Vogt: 3D Characteristics of Fire Ant Mounds 553 THREE-DIMENSIONAL SAMPLING METHOD FOR CHARACTERIZING ANT MOUNDS

A field-portable 3D laser scanner was employed as a means of digitizing the surface of fire ant ( Solenopsis invicta Buren) mounds for analysis of shape and orientation in Mississippi and Oklahoma. Estimates of above-ground mound volume obtained through manual measurements of mound length, width, and height were higher and more variable than estimates obtained by summing the area underneath interpolated mound surfaces. Mounds were typically elliptical in shape and oriented in a north-south direction. The mound apex was offset to the northeast of the mean mound center by an average of 46 ± 5 mm. Additional mound characteristics extracted from 3D data included slope (degrees), surface area, and slope within mound aspect (northeast, southeast, etc.). Advantages of the methodology employed in this study and possible explanations for fire ant mound shape are discussed.