Narrative

Milkweed butterflies (Danaid family) are found throughout the world. Although the United States has only a few species (including the common and well-known Monarch), countries like Malaysia and Taiwan have over a dozen species each in this family.

Most of the species in the Danaus and Idea genera can be identified by picture matching. However, the Euploea genus has some complex identification problems enhanced by geographical dimorphism. Species in Malaysia, for example, tend to look alike, and the same species when found in Borneo will look totally different and yet similar to each other. For further research one can refer to plate 23 of The Butterflies of the Malay Peninsula by Corbet and Pendlebury which states: Indeed, in such cases it is easier to ascertain the country of origin of a specimen than to determine its specific identity,

The task of identifying a group of Euploea butterflies from a specific place can be helped by the following tips. The trailing edge of the forewing in many Euploea species is rounded in the male and straight in the female. This will easily and quickly permit one to sex and match many of the specimens as the dot patterns are usually similar across the sexes. The male sex brand near the trailing edge of the wing on the dorsal side in male specimens is also useful for identification purposes. The double sex brand is unique to the Euploea sylvester/dufresne complex. A single large sex brand might indicate a specimen in the E. algea group.

Taxonomy

References