|Dorsal view - MHNT|
|Ventral view, same specimen|
Their flight is slow and they are reasonably easy to approach, but will fly for some distance if approached too closely.
The upperside of the wings is dark reddish brown with the forewing sometimes having white submarginal spots. The veins are lightly marked with black. Males have a black scent patch on each of the hindwings. The underside of the wings is also dark brown with a postmedian band made up of squarish spots. The soldier has a wingspan of 2 1⁄2 to 3 1⁄2 inches (64–76 mm). D. e. flexaure, formerly D. flexaure, is a subspecies which has more white markings on the hindwing underside.
The queen has nearly no black-marked veins, and has white forewing submarginal spots on both surfaces of the wings.
The soldier may be found in a variety of open, subtropical habitats such as citrus groves, weedy water edges where host plants occur, dry fields, etc.
Males patrol for females. The eggs are bright orange. The black larva is banded with white and yellow stripes. It has a subdorsal row of yellowish-tan spots. There are six black, fleshy filaments, the first pair near the head, the second on the thorax, and the third at the end of the abdomen. The chrysalis is very similar to that of the monarch, often indistinguishable. It has three or more broods per year.
- Strangler vine, Morrenia odorata
- White vine, Funastrum clausum
- West Indian pinkroot, Spigelia anthelmia
- Opler, P. A.; A. D. Warren (2002). "Danaus eresimus". NatureServe. Retrieved 12 July 2013.
- Rick Cech and Guy Tudor (2005). Butterflies of the East Coast. Princeton University Press, Princeton, NJ. ISBN 0-691-09055-6
- Butterflies and Moths Additional Soldier Images
- Bob Stewart, Priscilla Brodkin and Hank Brodkin (2001). Butterflies of Arizona. West Coast Lady Press. ISBN 0-9663072-1-6
- Jim P. Brock and Kenn Kaufman (2003). Butterflies of North America. Houghton Mifflin, New York, NY. ISBN 0-618-15312-8
- James A. Scott (1986). The Butterflies of North America. Stanford University Press, Stanford, CA. ISBN 0-8047-2013-4