FEUDJIO THIOMELA Riccado

Background

FEUDJIO THIOMELA Riccado is a PhD candidate and Research Assistant at CRID. He holds a Master’s degree in Parasitology and Ecology from the University of Yaoundé I, where his academic journey centered on exploring host–parasite interactions within tropical forest ecosystems. His growing interest in applied entomology led him to join the Agricultural Research Institute for Development of Cameroon (IRAD), specifically within the entomology department. Under the supervision of Professors Luc Dibog and Raymond Mahob, Riccado conducted an extensive field study examining the impact of Sahlbergella singularis Haglund trophic bites on the productivity and decline of different genotypes of Theobroma cacao L. in southern Cameroon. This research provided significant insights into cocoa production challenges in the region, notably: • Genotype-dependent production losses, primarily due to the abortion of young fruits (cherelles). • Cases of partial or total cocoa tree decline, associated with the combined effects of trophic bites and secondary infections by opportunistic fungi. Through this work, Riccado contributed to a deeper understanding of pest–plant interactions in cocoa agroecosystems, highlighting both the ecological and economic implications for sustainable agriculture in Cameroon.

Research

Riccado Thiomela’s research centers on the biology and control of Anopheles mosquitoes, the primary vectors of malaria. His work addresses one of the most pressing challenges in vector control: insecticide resistance. By investigating physiological, genetic, and behavioral adaptations that reduce the effectiveness of pyrethroids and other compounds widely used in public health, he highlights the mechanisms that compromise the efficacy of current interventions. Through experimental hut trials and laboratory assays, Riccado rigorously evaluates the performance of innovative vector control tools, including insecticide-treated nets and next-generation indoor residual spraying formulations. These studies contribute directly to the development of evidence-based malaria prevention strategies, ensuring alignment with World Health Organization (WHO) recommendations and strengthening global efforts to reduce malaria transmission. A second line of his research focuses on the morphological and molecular identification of mosquitoes. Recognizing the importance of accurate species identification for surveillance and control, Riccado designs and refines Standard Operating Procedures (SOPs) and training modules that enable technicians and students to reliably distinguish Anopheles from other genera such as Culex or Aedes. By structuring clear identification keys and defining roles within training programs, he enhances entomological surveillance capacity and ensures consistency of practices across both field and laboratory teams.

• Areas of interest:

Throughout his career, FEUDJIO THIOMELA Riccado has cultivated a strong interest in disease vector control, driven by the urgent need to mitigate the impact of vector-borne diseases on public health and socio-economic development. His work integrates expertise in biology, ecology, genetics, and entomological surveillance, allowing him to approach vector management from multiple scientific perspectives. He is particularly engaged in: • Understanding vector biology and ecology, to anticipate patterns of transmission and guide control strategies. • Investigating genetic and physiological mechanisms of resistance, ensuring that interventions remain effective against evolving mosquito populations. • Strengthening entomological surveillance systems, by designing tools and protocols that improve accuracy and consistency in field and laboratory settings. • Translating scientific findings into applied solutions, aligning research outcomes with public health priorities and sustainable development goals..

• An overview of research areas:

Vector biology, ecology, insecticide resistance, Insecticide resistance management, vector genetic, entomological surveillance, vector control strategy

 

Other Relevant  Expertise, Professional Memberships

1.       Cameroon Biosciences Society (CBS), 2.       Pan-African Mosquito Control Association (PAMCA).

 

• Supervisors

Prof. Wondji Charles (LSTM) Prof. Mahob Raymond (UY1) Prof. Fomena Abraham (UY1) Bench supervisors Dr Tchouakui Magellan (CRID)

Dr Menze Benjamin

• Research groups

-Member of Wondji Research Unit (WoRu) at CRID

• Publications

  • 1.  Mahob, R. J., Feudjio Thiomela, R., Dibog, L., Babin, R., Fotso Toguem, Y. G., Mahot, H., … & Bilong Bilong, C. F. (2019). Field evaluation of the impact of Sahlbergella singularis Haglund infestations on the productivity of different Theobroma cacao L. genotypes in the Southern Cameroon. Journal of Plant Diseases and Protection, 126, 203-210.https://link.springer.com/article/10.1007/s41348-019-00221-z 2.      Etam, P. B. N., Mahob, R. J., Massé, P. S. M., Baleba, L., Feudjio, R., Mboutngam, M. M., … & Bilong, C. F. B. (2023). Field Assessment of Cocoa Dieback Due to the Neglected Mosquito True Bug, Helopeltis sp. (Hemiptera: Miridae) and Associated Pathogenic Fungi Infections in Southern Cameroon. International Journal of Agricultural Science, 8. https://www.iaras.org/home/caijas/field-assessment-of-cocoa-dieback-due-to-the-neglected-mosquito-true-bug-helopeltis-sp-hemiptera-miridae-and-associated-pathogenic-fungi-infections-in-southern-cameroon 3.      Tchouakui, M., Thiomela, R. F., Nchoutpouen, E., Menze, B. D., Ndo, C., Achu, D., … & Wondji, C. S. (2023). High efficacy of chlorfenapyr-based net Interceptor® G2 against pyrethroid-resistant malaria vectors from Cameroon. Infectious Diseases of Poverty, 12(1), 81. https://pubmed.ncbi.nlm.nih.gov/37641108/  4.      Thiomela, R. F., Tchouakui, M., Menze, B. D., Nchoutpouen, E., Ngongang-Yipmo, E. S., Wood, O., … & Wondji, C. S. (2024). Indoor residual spraying of experimental huts in Cameroon highlights the potential of Fludora® Fusion to control wild pyrethroid-resistant malaria vectors.BMC infectious deseases. 5.      Magellan Tchouakui; Sulaiman S. Ibrahim; Mersimine K. Mangoua; Riccado F. Thiomela; Tatiane Assatse; Sonia L. NgongangYipmo; Abdullahi Muhammad; Leon J. M. Mugenzi; Benjamin D. Menze; Themba Mzilahowa; Charles S. Wondji (2024). Substrate promiscuity of key resistance P450s confers clothianidin resistance whilst increasing chlorfenapyr potency in malaria vectors. Current Biology. 6.      Carlos S. Djoko Djoko Tagne; Mersimine F. M. Kouamo; Magellan Tchouakui; Abdullahi Muhammad; Leon J.L. Mugenzi; Nelly M.T. Tchatchoua; Riccado F. Thiomela; Mahamat Gadji; Murielle J. Wondji; Jack Hearn; Mbouobda H. Desire; Sulaiman S. Ibrahim; Charles S. Wondji (2024). A single mutation G454A in P450 CYP9K1 drives pyrethroid resistance in the major malaria vector Anopheles funestus reducing bed net efficacy.  Current Biology. 7.      Ngongang-Yipmo ES, Tchouakui M, Menze BD, Thiomela RF, Fofie D, Ngannang-Fezeu VB, Mugenzi JL, Njiokou F, Wondji CS. Long-term impact of exposure to Royal Guard, a pyriproxyfen-based bed net, on pyrethroid-resistant malaria vectors from Cameroon using DNA-based metabolic resistance markers. Pest Manag Sci. 8.      Ambrose Oruni, Benjamin D. Menze, Yvan G. Fotso-Toguem, Vanessa B. Ngannang-Fezeu, Riccado F. Thiomela, Magellan Tchouakui, Jack Hearn, Jonathan Kayondo, Charles S. Wondji (2025).  Breaking the Resistance Barrier”: Superior Efficacy of Chlorfenapyr Bednets Against Highly Resistant Anopheles malaria vectors in Uganda.