Translator Disclaimer
1 February 2008 Imported Fire Ant (Hymenoptera: Formicidae) Mound Shape Characteristics Along a North–South Gradient
Author Affiliations +
The nests of some mound-building ants are thought to serve an important function as passive solar collectors. To test this hypothesis, imported fire ant (Solenopsis invicta Buren, S. richteri Forel, and their hybrid) mound shape characteristics (south facing slope angle and area, mound height, and basal elongation in the plane of the ground) were quantified in 2005 and 2006 at a number of locations from ≈30°25′ N (Long Beach, MS) to 35°3′ N (Fayetteville, TN). Insolation (w*h/m2), maximum sun angle (sun elevation in degrees above the horizon at noon, dependent on date and latitude), cumulative rainfall (7 and 30 d before sampling), and mean ambient temperature (7 d before sampling) for each site × date combination were used as predictive variables to explain mound shape characteristics. Steepness of south-facing mound slopes was negatively associated with maximum sun angle at higher temperatures, with predicted values falling from ≈36° at sun angle = 40° to 26° at sun angle = 70°; at lower temperatures, slope remained relatively constant at 28°. On average, mound height was negatively correlated with maximum sun angle. Rainfall had a net negative effect on mound height, but mound height increased slightly with maximum sun angle when rainfall was high. Mound elongation generally increased with increased mound building activity. Under favorable temperature conditions and average rainfall, imported fire ant mounds were tallest, most eccentric, and had the steepest south facing slopes during periods of low maximum sun angle. Mound shape characteristics are discussed with regard to season and their potential usefulness for remote sensing efforts.
James T. Vogt, Bradley Wallet and Thomas B. Freeland "Imported Fire Ant (Hymenoptera: Formicidae) Mound Shape Characteristics Along a North–South Gradient," Environmental Entomology 37(1), (1 February 2008).[198:IFAHFM]2.0.CO;2
Received: 19 June 2007; Accepted: 29 October 2007; Published: 1 February 2008

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top