Environmental Management (now MSc Global Environmental Change) and MSc Sustainable Agriculture (now MSc in Agriculture for Sustainable Development).
Some of his major contributions were in the development of commercial biological pesticides based on insect viruses to control global and emergent pests. For example, Dave was instrumental in developing and evaluating a method for biological control of fall armyworm, published in 2006. Additionally, he was a major contributor to the first ever paper on the role of Wolbachia (a group of insect infecting bacteria) in mediating virus infections. By showing that Wolbachia made fall armyworm more susceptible to viral infections rather than protecting them, this work had implications for biological control of insect pests particularly by using insect virus-based biopesticides.
Along with Lancaster University’s Professor Ken Wilson, Dave was also a co-inventor on a patent, “Organic particles containing viral bodies GB2541175” – an invention with the potential to make insect virus- based biological control a commercially competitive alternative to synthetic pesticides. A significant barrier to the broader adoption of biopesticides is their vulnerability to ultraviolet radiation from sunlight, which reduces their longevity and effectiveness. Dave and Ken’s how to protect biopesticide from degradation by ultraviolet radiation.
‘Dave and I first started working together around 25 years ago, initially in Tanzania and then later in the UK. He was an expert in insect viruses, specifically baculoviruses, and how they could be applied as biocontrol agents against crop pests,’ Professor Wilson said. ‘He wrote many impactful papers and book chapters on baculoviruses and their application. Our work together also resulted in two patents related to a novel method of formulating baculoviruses that would enhance their efficacy and shelf life. He was an excellent scientist and friend and will be sorely missed.’
Dave was keen on translating agricultural research into greater real impact in developing countries. ‘Dave and I had a series of projects together in Nepal working on chickpeas from 2000-2006. He was a fantastic colleague and great companion – not only so knowledgeable but also a pragmatist and able to get things done,’ said Phil Stevenson, Professor of Plant Chemistry and Head of the Chemical Ecology and Plant Biochemistry Group at NRI. Professor Stevenson added, ‘He was also a scientist of great integrity – always willing to credit collaborators and coauthors appropriately and recognise the contributions of overseas partners.’
He was a trusted advisor to emerging companies in Kenya, Ghana, and Tanzania, guiding them in the production of biological pesticides. ‘Our research took us to many countries including Kenya, Ghana, Tanzania, India and Thailand to name a few’ said Mark Parnell, Head of Commercial Operations at NRI. ‘Dave provided scientific advice to companies and governments in all these countries, securing the release and sale of several biological pesticide products, adding to the availability of sustainable and environmentally friendly biopesticides across the world,’ he said. Mark started working with Dave in 1990 when he joined NRI as an Assistant Scientific Officer. They worked on several major crop pests researching biological control methods of the African Armyworm, Diamondback moth and cotton bollworm, mostly using insect viruses as part of Integrated Pest Management strategies.
Dave was a fellow of the Royal Entomological Society and a member of the Society of Invertebrate Pathologists. He was also a reviewer for several scientific journals including Biological Control, Journal of Pest Science, African Journal of Agricultural Research, Experimental Agriculture, Crop Protection, Pesticide Chemistry and Physiology, Entomological Research, and Journal of Insect Science.
He was always cheerful and loved a joke. Professor Stevenson recalled one example: ‘Dave once drafted a seemingly serious concept note for managing rhinos in Nepal's Terai region where they are a big problem for farmers living close to Chitwan game reserve. The "sustainable" solution he submitted for approval involved having then NRI director John Perfect’s jazz band to play and frighten the rhinos back to the forest. I can still hear his infectious laugh now.’
Dave’s work and dedication to his field have left an indelible mark on the institutions he served and the many colleagues who had the privilege of working alongside him. His legacy will continue to inspire and influence the field for years to come.