Relative impact of spider predation and cover crop on population dynamics of Erythroneura variabilis in a raisin grape vineyard

cg.authorship.typesCGIAR and advanced research instituteen
cg.contributor.affiliationInternational Institute of Tropical Agricultureen
cg.contributor.affiliationUniversity of Californiaen
cg.contributor.affiliationCalifornia Department of Food and Agricultureen
cg.creator.identifierRachid Hanna: 0000-0002-5715-0144
cg.identifier.doihttps://doi.org/10.1046/j.1570-7458.2003.00051.xen
cg.isijournalISI Journalen
cg.issn0013-8703en
cg.issue3en
cg.journalEntomología Experimentalis et Applicataen
cg.reviewStatusPeer Reviewen
cg.subject.iitaPESTS OF PLANTSen
cg.subject.iitaGRAIN LEGUMESen
cg.volume107en
dc.contributor.authorHanna, R.en
dc.contributor.authorZalom, F.en
dc.contributor.authorRoltsch, W.en
dc.date.accessioned2020-03-12T10:06:20Zen
dc.date.available2020-03-12T10:06:20Zen
dc.identifier.urihttps://hdl.handle.net/10568/107610
dc.titleRelative impact of spider predation and cover crop on population dynamics of Erythroneura variabilis in a raisin grape vineyarden
dcterms.abstractExperimental and correlative evidence has steadily mounted over the past 30 years implicating spiders in the suppression of insect herbivore pests in crop fields. A large body of evidence has also shown that increasing agroecosystem vegetation diversity often influences the abundance of herbivores and their natural enemies. In previous experiments, the abundance of several species of spiders on grapevines in a raisin grape vineyard was twofold enhanced in vineyard plots vegetationally diversified with a cover crop. A concomitant reduction in the abundance of the leafhopper pest Erythroneura variabilis Beamer was observed on grapevines in the diversified plots, but a causal relationship was not established. In the present study, we simultaneously manipulated spider densities (in open-vine spider exclusion and vine-shoot enclosures) and ground cover to determine their relative impact on E. variabilis population dynamics. Open-vine spider exclusion resulted in an average 35% increase in the density of E. variabilis the greatest effect with occurring during the first and second leafhopper generations. The negative impact of spiders on E. variabilis densities was corroborated with vine-shoot enclosure experiments. Under the conditions of the present study, the cover crop per se did not affect the dynamics of E. variabilis populations on grapevines, despite a 1.6-fold increase in spider densities on vines in cover crop plots, compared with vines in bare ground plots, probably due to insufficient spider enhancement and low overall E. variabilis abundance during the summer months. The cover crop had little effect on vine macronutrient status (and presumably vine water status). While this study provided further support for the hypothesis that vegetation diversity can enhance spider abundance, this enhancement does not always lead to lower pest densities, thus underscoring the complexity and variability that exists in interactions involving cover crop, spiders, and crop plants and their herbivore pests.en
dcterms.accessRightsLimited Access
dcterms.available2003-05-22
dcterms.bibliographicCitationHanna, R., Zalom, F. & Roltsch, W. (2003). Relative impact of spider predation and cover crop on population dynamics of Erythroneura variabilis in a raisin grape vineyard. Entomologia Experimentalis et Applicata, 107(3), 177-191.en
dcterms.extent177-191en
dcterms.issued2003-06
dcterms.languageen
dcterms.licenseCopyrighted; all rights reserved
dcterms.publisherWileyen
dcterms.subjectcover cropsen
dcterms.subjectspidersen
dcterms.subjecterythroneuraen
dcterms.subjectraisinsen
dcterms.subjectvineyardsen
dcterms.typeJournal Article

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