1
|
Ajene IJ, Heya H, Khamis FM. Evaluating the mitochondrial genomic diversity, global distribution and niche overlap of two invasive Phthorimaea species. Heliyon 2024; 10:e29010. [PMID: 38617910 PMCID: PMC11015427 DOI: 10.1016/j.heliyon.2024.e29010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 03/21/2024] [Accepted: 03/28/2024] [Indexed: 04/16/2024] Open
Abstract
This study sought to evaluate the genetic diversity of two invasive Phthorimaea species (Phthorimaea operculella Zeller and Phthorimaea absoluta Meyrick), and identify potential niche overlap of both species. The complete mitogenomes of P. operculella and P. absoluta were sequenced and compared. Furthermore, the diversity within the family Gelechiidae was assessed. Subsequently, two species distribution models (MaxEnt and BIOCLIM) were used to identify niche overlaps of both species globally. The complete mitogenomes of both species were similar in size and structure, with a pairwise identity of 92.3%. The models showed a niche overlap of both species and revealed areas of marginal to high suitability for both pests in countries where they have not been reported. Therefore, these results present a compelling case for a deeper genetic and ecological investigation of the Gelechiidae family for taxonomic harmonization, an early warning for surveillance, stricter phytosanitary considerations and preventive management against the spread of the pests.
Collapse
Affiliation(s)
- Inusa Jacob Ajene
- International Center of Insect Physiology and Ecology, Nairobi, Kenya
| | - Helen Heya
- Kenya Plant Health Inspectorate Service, Nairobi, Kenya
| | | |
Collapse
|
2
|
Maingi FM, Akutse KS, Ajene IJ, Omolo KM, Khamis FM. Immunological responses and gut microbial shifts in Phthorimaea absoluta exposed to Metarhizium anisopliae isolates under different temperature regimes. Front Microbiol 2023; 14:1258662. [PMID: 38029135 PMCID: PMC10666277 DOI: 10.3389/fmicb.2023.1258662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
The invasive tomato leaf miner, Phthorimaea absoluta, is conventionally controlled through chemical insecticides. However, the rise of insecticide resistance has necessitated sustainable and eco-friendly alternatives. Entomopathogenic fungi (EPF) have shown potential due to their ability to overcome resistance and have minimal impact on non-target organisms. Despite this potential, the precise physiological mechanisms by which EPF acts on insect pests remain poorly understood. To attain a comprehensive understanding of the complex physiological processes that drive the successful control of P. absoluta adults through EPF, we investigated the impacts of different Metarhizium anisopliae isolates (ICIPE 665, ICIPE 20, ICIPE 18) on the pest's survival, cellular immune responses, and gut microbiota under varying temperatures. The study unveiled that ICIPE 18 caused the highest mortality rate among P. absoluta moths, while ICIPE 20 exhibited the highest significant reduction in total hemocyte counts after 10 days at 25°C. Moreover, both isolates elicited notable shifts in P. absoluta's gut microbiota. Our findings revealed that ICIPE 18 and ICIPE 20 compromised the pest's defense and physiological functions, demonstrating their potential as biocontrol agents against P. absoluta in tomato production systems.
Collapse
Affiliation(s)
- Felix Muendo Maingi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Komivi Senyo Akutse
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Unit for Environment Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Inusa Jacob Ajene
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Kevin Mbogo Omolo
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | | |
Collapse
|
3
|
Ong'onge MA, Ajene IJ, Runo S, Sokame BM, Khamis FM. Population dynamics and insecticide resistance in Tuta absoluta (Lepidoptera: Gelechiidae), an invasive pest on tomato in Kenya. Heliyon 2023; 9:e21465. [PMID: 38027621 PMCID: PMC10660591 DOI: 10.1016/j.heliyon.2023.e21465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 10/05/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023] Open
Abstract
Tuta absoluta feeds on solanaceous plants with preference on tomato. Management of the pest is mostly with chemical insecticides. This study identified insecticide resistant populations and predicted resistance to insecticides. Insecticide resistance development was modelled using system thinking, and system dynamics approaches. The model showed the pest resistance development is alarming with an exponential increase of the resistance strength mostly in recent years. Furthermore, we used seven insecticide-resistance gene markers to resolve the population structure and genetic differentiation of insecticide-resistant populations in Kenya. The genes for resistance (knockdown resistance (kdr) mutations, acetylcholinesterase (AChE) and voltage gated sodium channel (para)) were detected in all populations. Population structure analyses separated T. absoluta populations into three genetic clusters with resistant genes that are interconnected. A better insight on the population dynamics and the genetic structure T. absoluta resistant genes in Kenya will help estimate resistance strength and determine the most effective pest control strategies.
Collapse
Affiliation(s)
- Maureen Adhiambo Ong'onge
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - Inusa Jacob Ajene
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Steven Runo
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi, Kenya
| | | | | |
Collapse
|
4
|
Ajene IJ, Khamis FM, van Asch B, Pietersen G, Seid N, Wairimu AW, Ombura FL, Akutse KS, Sétamou M, Subramanian S, Mohammed S, Ekesi S. Genetic diversity of Diaphorina citri (Hemiptera: Liviidae) unravels phylogeographic structure and invasion history of eastern African populations. Ecol Evol 2022; 12:e9090. [PMID: 35866018 PMCID: PMC9289372 DOI: 10.1002/ece3.9090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/06/2022] [Accepted: 06/17/2022] [Indexed: 01/18/2023] Open
Abstract
The Asian citrus psyllid (Diaphorina citri Kuwayama) is a key pest of Citrus sp. worldwide, as it acts as a vector for Candidatus Liberibacter asiaticus, the bacterial pathogen that causes citrus Huanglongbing. Diaphorina citri has been reported in Kenya, Tanzania, and more recently in Ethiopia. This study assessed the genetic diversity and phylogeographic structure of the pest to gain insights into the potential sources of its introduction into Africa. Population structure and differentiation of D. citri populations from China, Ethiopia, Kenya, Tanzania, and the USA were assessed using 10 microsatellite loci. Additionally, five new complete mitogenomes of D. citri collected in China, Ethiopia, Kenya, Tanzania, and the USA were analyzed in the context of publicly available sequences. Genotype data grouped the D. citri populations from Kenya and Tanzania in one cluster, and those from Ethiopia formed a separate cluster. The two genetic clusters inferred from genotype data were congruent with mitochondrial sequence data. The mitogenomes from Kenya/Tanzania/China had 99.0% similarity, and the Ethiopia/USA had 99.9% similarity. In conclusion, D. citri populations in eastern Africa have different sources, as the Kenyan and Tanzanian populations probably originated from southeastern Asia, while the Ethiopian population most probably originated from the Americas.
Collapse
Affiliation(s)
- Inusa Jacob Ajene
- Department of Crop Protection Faculty of Agriculture Ahmadu Bello University Zaria Nigeria.,International Center of Insect Physiology and Ecology Nairobi Kenya.,Department of Genetics Stellenbosch University Stellenbosch South Africa
| | | | - Barbara van Asch
- Department of Genetics Stellenbosch University Stellenbosch South Africa
| | - Gerhard Pietersen
- Department of Genetics Stellenbosch University Stellenbosch South Africa
| | - Nurhussen Seid
- Ethiopian Institute of Agricultural Research Addis Ababa Ethiopia
| | | | | | | | | | | | - Samira Mohammed
- International Center of Insect Physiology and Ecology Nairobi Kenya
| | - Sunday Ekesi
- International Center of Insect Physiology and Ecology Nairobi Kenya
| |
Collapse
|
5
|
Ajene IJ, Khamis F, van Asch B, Pietersen G, Rasowo BA, Ekesi S, Mohammed S. Habitat suitability and distribution potential of Liberibacter species (
“Candidatus
Liberibacter asiaticus
”
and
“Candidatus
Liberibacter africanus
”
) associated with citrus greening disease. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Inusa Jacob Ajene
- International Center of Insect Physiology and Ecology Nairobi Kenya
- Department of Genetics Stellenbosch University Stellenbosch South Africa
- Department of Crop Protection Faculty of Agriculture Ahmadu Bello University Zaria Nigeria
| | - Fathiya Khamis
- International Center of Insect Physiology and Ecology Nairobi Kenya
| | - Barbara van Asch
- Department of Genetics Stellenbosch University Stellenbosch South Africa
| | - Gerhard Pietersen
- Department of Genetics Stellenbosch University Stellenbosch South Africa
| | | | - Sunday Ekesi
- International Center of Insect Physiology and Ecology Nairobi Kenya
| | - Samira Mohammed
- International Center of Insect Physiology and Ecology Nairobi Kenya
| |
Collapse
|
6
|
Rasowo BA, Khamis FM, Mohamed SA, Ajene IJ, Aidoo OF, Ombura L, Sétamou M, Ekesi S, Borgemeister C. African Citrus Greening Disease in East Africa: Incidence, Severity, and Distribution Patterns. J Econ Entomol 2019; 112:2389-2397. [PMID: 31219591 DOI: 10.1093/jee/toz167] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Indexed: 06/09/2023]
Abstract
African citrus greening disease (ACGD) is considered as one of the major diseases of citrus threatening citrus production in East Africa. Our study aimed for the first time to assess the incidence, severity, and distribution patterns of ACGD in Kenya and Tanzania. In total, 105 citrus orchards were assessed in 13 regions representing low, mid, and high altitude areas. In each backyard and orchard, trees were randomly selected and rated for visual ACGD symptoms; then leaves and insect samples collected for analysis of 'Candidatus Liberibacter africanus' (CLaf), the presumptive causal agent of ACGD. Endpoint PCR, sequencing, and molecular phylogenetic tools were employed to confirm the identity of potential circulating pathogens. Incidence and severity of ACGD varied significantly among the different regions. Both Trioza erytreae (Del Guerico) (Hemiptera: Triozidae) and the invasive Asian citrus psyllid vector Diaphorina citri (Kuwayama) (Hemiptera: Liviidae) were found to co-occur in upper and lower midland regions. Molecular characterization identified 'Candidatus Liberibacter africanus spp. Clausenae' (CLafCl) as the main causal agent of ACGD in most of the citrus plants and insect samples. No instances of Candidatus Liberibacter asiaticus infection were found. These findings provide valuable insights into understanding and management of ACGD by employing stringent and early disease detection tools to curb the spread of the disease.
Collapse
Affiliation(s)
- B A Rasowo
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
- Center for Development Research (ZEF), University of Bonn, Bonn, Germany
| | - F M Khamis
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
| | - S A Mohamed
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
| | - I J Ajene
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
| | - O F Aidoo
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
- Center for Development Research (ZEF), University of Bonn, Bonn, Germany
| | - L Ombura
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
| | - M Sétamou
- Texas A&M University, Kingsville Citrus Centre, Weslaco, TX
| | - S Ekesi
- International Centre of Insect Physiology and Ecology (icipe), GPO, Nairobi, Kenya
| | - C Borgemeister
- Center for Development Research (ZEF), University of Bonn, Bonn, Germany
| |
Collapse
|