During the 1990s, an epidemic of an unusually severe form of cassava mosaic virus disease (CMD) has expanded to cover virtually all of Uganda, and substantial areas in the neighbouring countries of Kenya, Tanzania, Sudan and the Democratic Republic of Congo. Losses in the generally sensitive loca...
Legg, J.P.
,
[Emergence, spread and strategies for controlling the pandemic of cassava mosaic virus disease in east and central Africa]
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Emergence, spread and strategies for controlling the pandemic of cassava mosaic virus disease in east and central Africa
Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) is the vector of cassava mosaic geminiviruses that cause cassava mosaic disease (CMD), which in turn causes devastating yield losses. Surveys were conducted from October 2000 to November 2001 in four agro-ecologies in Uganda to enhance the underst...
Otim, M.
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Legg, J.P.
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Kyamanywa, S.
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Polaszek, A.
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Gerling, D.
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[Occurrence and activity of Bemisia tabaci parasitoids on cassava in different agro-ecologies in Uganda]
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Occurrence and activity of Bemisia tabaci parasitoids on cassava in different agro-ecologies in Uganda
A survey in Senegal and Guinea Conakry established the presence and incidence of cassava mosaic virus disease (CMD) in both countries. CMD occurred in all the fields surveyed, although its incidence was higher in Senegal (83%) than in Guinea (64%). Populations of the whitefly vector, Bemisia taba...
Okao‐Okuja, G.
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Legg, J.P.
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Traoré, L.
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Jorge, M.A.B.
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[Viruses associated with cassava mosaic disease in Senegal and Guinea Conakry]
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Viruses associated with cassava mosaic disease in Senegal and Guinea Conakry
The extent of genetic variability and host-plant distribution of Bemisia tabaci (Gennadius) genotypes colonising cultivated and uncultivated plant species occurring adjacent to cassava fields in selected cassava-producing areas of Uganda in 2003/04 were investigated using the mitochondrial cytoch...
Sseruwagi, P.
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Legg, J.P.
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Maruthi, M.
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Colvin, J.
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Rey, M.
,
Brown, J.
,
[Genetic diversity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations and presence of the B biotype and a nonB biotype that can induce silverleaf symptoms in quash, in Uganda]
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Genetic diversity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations and presence of the B biotype and a nonB biotype that can induce silverleaf symptoms in quash, in Uganda
The ecology of the Bemisia tabaci/cassava/African cassava mosaic virus (ACMV) pathosystem is reviewed briefly with special attention given to the parameters affecting the pattern of population development of B. tabaci. Significant gaps in our understanding of this system remain, particularly conc...
Legg, J.P.
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[Bemisia tabaci: the whitefly vector of cassava mosaic geminiviruses in Africa: an ecological perspective]
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Bemisia tabaci: the whitefly vector of cassava mosaic geminiviruses in Africa: an ecological perspective
Parasitism rates of Bemisia tabaci(Gennadius) and searching and oviposition behaviours of its parasitoid Eretmocerus mundus Mercet were compared on two cassava varieties: a glabrous variety, Nase 4 and a hirsute variety, MM970245 withc.88 leaf hairscm2. Parasitism was assessed after potted plants...
Otim, M.
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Kyalo, G.
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Kyamanywa, S.
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Asiimwe, P.
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Legg, J.P.
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Guershon, M
,
Gerling, D.
,
[Parasitism of Bemisia tabaci (Homoptera: aleyrodidae) by Eretmocerus mundus (Hymenoptera: aphelinidae) on cassava]
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Parasitism of Bemisia tabaci (Homoptera: aleyrodidae) by Eretmocerus mundus (Hymenoptera: aphelinidae) on cassava
Bemisia tabaci threatens production of cassava in Africa through vectoring viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). B. tabaci sampled from cassava in eight countries in Africa were genotyped using NextRAD sequencing, and their phylogeny and populati...
Wosula, Everlyne N.
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Chen, W.
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Fei, Z.
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Legg, J.P.
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[Unravelling the genetic diversity among cassava Bemisia tabaci whiteflies using NextRAD Sequencing]
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Unravelling the genetic diversity among cassava Bemisia tabaci whiteflies using NextRAD Sequencing
The sweetpotato whitefly, Bemisia tabaci (Gennadius) is the vector of the cassava mosaic geminiviruses (CMGs) that cause cassava mosaic disease (CMD). Synergistic interactions between B. tabaci and CMGs have been hypothesized as a cause of whitefly “super-abundance,” which has been a key factor b...
A survey was carried out of African cassava mosaic geminivirus and cassava brown streak virus diseases (ACMD and CBSD) in Tanzania. ACMD occurred throughout the country at low to moderate incidences in the fifteen different regions surveyed (1- 64%). The incidence was generally higher along the c...
Cassava mosaic disease and cassava brown streak disease are caused by viruses transmitted by Bemisia tabaci and affect approximately half of all cassava plants in Africa, resulting in annual production losses of more than $US 1 billion. A historical and current bias towards virus rather than vect...
Legg, J.P.
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Shirima, R.R.
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Tajebe, L.
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Guastella, D.
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Boniface, S.
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Jeremiah, S.
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Nsami, E.
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Chikoti, Patrick Chiza
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Rapisarda, C.
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[Biology and management of Bemisia whitefly vectors of cassava virus pandemics in Africa]
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Biology and management of Bemisia whitefly vectors of cassava virus pandemics in Africa