1
|
Aidoo OF, Ablormeti FK, Ninsin KD, Antwi-Agyakwa AK, Osei-Owusu J, Heve WK, Dofuor AK, Soto YL, Edusei G, Osabutey AF, Sossah FL, Aryee CO, Alabi OJ, Sétamou M. First report on the presence of huanglongbing vectors (Diaphorina citri and Trioza erytreae) in Ghana. Sci Rep 2023; 13:11366. [PMID: 37443168 PMCID: PMC10344884 DOI: 10.1038/s41598-023-37625-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/24/2023] [Indexed: 07/15/2023] Open
Abstract
As significant threats to global citrus production, Diaphorina citri (Kuwayama; Hemiptera: Psyllidae) and Trioza erytreae (Del Guercio; Hemiptera: Triozidae) have caused considerable losses to citrus trees globally. Diaphorina citri vectors "Candidatus Liberibacter asiaticus" and "Ca. L. americanus", whereas T. erytreae transmits "Ca. L. africanus" and "Ca. L. asiaticus", the pathogens responsible for citrus greening disease or Huanglongbing (HLB). Though HLB is a destructive disease of citrus wherever it occurs, information on the occurrence and geographical distribution of its vectors in Africa is limited. In recent surveys to determine if HLB vectors are present in Ghana, we observed eggs, nymphs, and adults of insects suspected to be D. citri and T. erytreae. Using morphological traits and DNA analyses, the identity of the suspected insects was confirmed to be D. citri and T. erytreae. Individuals of D. citri and T. erytreae were examined using qPCR for CLaf, CLam, and CLas, but none of them tested positive for any of the Liberibacter species. Herein we report, for the first time, the presence of D. citri and T. erytreae in Ghana (West Africa). We discuss the implications of this new threat to the citrus industry to formulate appropriate management strategies.
Collapse
Affiliation(s)
- Owusu F Aidoo
- Department of Biological Sciences, University of Environment and Sustainable Development, PMB, Somanya, E/R, Ghana.
| | - Fred K Ablormeti
- Council for Scientific Industrial Research, Oil Palm Research Institute, Coconut Research Programme, P. O. Box 245, Sekondi, Ghana
| | - Kodwo D Ninsin
- Department of Biological Sciences, University of Environment and Sustainable Development, PMB, Somanya, E/R, Ghana
| | | | - Jonathan Osei-Owusu
- Department of Physical and Mathematical Sciences, University of Environment and Sustainable Development, Somanya, Ghana
| | - William K Heve
- Department of Biological Sciences, University of Environment and Sustainable Development, PMB, Somanya, E/R, Ghana
| | - Aboagye K Dofuor
- Department of Biological Sciences, University of Environment and Sustainable Development, PMB, Somanya, E/R, Ghana
| | - Yovanna L Soto
- Texas A&M University-Kingsville Citrus Center, Weslaco, 78599, USA
| | - George Edusei
- Department of Physical and Mathematical Sciences, University of Environment and Sustainable Development, Somanya, Ghana
| | | | - Frederick L Sossah
- Council for Scientific Industrial Research, Oil Palm Research Institute, Coconut Research Programme, P. O. Box 245, Sekondi, Ghana
| | | | - Olufemi J Alabi
- Department of Plant Pathology and Microbiology, Texas A&M AgriLife Research and Extension Center, Weslaco, TX, 78596, USA
| | - Mamoudou Sétamou
- Texas A&M University-Kingsville Citrus Center, Weslaco, 78599, USA.
| |
Collapse
|
2
|
Parajuli S, Beattie GAC, Holford P, Yang C, Cen Y. Susceptibility of Diaphorina citri to Irradiation with UV-A and UV-B and the Applicability of the Bunsen-Roscoe Reciprocity Law. INSECTS 2023; 14:insects14050445. [PMID: 37233073 DOI: 10.3390/insects14050445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/01/2023] [Accepted: 05/01/2023] [Indexed: 05/27/2023]
Abstract
Populations of Diaphorina citri decline with elevation and, in a study in Bhutan, were rarely found above 1200 m ASL. The impact of ultraviolet (UV) radiation, particularly UV-B, on immature stages of the psyllid was proposed as limiting factor. As no studies have been undertaken on the influences of UV radiation on the development of D. citri, we examined the effects of UV-A and UV-B on different stadia of the psyllid. In addition, compliance with the Bunsen-Roscoe reciprocity law was examined. Irradiation with UV-A marginally reduced egg hatch and the survival times of emerging nymphs. Early instar nymphs were little affected by this waveband, but the survival of adults was reduced at the higher doses used. With UV-B, egg hatch and the survival times of early and late instar nymphs declined in proportion to UV-B dose. A dose of 57.6 kJ m-2 d-1 reduced the survival time of only adult females. Female fecundity was reduced at high UV-A and UV-B doses but increased at low doses. The Bunsen-Roscoe law held true for eggs and early instar nymphs for different durations and irradiances of UV-B. Eggs and nymphs had ED50 values for UV-B lower than the daily fluxes of this wavelength experienced worldwide. Thus, UV-B could be a factor causing the psyllid to be scarce at high elevations.
Collapse
Affiliation(s)
- Sabina Parajuli
- Citrus Huanglongbing Research Laboratory/Key Laboratory of Bio-Pesticide Innovation and Application/National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou 510642, China
| | | | - Paul Holford
- School of Science, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Chuping Yang
- College of Electronic Engineering, South China Agricultural University, Guangzhou 510642, China
| | - Yijing Cen
- Citrus Huanglongbing Research Laboratory/Key Laboratory of Bio-Pesticide Innovation and Application/National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou 510642, China
| |
Collapse
|
3
|
Hunter WB, Wintermantel WM. Optimizing Efficient RNAi-Mediated Control of Hemipteran Pests (Psyllids, Leafhoppers, Whitefly): Modified Pyrimidines in dsRNA Triggers. PLANTS 2021; 10:plants10091782. [PMID: 34579315 PMCID: PMC8472347 DOI: 10.3390/plants10091782] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 01/09/2023]
Abstract
The advantages from exogenously applied RNAi biopesticides have yet to be realized in through commercialization due to inconsistent activity of the dsRNA trigger, and the activity level of RNAi suppression. This has prompted research on improving delivery methods for applying exogenous dsRNA into plants and insects for the management of pests and pathogens. Another aspect to improve RNAi activity is the incorporation of modified 2′-F pyrimidine nucleotides into the dsRNA trigger. Modified dsRNA incorporating 32–55% of the 2′-F- nucleotides produced improved RNAi activity that increased insect mortality by 12–35% greater than non-modified dsRNA triggers of the same sequence. These results were repeatable across multiple Hemiptera: the Asian citrus psyllid (Diaphorina citri, Liviidae); whitefly (Bemisia tabaci, Aleyroididae); and the glassy-winged sharpshooter (Homalodisca vitripennis, Cicadellidae). Studies using siRNA with modified 2′-F- pyrimidines in mammalian cells show they improved resistance to degradation from nucleases, plus result in greater RNAi activity, due to increase concentrations and improved binding affinity to the mRNA target. Successful RNAi biopesticides of the future will be able to increase RNAi repeatability in the field, by incorporating modifications of the dsRNA, such as 2′-F- pyrimidines, that will improve delivery after applied to fruit trees or crop plants, with increased activity after ingestion by insects. Costs of RNA modification have decreased significantly over the past few years such that biopesticides can now compete on pricing with commercial chemical products.
Collapse
Affiliation(s)
- Wayne Brian Hunter
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture, Agriculture Research Service, Subtropical Insects Res., Fort Pierce, FL 34945, USA
- Correspondence:
| | - William M. Wintermantel
- U.S. Department of Agriculture, Agriculture Research Service, Crop Improvement and Protection Research, Salinas, CA 93905, USA;
| |
Collapse
|