• Contact Us
    • Send Feedback
    • Login
    View Item 
    •   Home
    • Journal and Journal Articles
    • Journal and Journal Articles
    • View Item
    •   Home
    • Journal and Journal Articles
    • Journal and Journal Articles
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    Whole Repository
    CollectionsIssue DateRegionCountryHubAffiliationAuthorsTitlesSubject
    This Sub-collection
    Issue DateRegionCountryHubAffiliationAuthorsTitlesSubject

    My Account

    Login

    Welcome to the International Institute of Tropical Agriculture Research Repository

    What would you like to view today?

    Natural enemy activity following the introduction of Epidinocarsis lopezi (Hymenoptera: encyrtidae) against the cassava mealybug, Phenacoccus manihoti (Homoptera: psudococcidae), in southwestern Nigeria

    Thumbnail
    View/Open
    S88ArtNeuenschwanderNaturalInthomNodev.PDF (3.719Mb)
    Date
    1988
    Author
    Neuenschwander, P.
    Hammond, W.N.O.
    Type
    Journal Article
    Target Audience
    Scientists
    Metadata
    Show full item record
    Abstract/Description
    The effectiveness of the exotic South American hymenopterous parasitoid Epidinocarsis lopezi (De Santis) in controlling the cassava mealybug (CM), Phenacoccus manihoti Matile-Ferrero, in southwestern Nigeria, was assessed using emergence samples. Ten infested cassava tips were collected from each of 679 fields during four surveys over an area of 200,000 km2 in the 2 yr following establishment of the parasitoid. These samples were used to determine frequency and abundance of this and other insects associated with the CM. Survey results suggest that CM infestation levels as measured by frequency of plants showing CM damage symptoms declined as a result of the parasitoid's activity from 88% at the end of the first dry season (March 1983) to 23% in the same period the following year. E. lopezi numbers per field also declined during the same period, but parasitoid densities per infested cassava tip in both years remained the same. A sharp fall in numbers of indigenous polyphagous coccinellids on cassava, particularly of Hyperaspis spp. and to a lesser extent of Exochomus sp., was also associated with decline in CM infestation levels. By contrast, the infested tip densities of the cecidomyiid Dicrodiplosis manihoti Harris, which is specific on CM, were not affected. Other indigenous primary parasitoids of the genus Anagyrus were rare. Ten species of native hyperparasitoids were common from E. lopezi; most common were Prochiloneurus spp. and Chartocerus spp. As E. lopezi densities declined, percent hyperparasitism dropped significantly from 43.8% in March 1983 to 30.7% in March 1984, and from 35.7% in December 1983 to 17.5% in December 1984. In the last two surveys, CM densities, as determined from dissected cassava tips, were low throughout southwestern Nigeria. It is concluded that E. lopezi is responsible for declines in CM densities and damage symptoms, for reduction of coccinellid abundance via competition for a common food source, and that hyperparasitism does not prevent E. lopezi from being an efficient parasitoid.
    https://doi.org/10.1093/ee/17.5.894
    Multi standard citation
    Permanent link to this item
    https://hdl.handle.net/20.500.12478/1744
    Digital Object Identifier (DOI)
    https://doi.org/10.1093/ee/17.5.894
    IITA Subjects
    Cassava; Disease Control; Pests Of Plants
    Agrovoc Terms
    Insecta; Biological Control; Parasitoids; Cassava Mealybug; E. Lopezi
    Regions
    Africa; West Africa
    Countries
    Namibia; Nigeria
    Journals
    Environmental Entomology
    Collections
    • Journal and Journal Articles4835
    copyright © 2019  IITASpace. All rights reserved.
    IITA | Open Access Repository