ausblenden:
Schlagwörter:
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Zusammenfassung:
Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest species complex that
causes widespread damage to cassava, a staple food crop for millions of households in
East Africa. Species in the complex cause direct feeding damage to cassava and are the
vectors of multiple plant viruses. Whilst significant work has gone into developing
virus-resistant cassava cultivars, there has been little research effort aimed at understanding
the ecology of these insect vectors. Here we assess critically the knowledge
base relating to factors that may lead to high population densities of sub-Saharan
African (SSA) B. tabaci species in cassava production landscapes of East Africa. We
focus first on empirical studies that have examined biotic or abiotic factors that may
lead to high populations.We then identify knowledge gaps that need to be filled to deliver
sustainable management solutions.We found that whilst many hypotheses have
been put forward to explain the increases in abundancewitnessed since the early 1990s,
there are little published data and these tend to have been collected in a piecemeal manner.
The most critical knowledge gaps identified were: (i) understanding how cassava
cultivars and alternative host plants impact population dynamics and natural enemies;
(ii) the impact of natural enemies in terms of reducing the frequency of outbreaks and
(iii) the use and management of insecticides to delay the development of resistance. In
addition, there are several fundamental methodologies that need to be developed and deployed in East Africa to address some of the more challenging knowledge gaps.
