Pollination of the cycad Zamia incognita A. Lindstr. & Idárraga by Pharaxonotha beetles in the Magdalena Medio Valley, Colombia: a mutualism dependent on a specific pollinator and its significance for conservation

• Published in: Arthropod-plant interactions Vol. 11; no. 5; pp. 717 - 729
• Main Authors: Valencia-Montoya, Wendy A., Tuberquia, Dino, Guzmán, Pablo Andrés, Cardona-Duque, Juliana
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2017; Springer Nature B.V
• Subjects: Beetles; Behavioral Sciences; Biological effects; Biomedical and Life Sciences; Circadian rhythms; Coleoptera; Cones; Conservation; Dispersal; Ecology; Elongation; Entomology; Females; Fluorescence; Fluorescent dyes; Fluorescent indicators; Habitat loss; Insects; Invertebrates; Life cycle engineering; Life cycles; Life Sciences; Mutualism; Original Paper; Ornamental plants; Plant extracts; Plant Pathology; Plant reproduction; Plant Sciences; Pollen; Pollination; Pollinators; Population studies; Reinforcement; Shedding; Viability; Wildlife conservation; Wind; Colombia; Plant thermogenesis; Cycad pollination; Erotylidae; Plant-insect interactions
• ISSN: 1872-8855; 1872-8847
• DOI: 10.1007/s11829-017-9511-y

The genus
Zamia
(Zamiaceae: Cycadales) exhibits its greatest diversity in Colombia and is highly threatened by habitat loss, extraction for ornamental plant trade, and mining, among other factors. One of the most important considerations for the effective conservation of
Zamia
is its highly specialized reproductive biology. Despite the importance of pollination for the populations’ viability, no studies have examined the pollination process of cycads in Colombia. Herein, we describe the pollination process of
Zamia incognita
A. Lindstr. & Idárraga, in a natural population. Exclusion experiments were performed by selectively excluding wind, beetles, both, or neither, which demonstrated that
Pharaxonotha
beetles are effective pollinators of
Zamia incognita
and that wind does not play any role as pollen vector. By following beetles marked with fluorescent dyes and directly observing beetle movements on and into female cones and micropyles, we confirmed that
Pharaxonotha
sp. is the effective pollinator of
Z. incognita
. The beetles traveled a maximum dispersal distance from a male to female cone of nearly 22 m and a minimum distance of 5 m. We found
Pharaxonotha
beetles in male cones, where they complete their life cycle. Cones produce heat in a circadian pattern associated with the elongation of the cones and pollen shedding. The increase in cones’ temperature appears to play an important role in beetle attraction. We suggest that pollination droplets on the micropyles would be a reward to pollinators. We also discuss the relationship of this
Zamia
species with other insects, which have important consequences for the conservation of web interactions.