Location: Biological Control of Pests ResearchTitle: Colony structure and spatial partitioning of cavity dwelling ant species in nuts of eastern US forest floors Author
Submitted to: Midsouth Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2012
Publication Date: 3/20/2013
Citation: Booher, D., Macgown, J.A., Duffield, R.M. 2013. Colony structure and spatial partitioning of cavity dwelling ant species in nuts of eastern US forest floors. Midsouth Entomologist. 6(1):96. Interpretive Summary: Mississippi is home to at least 190 species of ants, many of which coexist in the same habitat. In order for multiple species to live in close proximity to one another, it is necessary for them to partition the habitat and to have different foraging strategies. The fallen nuts from 30 species of nut bearing trees in this region provide ready-made nest sites for many ant species. During this preliminary study, we collected over 6,000 nuts of walnut, pecan, hickory, and oak on the forest floor at 63 tree sites in Georgia, Maryland, and Mississippi. We collected 36 species of ants including new records for MS and North America in nuts with an average occupancy of 11.6%. We also placed grids of artificial wooden trap nests at sites in these states to compare occupancy rates to the nuts found in the vicinity of the trap nests. We found that the nest traps were comparable in occupancy rates by ants. Nest traps may prove to be a useful method to study colony structure for future studies.
Technical Abstract: Nut-bearing trees create islands of high efficiency, low cost housing opportunities for ant colonies. Fallen nuts in leaf litter from previous seasons provide ready-made nest sites for cavity dwelling ant species, as well as affording protection from the elements. Suitable nuts for nests require an entrance of some type, which may be a simple crack in the shell, or in many cases an emergence hole created by late instar coleopteran and Lepidopteran larvae known to consume the protein rich nut. With over 30 species of southeastern hickories, pecans, chestnuts, walnuts, and oaks; large numbers of suitable nut cavities created by insect feeding; and variation in intraspecific and interspecific nut productivity and nut size; the possible variations of potential nut nesting sites are extensive. A dearth of information is available on colony structure, environmental parameters affecting choices for suitable nest selection sites, negative effects of restricted colony sizes to confined sizes of nuts, and spatial partitioning for nut/cavity inhabiting ant species. Our study aims to answer these basic questions. We collected potential nut-nests from various nut bearing tree species in Maryland, Mississippi, and Georgia. We identified and defined individual trees as a site, took environmental measurements to compare sites, and collected nuts at each site.