A house in the tropics: full pension for ants in Piper plants / Una casa en el tropico:pensión completa para hormigas en plantas de Piper

Autor(en)

Renate Fischer, Veronika Mayer

Abstrakt

On the southern Pacific slope of Costa Rica, several species of Piper plants (Piperaceae) live in an obligate mutualism

with Pheidole bicornis ants (Fomicidae: Myrmicinae). These plants produce small single-celled food bodies (FBs) in the leaf domatia

formed by the petiole bases and roofing leaf sheaths. FBs of four of the five Piper species known to live with the obligate ant

mutualist Pheidole bicornis were analysed: P. cenocladum, P. fimbriulatum, P. obliquum and P. sagittifolium. FBs mainly consist of lipids

(41% to 48% of dry mass (DM)) and proteins (17% to 24%) and are a high-energy food source (up to 23 kJ g-1 DM) for the inhabiting

ants. By measuring the natural abundance of the stable (i.e. non-radioactive) isotopes of carbon (13C) and of nitrogen

(15N) in FBs of Piper fimbriulatum and in ants it was shown that especially the larvae of the ants mainly feed on FBs. By feeding

inhabiting ants with the 15N-labelled amino acid glycine, which was supplied in sucrose solution to the ants, nutrient transfer was

demonstrated not only from plants to ants via FBs but also from ants to plants via faeces. Nutrient transfer from ants to plants occurred

remarkably fast. Within 6 days, up to 25% of the nitrogen ingested by the ants was incorporated by the plants. However,

the provision of nitrogen by symbiotic ants to the Piper species accounted for a minimum daily input rate of 0.8% of the plant¿s

above-ground nitrogen uptake, which is only of minor importance for the plant partner. On the other hand, only a minute part

of the above-ground biomass is actually invested in food for ants. Hence, the energy and material investment in food bodies of

Piper plants may be compensated by the ant-derived nitrogen.

Organisation(en)

Seiten

589-598

Anzahl der Seiten

Publikationsdatum

2008

ÖFOS 2012

106054 Zoologie, 106008 Botanik, 106030 Pflanzenökologie

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