Cheating in mutualism: defection of Yucca baccata against its yucca moths

Citation
T. Bao et Jf. Addicott, Cheating in mutualism: defection of Yucca baccata against its yucca moths, ECOL LETT, 1(3), 1998, pp. 155-159
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
1
Issue
3
Year of publication
1998
Pages
155 - 159
Database
ISI
SICI code
1461-023X(199811)1:3<155:CIMDOY>2.0.ZU;2-B
Abstract
Yucca baccata cheats in its obligate pollination/seed predation mutualism w ith yucca moths. Although all individuals use the pollination services of y ucca moths, many individuals do not reciprocate in sustaining yucca moth la rvae. Cheating is associated with the morphology of Y. baccata pistils. In Y. baccata, the apex of the ovary contains only inviable ovules, and there are two distinct flower types, one of which has twice as many potentially v iable ovules as the other. Because yucca moths oviposit at the apex of Y. b accata ovaries, larvae in flowers with few viable ovules fail to encounter viable ovules and therefore perish. Inflorescences generally have just one flower type, implying that some individuals cheat whereas others maintain t he yucca moth population. Our most surprising observation, however, is that although the proportion of cheaters should be low, over 70% of Y. baccata individuals cheat. Me hypothesize that both density- and frequency-dependen t processes maintain a balance of cheaters and noncheaters in this system.