Portrait Ralf Nauen

From Child Bug Collector to Insect Researcher

How do insect pests develop resistance to crop protection agents? Dr. Ralf Nauen is on the hunt for answers.


When caterpillars, beetles or aphids attack fields and no crop protection agent can stop them, it’s time for me to step in. All the time, new, powerful insecticides are being developed, but, unfortunately, insect pests can adapt to them. This means they can rapidly develop biological mechanisms that make insecticides less effective. As an insect toxicologist at Bayer, my focus is these resistance mechanisms in crop pests. Alongside my team, I study how modern insecticides end up becoming ineffective against some of these voracious insects. It’s an ur-gent issue: When this happens, there’s a risk of massive crop losses. Overall, the development of insect resistance is one of the greatest challenges facing modern farming.

I’m just as fascinated by my work as I was 30 years ago.

Dr. Ralf Nauen
Principal Scientist, Research & Development, Crop Science Division

I see it as our responsibility to develop knowledge about this situation. Today, many external researchers get in touch with us because of our proactive approach. As a result, we’re establishing an outstanding network – and we’re all gaining valuable new insights. I’m proud to say that our resistance research unit is one of the top world addresses in the field of pest control.

My colleagues and I have long focused on this topic. For my own doctoral thesis, I studied how insects absorb, metabolize and eliminate certain active ingredients. Today, thirty years later, I’m just as fascinated by this work. The differences are that the research questions have changed, and the responsibility has in-creased. One important requirement, for instance, is that insecticides must not harm bees. Pollinators like bees can also suffer from the effects of an insecticide if it’s used incorrectly. To protect bees, we study what distinguishes them, on a molecular level, from other insects. An insecticide’s active ingredients must at-tack target structures in insect pests in order to avoid harming beneficial insects like bees. When we know what these target structures are, then we can subject crop protection substances to much better tests to determine if they’re safe for bees. As a result, we can develop modern insecticides that have a more targeted effect.




Research, whether it’s in a lab or on a field, is a never-ending process. Working with my team in a lab is my professional passion. And field research isn’t just a job; nature has always been my hobby. As a child, I was fascinated by insects, and I spent a lot of time outdoors collecting specimens. Today, I combine this recreational activity with another passion of mine, hiking, with my wife. I’m al-ways on the go.


CV Dr. Ralf Nauen

Dr. Ralf Nauen is an insect toxicologist/biochemist working in R&D at Crop Science Division of Bayer AG in Monheim, Germany working on functional (toxico)genomics, fundamental and applied aspects of insecticide/acaricide mode of action and detoxification, as well as biochemical and molecular mechanisms of insecticide resistance and its management by state-of-the-art technologies. He received his PhD from the University of Portsmouth (UK) for his work on the pharmacokinetics and toxicodynamics of systemic insecticides. He is a Bayer Distinguished Science Fellow (highest scientific grade awarded by the company) and in 2013 he was awarded to become Fellow of the Entomological Society of America (for outstanding contributions in the field of Entomology) and in 2014 he received the prestigious ACS (American Chemical Society) International Award for Research in Agrochemicals, in recognition of his outstanding and influential research into insecticide and acaricide modes of action and resistance. He is author of more than 200 peer-reviewed scientific papers and book chapters with more than 12,000 citations. He is also university lecturer in Agricultural and Molecular Entomology at the University of Bonn, Germany, and appointed Visiting Professor by the Chinese Academy of Agricultural Sciences (CAAS, Beijing). He supervised many PhD students and served for 5 years as Chairman of IRAC (Insecticide Resistance Action Committee). Since many years Dr. Nauen serves as an Executive Editor of the well-known international journal Pest Management Science, in addition he is Editorial Board member of several scientific journals.


Selected Publications

A resistance mutation conserved between insects and mites unravels the mode of action of benzoylurea and chitin biosynthesis inhibitors.
Proceedings of the National Academy of Sciences U.S.A 113, 14692-14697
Douris V, Steinbach D, Panteleri R, Livadaras I, Pickett JA, Van Leeuwen T, Nauen R, Vontas J (2016)

Unravelling the molecular determinants of bee sensitivity to neonicotinoid insecticides.
Current Biology 28, 1137-1143
Manjon C, Troczka BJ, Zaworra M, Beadle K, Randall E, Hertlein G, Singh KS, Zimmer CT, Homem R, Lueke B, Reid R, Kor L, Kohler M, Benting J, Williamson MS, Davies TGE, Field LM, Bass C and Nauen R (2018)

New approaches to old problems: removal of phospholipase A2 results in highly active microsomal membranes from the honey bee, Apis mellifera.
Pesticide Biochemistry and Physiology 161, 88-76
Zaworra M and Nauen R (2019)

The alfalfa leafcutter bee, Megachile rotundata is more sensitive to N-cyano neonicotinoid and butenolide insecticides than other managed bee pollinators.
Nature Ecology & Evolution 3, 1521-1524
Hayward A, Beadle K, Singh KS, Exeler N, Zaworra M, Almanza MT, Nikolakis A, Glaubitz J, Bass C and Nauen R (2019)

Molecular characterization of Cry1F resistance in fall armyworm, Spodoptera frugiperda from Brazil.
Insect Biochemistry and Molecular Biology 116, 103280
Boaventura D, Ulrich J, Lueke B, Okuma D, Gutbrod O, Geibel S, Zeng Q, Dourado PM, Martinelli S, Flagel L, Head G and Nauen R (2020)