Personal Narratives: Ruth Kihika and Fairo Dzekashu

TWO icipe PhD scholars narrate their journeys in science and their research at icipe, its contribution to the sustainable development goals and COVID-19 pandemic recovery journey.

Ruth Kihika-Opanda (Kenya)

PhD scholar, ARPPIS

I was born in Nairobi, where I spent my early years. When I was  nine years old my family relocated to our rural home in Murang’a County, about 50 kilometres north of Nairobi, the capital city of Kenya. 

My inspiration into science started when we moved upcountry. Initially, I was disillusioned by the infrastructural inequalities between urban and rural schools. Little did I know that it would be within these disparities that my passion for science would be ignited. This impetus was due to one of my primary school teachers who used to create science experiments using locally available materials, for example inventively demonstrating differences in air pressure using water, a plate, a matchstick and a glass. His ingenuity made science interesting and relatable. My enthusiasm for sciences continued through the encouragement of one of my high school teachers, hence the decision to pursue a BSc degree in Chemistry, which I obtained from Moi University, Kenya, in 2008.

In 2013, I enrolled for an MSc at Kenyatta University, Kenya, where Prof. Ahmed Hassanali,  my Organic Chemistry Lecturer introduced me to Chemical Ecology, a scientific discipline that interlinks chemistry with biology and ecology, cutting across fields like health and agriculture.  Prof. Hassanali also connected me with Prof. Baldwyn Torto, Head of the icipe Behavioural and Chemical Ecology Unit (BCEU), leading to an opportunity to undertake my MSc research project at the Centre. I investigated the chemical communication of root-knot nematodes – parasitic worms that use plants as hosts, obtaining their name from the ability to infect and cause galls (swellings or knots) in plants. The nematodes feed on, and develop in the galls, in the process impeding nutrient and water uptake by the host plant resulting in poor growth and crop yield. Additionally, such damage increases the severity of opportunistic infections from other soil pathogens. Several methods, including crop rotation, use of resistant cultivars, biological control and nematicides are used to control root-knot nematodes. Fumigant nematicides, the most promising, are no longer used due to their ozone-depleting properties. As such, there is an urgent need for sustainable solutions to control root-knot nematodes.

Our research identified the chemical signals involved in the interaction between Meloidogyne incognita, one of the most damaging root-knot nematodes species, and a variety of pepper plants grown in East Africa. Although previous studies have shown that roots of host plants may attract or repel nematodes, ours was the first to establish the mediating chemicals. The findings, published in Scientific Reports (an online multidisciplinary, open access journal from the publishers of the highly prestigious Nature journal), present new opportunities for breeding peppers that are resistant to root-knot nematodes. (Paper link)

 Conducting this research reminded me of my grandmother’s often unrewarded toil on her farm, and I was able to identify pests as the main culprit in this scenario. As such, studying nematodes,  one of the most important agricultural pests, was a natural fit for me. Therefore,  through Prof. Torto’s support, I enrolled for a PhD under the icipe African Regional Postgraduate Programme in Insect Science (ARPPIS), funded by the German Academic Exchange Programme (DAAD), in a project supported by the United States Department of Agriculture/Agricultural Research Service (USDA/ARS).

My PhD research focusses on understanding the chemical signaling of root-knot nematodes looking at host and non-host plants. So far, we have identified chemical signals associated with nematode infection, mainly small molecules from tomato root exudates that disrupt the ability of the nematodes to detect a host plant. These natural chemicals can be used to develop plant varieties that are resistant to root-knot nematodes. They can also  be applied in soil as repellents to mask odours that attract nematodes in susceptible host plants and thus protect the crops from nematode infection. These findings have been published in the Journal of Agricultural and Food Chemistry, a reputable journal of the American Chemical Society. (Paper link)

I have also identified specific changes of odours in the plant shoots occasioned by nematode infection in the roots. This implies that infection by root-knot nematodes may also influence above-ground pest populations. Further research is needed to determine how these compounds can be leveraged to control various plant pests. Also, I have found chemical components in plants that nematodes do not use as hosts, which can be used to suppress these pests.  

Our studies contribute to the African, and indeed global quest, for science-led knowledge as a basis for improved agriculture and more resilient food systems towards attainment of the sustainable development goals (SDGs),  and recovery from the impacts of the COVID-19 pandemic on livelihoods.

Being at icipe has pivoted my career as a young researcher, through world class training and skills, as well as international networks. For instance, I have presented my research findings at international conferences and meetings including: the Entomological Society of America Virtual Annual Meeting in 2020, the XIX International Plant Protection Congress in 2019, Hyderabad, India, and the International Society of Chemical Ecology 2018 Annual meeting in Budapest, Hungary. Additionally, I have received several awards like the icipe Governing Council, Best published science paper by an icipe scholar in 2017, first runner-up, L'Oreal-UNESCO for Women in Science Sub-Saharan Africa Young Talents Award, 2019, and I have been selected a fellow of the Mawazo Learning Exchange (MLEx) fellowship, 2021 cohort.

My future career plans are based on my dual experience of rural and urban life, which has shaped my understanding of the challenges faced by farmers, especially women, including access to farming inputs and markets. I am also conversant with the obstacles young graduates face in securing job opportunities. My goal is to excel and serve as a role model for aspiring scientists, to contribute to the advancement of Chemical Ecology in Africa, and the development of sustainable and environmentally friendly agricultural solutions.

My key mentors  and supporters have been my family, especially my father who encourages me to aim extremely high and to always autograph my work with excellence. My late grandmother bequeathed to me the example of personal service and dedication, for society transformation. As a champion of the Green Belt Movement, founded by the late Kenyan Nobel Peace Prize winner, Professor Wangari Maathai, she mobilised her community to adopt agroforestry. As a mother of two boys, the unconditional support of my husband has been invaluable in my academic journey.

Also, I have been fortunate to have a team of internationally renowned scientists as my mentors: Prof. Ahmed Hassanali who first exposed me to Chemical Ecology,  has contributed immensely to the field through his phenomenal research. Prof. Baldwyn Torto, an exceptional scientist who has shared his wisdom, continues to support my career growth and challenges me to have a global perspective as an upcoming scientist. Dr Margaret Ng’ang’a, my MSc and PhD supervisor and Dr Lucy Murungi, who began the nematode research group in BCEU, have been great role models and they epitomize excellence as women in science. Dr David Tchouassi, my PhD supervisor has also been resourceful through all my research activities.

Fairo Dzekashu Foryuy (Cameroon)

PhD scholar, ARPPIS

Fairo Dzekashu Foryuy (Cameroon), and ARPPIS PhD scholar in the Environmental Health Theme discusses his ongoing research, which so far suggests that seasonal variation in rainfall and more homogeneous plant communities due to global change could lead to a loss of bee diversity on the bee diversity in the Eastern Afromontane Biodiversity Hotspots.

I was born in Kumba City, the capital city of Meme, a department of the South-West Region of Cameroon. Because of my father’s job as a journalist, we moved around the country very much.

My inspiration for science was definitely my mother, who is a professor of Medical Parasitology. When I was about 14 years old, she introduced me to the National Geographic television channel and I was mesmerised by it;  I did not watch anything else (except football!). Growing up, I developed a deep attraction to nature, and I participated in several wildlife study expeditions abroad. On one such trip in Cameroon, in early 2014 just after completing my BSc in Zoology and Animal Physiology from the University of Buea, Cameroon. I encountered researchers from the Ecology Department, Charles University, Prague, Czech Republic. They introduced me to the concept of pollination biology. I was intrigued and choose this topic as the focus of my MSc in the Department of Zoology and Animal Physiology, specialising in Entomology, which I obtained from the University of Buea in 2017.

I joined icipe due to Professor Eric Fokam from University of Buea, who had been through the ARPPIS programme. After completing my MSc studies, I applied to the programme.

My research focus is on understanding plant-bee pollinators diversity and interaction networks in the Eastern Afromontane Biodiversity Hotspot, one of the most biologically rich yet threatened areas around the globe. We have conducted a study on two mountain ranges Taita Taveta, southeastern Kenya, and Murang’a on the slopes of the Aberdares mountains in central Kenya, to understand the contribution of seasonality to the elevational diversity gradient of bees. Due to benign temperature conditions throughout the year, insect communities on tropical mountains are often assumed to be relatively unaffected by seasonality effects. However, we found that the seasonal turnover in bee communities significantly contributed to the total number of species found across the year. The seasonal turnover decreased with elevation, shaping the diversity gradient along the mountain slope. We linked the seasonal change in bee communities to two drivers: a turnover in flowering plant communities and seasonal changes in the level of precipitation across the year. These results suggest that a potentially reduced seasonal variation in rainfall and more homogeneous plant communities during global change could lead to a loss of bee diversity on mountains in East Africa. With 185 species of bees detected feeding on more than 300 species of plants, we underpin the high conservation value of regrowth vegetation for the protection of the unique bee diversity on the Eastern Afromontane Biodiversity Hotspots. We also think that these results would advance our understanding of seasonality in insect communities of tropical mountains.

This research contributes to the sustainable development goals 13 Climate Action and 15 Life on Land. It also supports post-COVID-19 pandemic thinking because it provides an understanding of biodiversity and conservation as neglected aspects. Biodiversity contributes to the maintenance of several ecosystem services. Human existence depends on the pollination of food crops and wild plants, carbon sequestration, prevention of soil erosion and extreme weather, and nutrient cycling. The annual economic value and contribution of biodiversity and ecosystem services are estimated at USD 140 trillion. The loss of biodiversity is considered a significant driver in the emergence of infectious diseases. Hence, understanding human interaction with the ecosystem is vital for detecting and preventing disease outbreaks. Climate change and land-use changes affect the various ecological processes that keep a check on diseases. Understanding the complexity and diversity of vegetation concerning climate change and human pressure will help us determine the compositional range and the diversity and abundance of disease vectors. In turn, this will guide much needed stringent measures on restoration, biodiversity and conservation, climate change, land-use and advocacy control for the sustainable use of natural resources in preventing future pandemics.

My career plan is to develop my expertise in pollination ecology, biodiversity and conservation, which is inadequate in my country, Cameroon and the African continent. I would love to continue research, training students, and mobilising communities by developing and executing location-specific projects. This, I believe, will emancipate communities, create awareness on the ecosystem services of pollination and conservation in general.

My key influence has always been my mother. She is a superwoman. Her dedication to her work inspires me very much, and she has motivated and encouraged me throughout my life. Dr Štěpán Janeček, a professor and researcher from the department of ecology, Charles University, Prague, Czech Republic, was my mentor during my MSc. His research on pollination and ecology is phenomenal. He was drilling me through the entire process of pollination and ecology. Finally, the dedication and advice of  Dr Michael Lattorff, icipe Senior Scientist, Bee Health, has inspired and impacted my work very much.