Dennis Obonyo

Dr. Dennis Obonyo

Biopesticides Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Wernher & Beit Bldg (South), UCT Campus, Anzio Road Observatory, Cape Town 7925, South Africa
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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2022 in Sustainability
Verified
Journal Article
Open access
PDF file
CACHRISTINE ABEY ASHAOLU
CHRISTINE ABEY ASHAOLU
Chibuzor Onyinye OkonkwoChibuzor Onyinye Okonkwo
Chibuzor Onyinye Okonkwo
ENElizabeth Njuguna
Elizabeth Njuguna
Dennis ObonyoDennis Obonyo
Dennis Obonyo
The global trend towards increased demand for organic food, greener environments, and the integration of biological control agents into pest management strategies has greatly enhanced the need for biopesticides. Biopesticides are made from micro-organisms or other natural substances and are, hence, generally environmentally friendly. However, despite their great potential—and in part due to regulatory challenges—relatively few biopesticides have been registered and commercialised in Nigeria compared to other African countries, such as South Africa and Kenya. Biological active agents are so diverse that applying the same safety standards to all of them is almost impossible. A comparative review of risk assessment processes of Nigeria’s biopesticide regulations with other developing African countries (South Africa and Kenya) and developed regions (the European Union and the United States of America) was conducted. Prolonged field testing, lack of bridged risk assessments, and technical checklists were identified as key factors hampering the research and development of biopesticides in Nigeria. Suitable amendments to the existing regulations guiding biopesticide formulation and utilisation in Nigeria are recommended. Risk assessment matrices for microbial and biochemical pesticides and a scientific/technical checklist have also been developed. It is apparent that harmonisation and data exchange among countries in the region could enhance the advancement of scientific and technical knowledge for sustainable regulation of, and cross-border trade in, biopesticides.

10 April 2018 in Frontiers in Bioengineering and Biotechnology
Verified
Journal Article
Open access
PDF file
Dennis ObonyoDennis Obonyo
Dennis Obonyo
MWMichael Wach
Michael Wach
PRPatrick Rüdelsheim
Patrick Rüdelsheim
WCWendy Craig
Wendy Craig
Anyone working in biosafety capacity enhancement faces the challenge of ensuring that the impact of a capacity enhancing activity continues and becomes sustainable beyond the depletion of funding. Many training efforts face the limitation of one-off events: they only reach those people present at the time. It becomes incumbent upon the trainees to pass on the training to colleagues as best they can, whilst the demand for the training never appears to diminish. However, beyond the initial effort to establish the basic content, repeating capacity enhancement events in different locations is usually not economically feasible. Also, the lack of infrastructure and other resources needed to support a robust training programme hinder operationalizing a “train-the-trainer” approach to biosafety training. One way to address these challenges is through the use of eLearning modules that can be delivered online, globally, continuously, at low cost, and on an as-needed basis to multiple audiences. Once the modules are developed and peer-reviewed, they can be maintained on a remote server and made available to various audiences through a password-protected portal that delivers the programme content, administers preliminary and final exams, and provides the administrative infrastructure to register users and track their progress through the modules. Crucial to the implementation of such an eLearning programme is an approach in which the modules are intentionally developed together as a cohesive curriculum. Once developed, such a curriculum can be released as a stand-alone programme for the training of governmental risk assessors and regulators or used as accredited components in post-graduate degree programmes in biosafety, at minimal cost to the government or university. Examples from the portfolio of eLearning modules developed by the International Centre for Genetic Engineering and Biotechnology (ICGEB) are provided to demonstrate these key features.

29 August 2024
Verified
Book Chapter
Open access
PDF file
Kahsay Tadesse MawchaKahsay Tadesse Mawcha
Kahsay Tadesse Mawcha
GKGrace Kinyanjui
Grace Kinyanjui
SSStella W. Simiyu
Stella W. Simiyu
Olubukola Oluranti BabalolaOlubukola Oluranti Babalola
Olubukola Oluranti Babalola
Dennis ObonyoDennis Obonyo
Dennis Obonyo
Biopesticides include living organisms or products derived from natural sources, like genes and metabolites or natural-identical synthetic sources, that can be used to control pests. They are valuable pest management tools in sustainable agriculture. They protect crops from a wide range of pests and diseases while exhibiting specificity against target organisms and with minimal environmental impact. Incorporation of biopesticides into integrated pest management (IPM) programs provides a more holistic approach for growers to maximize crop yields, reduce overreliance on chemical pesticides, safeguard agroecosystems, and enhance crop yield and quality. This review explores the different classes of biopesticides (including biochemical, microbial, and plant-incorporated protectants), their modes of action, and their potential to enhance IPM strategies. The prospects of integrating emerging biopesticide technologies, such as nano-biopesticides and RNA-based biopesticides, into the existing IPM programs are also discussed.

19 June 2025 in Insects
Verified
Journal Article
Open access
PDF file
GKGrace Kinyanjui
Grace Kinyanjui
Kahsay Tadesse MawchaKahsay Tadesse Mawcha
Kahsay Tadesse Mawcha
Lawrence Nkosikhona MalingaLawrence Nkosikhona Malinga
Lawrence Nkosikhona Malinga
KSKaitlyn Soobramoney
Kaitlyn Soobramoney
PNPhophi Dzivhuluwani Nethononda
Phophi Dzivhuluwani Nethononda
Dennis ObonyoDennis Obonyo
Dennis Obonyo
The African armyworm Spodoptera exempta (Lepidoptera: Noctuidae) is a significant pest that affects cereal crops and pasture grasses in sub-Saharan Africa. This migratory pest causes extensive defoliation, which can result in significant yield losses, particularly in maize. This review focuses on the recent outbreaks of the African armyworm and identifies key factors contributing to its success across sub-Saharan Africa. Understanding these factors is essential for developing effective and sustainable pest management strategies. This review emphasizes the importance of innovative technologies and data-driven approaches in managing pest outbreaks and underscores the need to implement technology-enabled integrated pest management (IPM) strategies to control the African armyworm effectively.

19 June 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
KMKahsay Tadesse Mawcha
Kahsay Tadesse Mawcha
AHAthanase Hategekimana
Athanase Hategekimana
KJKajuga Nsamira Joelle
Kajuga Nsamira Joelle
Dennis ObonyoDennis Obonyo
Dennis Obonyo
WYWenxiang Yang
Wenxiang Yang
Millipedes are soil-dwelling organisms that play a crucial role in nutrient cycling and soil health. They can increase the availability of nitrogen and phosphorus, as well as accelerate the decomposition of organic matter in the soil. However, millipedes can also cause significant damage to crops, leading to yield losses and indirect effects on soil quality and plant health. Effective management of millipedes may involve a combination of cultural and chemical control methods tailored to specific crops and environmental conditions. Integrated pest management strategies, emphasizing a holistic, ecosystem-based approach, may be particularly effective for managing millipede populations while minimizing negative impacts on the environment. Monitoring is also essential for identifying areas of high millipede activity and targeting control measures accordingly. This review provides recent research progress on the biology, ecology, and agricultural pest status of millipedes, as well as IPM strategies to control their infestation in agricultural crops and beyond.

27 March 2018 in Insects
Verified
Journal Article
Open access
PDF file
Dennis ObonyoDennis Obonyo
Dennis Obonyo
JSJosephine M. Songa
Josephine M. Songa
Gabor L LöveiGabor L Lövei
Gabor L Lövei
Environmental stress can affect trait size and cause an increase in the fluctuating asymmetry (FA) of bilateral morphological traits in many animals. For insect parasitoids, feeding of hosts on transgenic maize, expressing a Bacillus thuringiensis toxin gene is a potential environmental stressor. We compared the size of antennae, forewings, and tibia, as well as their FA values, in two parasitoids developed on two East African host species feeding on non-transgenic vs. transgenic maize. The two lepidopteran stem-borer hosts were the native Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and a recent invader, Chilo partellus Swinhoe (Lepidoptera: Crambidae). The two braconid parasitoids were the native, gregarious larval endoparasitoid Cotesia sesamiae and the recently introduced Cotesia flavipes. Both parasitoids attacked both hosts, creating evolutionarily old vs. novel interactions. Transient feeding of hosts on transgenic maize had various effects on FA, depending on trait as well as the host and parasitoid species. These effects were usually stronger in evolutionarily novel host–parasitoid associations than in the older, native ones. These parameters have capacity to more sensitively indicate the effects of potential stressors and merit further consideration.