RESUMEN
The 16SrIV-A phytoplasmas are associated with the devastating disease lethal yellowing (LY) of palms. In Tabasco (Mexico), the death of Cocos nucifera, Adonidia merrillii, and Attalea butyracea palms have been suspected to be associated with LY based on symptomatology. Samples from the trunk of both symptomatic and nonsymptomatic palms were collected in three different environments: two species of palms within a rural zone and the other within an urban zone. DNA was extracted to perform a nested PCR with phytoplasma primers P1/P7-LY16SF/R16R2. A 1,345-bp fragment was amplified from the DNA extracted from each of the 29 LY-symptomatic palms sampled. Phytoplasma identification was achieved by amplicon sequencing and virtual restriction fragment length polymorphism analyses. Three 16SrIV phytoplasma subgroups were detected: 16SrIV-A in C. nucifera, 16SrIV-B in A. merrillii, and 16SrIV-D in C. nucifera, A. merrillii, and A. butyracea. Phylogenetic analysis showed also that the three phytoplasma strains found in the palm species clustered with phytoplasmas reported in the literature in the three subgroups identified. This is the first report of phytoplasmas associated with these palm species in Tabasco.
Asunto(s)
Phytoplasma/genética , ADN Bacteriano/genética , México , Filogenia , Enfermedades de las PlantasRESUMEN
The aim of this work was to know the diversity of insects captured by weaver spiders in a plantation of cocoa (Theobroma cacao L.) of 6 ha in the State of Tabasco, Mexico. The study was carried out from July 2004 to June 2005 by means biweekly samples of the insects captured on the spiders webs. The total of 3,041 webs of 54 species of spiders belonging to seven families (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae and Linyphiidae) were revised. We found 1,749 specimens belonging to 10 orders of insects, represented by 93 families, the majority of Coleoptera, Diptera and Hemiptera that constituted 74% of the identified families. The biggest number of specimens of all orders was captured by Araneidae, except of Isoptera, whose specimens were captured mainly by the family Theridiidae. The index of diversity (H'), evenness (J') and similarity (Is), applied to know the diversity of families of insects captured among families of spiders, varied from 0.00 to 3.24, 0.00 to 0.81, and 0.04 to 0.522, respectively. We conclude that there is a wide diversity of insects predated by the weaver spiders in the cocoa agroecosystem, and that there are species that can be promising for the biological control of pests.
Asunto(s)
Cacao , Ecosistema , Insectos , Arañas/fisiología , Animales , Conducta Animal , Control de Insectos , MéxicoRESUMEN
El objetivo de este trabajo fue el de conocer la diversidad de insectos capturados por arañas tejedoras en una plantación de cacao de 6 ha en Tabasco, México. El estudio se realizó de Julio del 2004 a Junio del 2005 mediante recolectas quincenales de los insectos capturados en las telas de las arañas. Se revisaron 3,041 telas de 54 especies de arañas pertenecientes a siete familias (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae y Linyphiidae) que capturaron 1.749 insectos de 10 órdenes, representados por 93 familias, la mayoría de Coleoptera, Diptera y Hemiptera que en conjunto constituyeron el 74 por ciento del total de las familias identificadas. La familia Araneidae fue la que capturó el mayor número de individuos de todos los órdenes, excepto de Isoptera, cuyos individuos fueron capturados principalmente por la familia Theridiidae. Los índices de diversidad (H'), equitatividad (J') y similitud (Is), aplicados para conocer la diversidad de familias de insectos capturados entre familias de arañas, variaron de 0,00 a 3,24, 0,00 a 0.81, y 0,04 a 0,522, respectivamente. Concluimos que existe una amplia diversidad de insectos que son depredados por las arañas tejedoras en el agroecosistema cacao y que hay especies que pueden ser promisorias para el control biológico de plagas.
The aim of this work was to know the diversity of insects captured by weaver spiders in a plantation of cocoa (Theobroma cacao L.) of 6 ha in the State of Tabasco, Mexico. The study was carried out from July 2004 to June 2005 by means biweekly samples of the insects captured on the spiders webs. The total of 3,041 webs of 54 species of spiders belonging to seven families (Araneidae, Theridiidae, Tetragnathidae, Uloboridae, Pholcidae, Dyctinidae and Linyphiidae) were revised. We found 1,749 specimens belonging to 10 orders of insects, represented by 93 families, the majority of Coleoptera, Diptera and Hemiptera that constituted 74 percent of the identified families. The biggest number of specimens of all orders was captured by Araneidae, except of Isoptera, whose specimens were captured mainly by the family Theridiidae. The index of diversity (H'), evenness (J') and similarity (Is), applied to know the diversity of families of insects captured among families of spiders, varied from 0.00 to 3.24, 0.00 to 0.81, and 0.04 to 0.522, respectively. We conclude that there is a wide diversity of insects predated by the weaver spiders in the cocoa agroecosystem, and that there are species that can be promising for the biological control of pests.