A mutualism with a native membracid facilitates pollinator displacement by Argentine ants

Lach, Lori (2007) A mutualism with a native membracid facilitates pollinator displacement by Argentine ants. Ecology, 88 (8). pp. 1994-2004.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: http://dx.doi.org/10.1890/06-1767.1


The loss of biodiversity and associated ecosystem services are major threats posed by the spread of alien invasive species. Invasive ants are frequently associated with declines in the diversity of ground-dwelling arthropods but also may affect plants through their attraction to floral nectar and tending of hemipterans. Protea nitida is a tree native to the South African fynbos that hosts a native membracid, Beaufortiana sp., which is tended by ants. Here I compare Argentine ants (Linepithema humile) to native ants in their attraction to P. nitida inflorescences in the presence and absence of the membracid, and their effects on other floral arthropod visitors, seed set, and ovule predation. Argentine ant discovery of inflorescences increased at least 13-fold when membracids were present on the branch, whereas native ant discovery of inflorescences was only doubled by membracid presence at one site in one study year and was unaffected in the other three site-years. Excluding Argentine ants from inflorescences resulted in an increase in several arthropod taxa and potential pollinators; native ant exclusion had no positive effects. Thus the mutualism between Argentine ants and the membracid is facilitating pollinator deterrence by the ants. Though Argentine ants were not associated with a decline in P. nitida seed set or ovule predation, declines in generalist insect pollinators may have ramifications for the 83% of fynbos plants that are insect pollinated. Pitfall traps showed that Argentine ants were not more abundant than native ants in non-invaded sites. Focusing only on abundance on the ground and displacement of ground-dwelling arthropod fauna may lead to an underestimate of the effects of invasive ants on their adopted communities.

Item ID: 29873
Item Type: Article (Research - C1)
ISSN: 1939-9170
Keywords: biological invasion, facilitation, flowers, fynbos, Hemiptera, Linepithema humile;, nectar-thieving, ovule predation, pollinators, seed set
Date Deposited: 05 Nov 2013 23:53
FoR Codes: 05 ENVIRONMENTAL SCIENCES > 0501 Ecological Applications > 050103 Invasive Species Ecology @ 25%
06 BIOLOGICAL SCIENCES > 0602 Ecology > 060202 Community Ecology (excl Invasive Species Ecology) @ 50%
06 BIOLOGICAL SCIENCES > 0602 Ecology > 060201 Behavioural Ecology @ 25%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960899 Flora, Fauna and Biodiversity of Environments not elsewhere classified @ 100%
Downloads: Total: 7
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page