Endozoochory by beetles: a novel seed dispersal mechanism

† Background and Aims Due in part to biophysical sized-related constraints, insects unlike vertebrates are seldom expected to act as primary seed dispersers via ingestion of fruits and seeds (endozoochory). The Mediterranean parasitic plant Cytinus hypocistis, however, possesses some characteristics...

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Detalles Bibliográficos
Autores: Vega, Clara de, Arista, Montserrat, Ortiz, Pedro L., Herrera, Carlos M., Talavera, Salvador
Tipo de recurso: artículo
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/36742
Acceso en línea:http://hdl.handle.net/10261/36742
Access Level:acceso abierto
Palabra clave:Beetles
Cytinus hypocistis
Cytinaceae
endozoochory
Mutualism
Parasitic plants
Pimelia costata
plant – animal interaction
Seed dispersal
seed viability
Tenebrionidae
Descripción
Sumario:† Background and Aims Due in part to biophysical sized-related constraints, insects unlike vertebrates are seldom expected to act as primary seed dispersers via ingestion of fruits and seeds (endozoochory). The Mediterranean parasitic plant Cytinus hypocistis, however, possesses some characteristics that may facilitate endozoochory by beetles. By combining a long-term field study with experimental manipulation, we tested whether C. hypocistis seeds are endozoochorously dispersed by beetles. † Methods Field studies were carried out over 4 years on six populations in southern Spain. We recorded the rate of natural fruit consumption by beetles, the extent of beetle movement, beetle behaviour and the relative impor- tance of C. hypocistis fruits in beetle diet. † Key Results The tenebrionid beetle Pimelia costata was an important disperser of C. hypocistis seeds, consum- ing up to 17.5 % of fruits per population. Forty-six per cent of beetles captured in the field consumed C. hypocistis fruits, with up to 31 seeds found in individual beetle frass. An assessment of seeds following passage through the gut of beetles indicated that seeds remained intact and viable and that the proportion of viable seeds from beetle frass was not significantly different from that of seeds collected directly from fruits. † Conclusions A novel plant – animal interaction is revealed; endozoochory by beetles may facilitate the dispersal of viable seeds after passage through the gut away from the parent plant to potentially favourable underground sites offering a high probability of germination and establishment success. Such an ecological role has until now been attributed only to vertebrates. Future studies should consider more widely the putative role of fruit and seed ingestion by invertebrates as a dispersal mechanism, particularly for those plant species that possess small seeds.