Ants tend ghost orchids: patrolling of Dendrophylax lindenii (Orchidaceae) by Crematogaster ashmeadi in Florida

  • Peter R. Houlihan University of Florida
  • Andrea Lucky University of Florida
  • Mike Owen Florida State Park Service
  • Thomas C. Emmel Florida Museum of Natural History, University of Florida

Abstract

Myriad symbioses exist between insects and orchids, especially in tropical forests where the majority of species are epiphytic. Relationships between ants and rare epiphytic orchids are underrepresented in the scientific literature. The natural history and ecological entomology of Florida’s endangered and epiphytic ghost orchid, Dendrophylax lindenii (Lindley) Bentham ex Rolfe (Orchidaceae), remain limited. Widely recognized for long-standing hypotheses concerning the species’ pollination ecology, that documentation recently overturned, other interactions between insects and ghost orchids are scarce. Here we describe the first associations between ants, Crematogaster ashmeadi Mayr (Hymenoptera: Formicidae), and D. lindenii. Ghost orchid roots provide facultative and opportunistic structures for arboreal ants to use in nesting. Furthermore, excrement from ant colonies within the root mass can increase nutrient availability in the orchid’s nutrient-poor substrate; the proximity of these ants permits patrolling to defend the plant and exert control over possible extra floral nectaries that require further inquiry. This study presents novel observations that expand the known insect associations with ghost orchids, elucidating the complex ecology of one of Florida’s rarest and most endangered species.

 

Resumen

Existen incontables números de simbiosis entre insectos y orquídeas, especialmente en los bosques tropicales donde la mayoría de las especies son epífitas. Las relaciones entre las hormigas y las orquídeas epífitas más raras están subrepresentadas en la literatura científica. La historia natural y la entomología ecológica de la orquídea fantasma epífita, Dendrophylax lindenii (Lindley) Bentham ex Rolfe (Orchidaceae), que esta en peligro de extinción en la Florida, siguen siendo limitadas. Ampliamente reconocida por mucho tiempo por las hipótesis sobre la ecología de la polinización de la especie, la documentación fue recientemente anulada y otras interacciones entre insectos y orquídeas fantasmas son escasas. Aquí describimos las primeras asociaciones entre las hormigas, Crematogaster ashmeadi Mayr (Hymenoptera: Formicidae) y D. lindenii. Las raíces de orquídeas fantasmas proporcionan estructuras facultativas y de oportunidad para que las hormigas arbóreas las usen en la anidación. Además, el excremento de las colonias de hormigas dentro de la masa de la raíz puede incrementar la disponibilidad de nutrientes en el sustrato pobre nutritivo de la orquídea; la proximidad de estas hormigas permite patrullar para defender la planta y ejercer control sobre posibles nectarios extra florales que requieren de una mayor investigación. Este estudio presenta observaciones novedosas que amplían las asociaciones de insectos conocidos con las orquídeas fantasmas, aclarando la compleja ecología de una de las especies más raras y en peligro de extinción de la Florida.

Key Words: ants; arboreal; ecology; epiphyte; Everglades; Fakahatchee

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Author Biographies

Andrea Lucky, University of Florida

Dr. Andrea Lucky
Assistant Professor, Insect Systematics

Department of Entomology & Nematology

I am an evolutionary biologist and biodiversity scientist with a focus on insects and invasion, and my training is specifically in the evolution of ants. The tools I use range from insect morphology to molecular genetics to phylogenetic statistics to micro-CT scanning. These tools allow me to answer questions about the relationships among different species of ants and the timing of diversification that have led to the distribution patterns we see today.In addition to my research interests, a major goal of my work is to make science accessible and available to the general public, particularly to make the process of ‘doing’ science accessible to non-scientists.

http://entnemdept.ufl.edu/people-directory/andrea-lucky/

Mike Owen, Florida State Park Service

Park Biologist, Fakahatchee Strand Preserve State Park (1992-present)

Ghost orchid expert

Thomas C. Emmel, Florida Museum of Natural History, University of Florida

Dr. Thomas C. Emmel was the founding director of the McGuire Center for Lepidoptera and Biodiversity, and professor emeritus of Zoology and Entomology at the University of Florida.  Recently deceased, Dr. Emmel was an international expert on tropical ecology, population biology, insect conservation, and Lepidoptera.

Published
2020-09-25
Section
Research Papers