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    Biological control of the cassava mealybug Phenacoccus manihoti (Hom., Pseudococcidae) by Epidinocarsis lopezi (De Santis) (Hym., Encyrtidae) in West Africa, as influenced by climate and soil

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    Journal Article (718.4Kb)
    Date
    1990
    Author
    Neuenschwander, P.
    Hammond, W.
    Ajuonu, O.
    Gado, A.
    Echendu, N.
    Bokonon-Ganta, A.
    Allomasso, R.
    Okon, I.
    Type
    Journal Article
    Review Status
    Peer Review
    Target Audience
    Scientists
    Metadata
    Show full item record
    Abstract/Description
    Population data concerning the cassava mealybug (CM) Phenacoccus manihoti Matile-Ferrero, the introduced parasitoid Epidinocarsis lopezi (De Santis), and indigenous antagonists were collected, together with ecological and plant growth variables, during a survey of 414 fields covering all ecological zones of Nigeria and Benin, for evaluation in multiple regression analyses. The choice of fields was unbiased, and insect populations were estimated from large random samples. Seven years after the first release of E. lopezi, the entire area, with the exception of an isolated CM population near Lake Chad, had been colonized by the parasitoid. Within the area of distribution of E. lopezi, average CM populations were very low (1.6 CM per shoot tip), highest densities being found in the forest transition zone. The mean tip damage score on a scale from 1 to 5 was only 1.2. Only 3.2% of all tips were strongly stunted, the same percentage had more than 10 CM, and no tip had over 1000 CM. However, significant tip damage persisted on the 4.8% of fileds with unmulched, sandy soils in the forest zone. In these fields, 3.3 times fewer CM were needed to cause heavy stunting than on less stressed plants on soils with mulch, or clay, or less rain. This deleterious effect of leaching and lack of crop rotation was alleviated completely in the fields which had a small amount of mulch. Thus, agronomic factors, mediated through the condition of the plant, influenced biological control.
    https://dx.doi.org/10.1016/0167-8809(90)90122-T
    Multi standard citation
    Permanent link to this item
    https://hdl.handle.net/20.500.12478/7556
    IITA Authors ORCID
    Peter NEUENSCHWANDERhttps://orcid.org/0000-0003-0580-0376
    Digital Object Identifier (DOI)
    https://dx.doi.org/10.1016/0167-8809(90)90122-T
    Research Themes
    Plant Production and Health
    IITA Subjects
    Cassava; Disease Control; Pests of Plants; Plant Breeding; Plant Diseases; Plant Health; Plant Production
    Agrovoc Terms
    Cassava; Mealybugs; Biological Control; Phenacoccus Manihoti; Parasitoids
    Regions
    Africa; West Africa
    Countries
    Benin (Dahomey); Nigeria
    Hubs
    Headquarters and Western Africa Hub
    Journals
    Agriculture, Ecosystems and Environment
    Collections
    • Journal and Journal Articles5286
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