Publicação
The endemic parasitoids of the chestnut gall wasp Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) in Portugal and biocontrol with Torymus sinensis Kamijo (Hymenoptera: Torymidae)
| Resumo: | The chestnut gall wasp Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) is a gall inducing insect original from China that attacks the Castanea genus and can significantly hinder production of chestnut trees. Because of its characteristic life cycle, in which D. kuriphilus spends most of its life inside the protection of its galls, the use of conventional methods of pest control, such as pesticides, is highly ineffective, making biocontrol methods the only viable option for the management of this pest. The most effective and used method of biocontrol of D. kuriphilus is based on the releases of Torymus sinensis Kamijo (Hymenoptera: Torymidae), a natural parasitoid of D. kuriphilus also original from China. This work aims to study the communities of native parasitoids associated with D. kuriphilus, the effect of the presence of oak trees in their communities and their effectiveness in the pest control, as well as the effect of T. sinensis releases in the populations of D. kuriphilus in the Portuguese region of Entre Douro e Minho. To analyse the communities of native parasitoids, 9 sampling sites were selected in 3 counties (Braga, Barcelos and St. Tirso) in the Entre Douro e Minho region, 4 of which had the presence of oak trees. To evaluate the effect of T. sinensis in the populations of D. kuriphilus, 3 releases were made in 3 sites in the Barcelos and Viana do Castelo counties. Some correlation has been found between the presence of oak trees in the surroundings of the sampling sites and the diversity and abundance of native parasitoid species found in galls in chestnut trees, and between this diversity and abundance and the number of D. kuriphilus found. Presence of T. sinensis was found in the 3 out of 3 sites of release one year after the releases, and in 2 out of 3 sites two years after the releases. No effect was noticed in the populations of D. kuriphilus neither on the native parasitoids communities in the 3 sites. Further studies are needed both in the analysis of the native parasitoid communities associated with D. kuriphilus and to better comprehend the effects of T. sinensis releases in the D. kuriphilus populations and its associated native parasitoid communities. |
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| Autores principais: | Cardoso, João Filipe Soares |
| Assunto: | Ciências Naturais::Ciências Biológicas |
| Ano: | 2020 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | The chestnut gall wasp Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) is a gall inducing insect original from China that attacks the Castanea genus and can significantly hinder production of chestnut trees. Because of its characteristic life cycle, in which D. kuriphilus spends most of its life inside the protection of its galls, the use of conventional methods of pest control, such as pesticides, is highly ineffective, making biocontrol methods the only viable option for the management of this pest. The most effective and used method of biocontrol of D. kuriphilus is based on the releases of Torymus sinensis Kamijo (Hymenoptera: Torymidae), a natural parasitoid of D. kuriphilus also original from China. This work aims to study the communities of native parasitoids associated with D. kuriphilus, the effect of the presence of oak trees in their communities and their effectiveness in the pest control, as well as the effect of T. sinensis releases in the populations of D. kuriphilus in the Portuguese region of Entre Douro e Minho. To analyse the communities of native parasitoids, 9 sampling sites were selected in 3 counties (Braga, Barcelos and St. Tirso) in the Entre Douro e Minho region, 4 of which had the presence of oak trees. To evaluate the effect of T. sinensis in the populations of D. kuriphilus, 3 releases were made in 3 sites in the Barcelos and Viana do Castelo counties. Some correlation has been found between the presence of oak trees in the surroundings of the sampling sites and the diversity and abundance of native parasitoid species found in galls in chestnut trees, and between this diversity and abundance and the number of D. kuriphilus found. Presence of T. sinensis was found in the 3 out of 3 sites of release one year after the releases, and in 2 out of 3 sites two years after the releases. No effect was noticed in the populations of D. kuriphilus neither on the native parasitoids communities in the 3 sites. Further studies are needed both in the analysis of the native parasitoid communities associated with D. kuriphilus and to better comprehend the effects of T. sinensis releases in the D. kuriphilus populations and its associated native parasitoid communities. |
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