Journal of Economic Entomology (2019) 112, 2389-2397

B.A. Rasowo, F.M. Khamis, S.A. Mohamed, I.J. Ajene, O.F. Aidoo, L. Ombura, M. Sétamou, S. Ekesi and C. Borgemeister (2019)
African citrus greening disease in East Africa: Incidence, severity, and distribution patterns
Journal of Economic Entomology 112 (5), 2389-2397
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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mamoudou Sétamou, Sunday Ekesi, Christian Borgemeister

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Trioza erytreae		Kenya
	Diaphorina citri		Kenya
	Liberibacter africanus		Kenya