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dc.contributor.authorHammond, W.N.O.
dc.contributor.authorNeuenschwander, P.
dc.date.accessioned2019-12-04T11:36:02Z
dc.date.available2019-12-04T11:36:02Z
dc.date.issued1990
dc.identifier.citationHammond, W.N.O. & Neuenschwander, P. (1990). Sustained biological control of the cassava mealybugPhenacoccus manihoti [Hom.: Pseudococcidae] by Epidinocarsis lopezi [Hym.: Encyrtidae] in Nigeria. Entomophaga, 35(4), 515-526.
dc.identifier.issn0013-8959
dc.identifier.urihttps://hdl.handle.net/20.500.12478/6051
dc.description.abstractFollowing the successful introduction of Epidinocarsis lopezi (De Santis) for biological control of the cassava mealybug (CM) Phenacoccus .manihoti Mat.-Ferr. in southwestern Nigeria in 1981 and 1982, 11 groups of cassava fields were sampled every 2 weeks up to 1988 for impact assessment. After 1984, CM populations remained mostly below 10 per tip despite the presence of native hyperparasitoids, demonstrating the long-term success of biological control by E. lopezi in the region. Indigenous polyphagous coccineilids were found only during peak host densities, whereas the specific E. lopezi was common throughout the year. During some periods, percentage parasitism indicated delayed density dependence. Since 89 % of all sampled cassava tips had no CM at all and the parasitisme is very mobile, parasitization rates were also calculated for individual infested tips (N = 4,878). Parasitism increased slightly with host density on tips having between I and 10 CM of the 3 rd and 4 th instars, indicating positive density dependence. Such tips comprised 64 % of all infested tips. At higher host densities, parasitism rates fell rapidly. The results are discussed in view of different theories on population regulation by biological control agents.
dc.description.sponsorshipInternational Fund for Agricultural Development
dc.description.sponsorshipRome aid agencies of Switzerland
dc.language.isoen
dc.subjectPhenacoccus Manihoti
dc.subjectEpidinocarsis Lopezi
dc.subjectCassava
dc.subjectBiological Control
dc.subjectDensity
dc.titleSustained biological control of the cassava mealybug Phenacoccus manihoti (Hom: Pseudococcidae) by Epidinocarsis lopezi (Hym.: Encyrtidae) in Nigeria
dc.typeJournal Article
dc.description.versionPeer Review
cg.contributor.affiliationInternational Institute of Tropical Agriculture
cg.coverage.regionAfrica
cg.coverage.regionWest Africa
cg.coverage.countryNigeria
cg.authorship.typesCGIAR single centre
cg.iitasubjectCassava
cg.iitasubjectPlant Diseases
cg.iitasubjectPests Of Plants
cg.iitasubjectDisease Control
cg.accessibilitystatusLimited Access
local.dspaceid105981


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