insects
Article
Distribution and Molecular Diversity of Whitefly Species
Colonizing Cassava in Kenya
Florence M. Munguti
1,2,
* , Dora C. Kilalo
1
, Evans N. Nyaboga
3
, Everlyne N. Wosula
4
, Isaac Macharia
2
and Agnes W. Mwango’mbe
1
Citation: Munguti, F.M.; Kilalo, D.C.;
Nyaboga, E.N.; Wosula, E.N.;
Macharia, I.; Mwango’mbe, A.W.
Distribution and Molecular Diversity
of Whitefly Species Colonizing
Cassava in Kenya. Insects 2021, 12,
875. https://doi.org/10.3390/
insects12100875
Academic Editor: Dorith Rotenberg
Received: 30 July 2021
Accepted: 4 September 2021
Published: 27 September 2021
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1
Department of Plant Science and Crop Protection, University Nairobi, Kangemi,
Nairobi P.O. Box 29053-00625, Kenya; dchao@uonbi.ac.ke (D.C.K.); wakesho123@gmail.com (A.W.M.)
2
Kenya Plant Health Inspectorate Service, GPO, Nairobi P.O. Box 49592-00100, Kenya;
macharia.isaac@kephis.org
3
Department of Biochemistry, University Nairobi, GPO, Nairobi P.O. Box 30197-00100, Kenya;
nyaboga@uonbi.ac.ke
4
International Institute of Tropical Agriculture, Dar es Salaam P.O. Box 34441, Tanzania; E.Wosula@cgiar.org
* Correspondence: fmunguti@kephis.org
Simple Summary: The whitefly, Bemisia tabaci (Gennadium, Hemiptera) is a crop pest and plant-
virus vector known to transmit more than 300 plant viruses. Among other plant viruses, the vector
transmits viruses that cause the two major devastating viral diseases of cassava in sub-Saharan
Africa namely cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). In order
to achieve effective implementation of whitefly management programs including prevention of
spread of the species, accurate species identification is vital. Morphological identification approaches
toward whitefly species limits the capacity to accurately identify new species, especially the presence
of cryptic species such as the numerous B. tabaci genetic groups. Using the mitochondrial DNA
cytochrome oxidase 1 (mtCO1) sequences, four distinct whitefly species namely Bemisia tabaci,
Bemisia afer, Aleurodicus dispersus and Paraleyrodes bondari were identified in samples collected from
major cassava growing regions in Kenya. The study presents the first report of P. bondari (Bondar’s
nesting whitefly) on cassava in Kenya. We found three B. tabaci genetic groups of SSA1, SSA2 and
Indian Ocean (IO) putative species colonizing cassava in Kenya. The information is useful to inform
better management strategies of the whitefly vectors to reduce the impact of cassava viral diseases,
which continue to be a threat to food security in major cassava growing regions.
Abstract: The whitefly, Bemisia tabaci (Gennadium, Hemiptera) has been reported to transmit viruses
that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) in many parts
of sub-Saharan Africa (SSA). Currently, there is limited information on the distribution, species
and haplotype composition of the whitefly populations colonizing cassava in Kenya. A study
was conducted in the major cassava growing regions of Kenya to address this gap. Analyses of
mitochondrial DNA cytochrome oxidase 1 (mtCO1) sequences revealed the presence of four distinct
whitefly species: Bemisia tabaci, Bemisia afer, Aleurodicus dispersus and Paraleyrodes bondari in Kenya.
The B. tabaci haplotypes were further resolved into SSA1, SSA2 and Indian Ocean (IO) putative species.
The SSA1 population had three haplogroups of SSA1-SG1, SSA-SG2 and SSA1-SG3. Application
of KASP genotyping grouped the Bemisia tabaci into two haplogroups namely sub-Saharan Africa
East and Southern Africa (SSA-ESA) and sub-Saharan Africa East and Central Africa (SSA-ECA).
The study presents the first report of P. bondari (Bondar’s nesting whitefly) on cassava in Kenya.
Bemisia tabaci was widely distributed in all the major cassava growing regions in Kenya. The increased
detection of different whitefly species on cassava and genetically diverse B. tabaci mitotypes indicates
a significant influence on the dynamics of cassava virus epidemics in the field. The study highlights
the need for continuous monitoring of invasive whitefly species population on cassava for timely
application of management practices to reduce the impact of cassava viral diseases and prevent
potential yield losses.
Keywords: Bemisia tabaci; mtCOI gene; P. bondari; KASP genotyping; haplotype
Insects 2021, 12, 875. https://doi.org/10.3390/insects12100875 https://www.mdpi.com/journal/insects