Gall size of Dryocosmus kuriphiluslimits down-regulationby native parasitoids

The success of invasive species largelydepends on the resistance offered by the native communities. Dryocosmus kuriphilusis a cynipidnative from China that is a serious pest of chestnuts worldwide. This species recruits natural enemies in theareas of introduction; nevertheless, their role inregulati...

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Detalles Bibliográficos
Autores: Gil-Tapetado, Diego, Castedo-Dorado, Fernando, Nieves-Aldrey, J. L., Lombardero, María Josefa
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/243780
Acceso en línea:http://hdl.handle.net/10261/243780
Access Level:acceso abierto
Palabra clave:Invasive species
Asian chestnut gall wasp
Natural enemies
Gall morphology
Climate Residence time
Descripción
Sumario:The success of invasive species largelydepends on the resistance offered by the native communities. Dryocosmus kuriphilusis a cynipidnative from China that is a serious pest of chestnuts worldwide. This species recruits natural enemies in theareas of introduction; nevertheless, their role inregulating pest population is frequently questioned, although the causes are not clear. We sampled parasitoids from 12,525 galls collected in 192 sitesin four geographic areas differing in climate andresidence time of the wasp of Galicia (NW Iberian Peninsula). We also dissected 2994 galls to assess the effects of gall characteristics on parasitism level. We found a rich community of native enemies thatcontributed to biotic resistance against the invasive:19 species of native parasitoids were feeding on thewasp, with mortalities ranging from 14 to 37%.Rarefaction analyses indicated that this species listaccounts for most of the native enemies that attack D.kuriphilusin inland Galicia. However, percent parasitism of D. kuriphilusby native parasitoids decreasedgreatly with time since introduction. This was becausegalls became larger, more thickly walled, and withmore D. kuriphilusper gall as the abundance of D. kuriphilusincreased. As the galls became larger andmore populated, a declining fraction of the D. kuriphiluswithin were parasitized by native enemies (decrease from [25% parasitism to\2% as gall sizeincreased from 0.2 to 3 cm3). Consequently, native parasitoids may play a role in slowing the invasive atlow densities, but this effect becomes increasingin consequential in highly invaded areas.