Wing Pattern Evolution and the Origins of Mimicry of North American Admirals
Admiral butterflies (genus Limenitis) are a particularly appealing system to address questions regarding wing pattern evolution and speciation. This genus is unusual among other butterflies in that mimicry has evolved multiple times and hybridization is frequent between wing pattern forms.
An interesting fact of wing pattern evolution within this genus is the apparent differences between the largely stereotypic Paleartic fauna and the highly variable Nearctic forms of butterflies.
Palearctic and Nearctic forms regard to different ecozones dividing the earth’s land surface. The Palearctic is the largest ecozone. It includes Europe, Asia north of the Himalaya, northern Africa, and the northern and central parts of the Arabian Peninsula. The Nearctic ecozone covers most of North America, including Greenland and the highlands of Mexico, Southern Mexico, Southern Florida, Central America, and the Caribbean islands together with South America.
The Palearctic forms have a uniformly dark brown or black background wing color with one major band of white pigment running across both the dorsal and ventral surfaces of the wings. Variations among these species is predominately subtle in variations of this white-band wing pattern.
In contrast, wing patterns in Nearctic forms are diverse. There are three lineages of mimicry in admiral butterflies that occur in North America which may have played a large role in the diversification of this group.
The most recognized example of mimicry among the North American Limenitis butterflies is the relationship between the Viceroy butterfly and the Monarch butterfly. In the Monarch butterflies they are said to be foul tasting and poisonous due to the presence of cardenolides in their body, which they ingest as they feed on milkweed. In the viceroy butterflies they feed on Salicaceae plants and ingest salicylic acid in their bodies which makes them bitter and upsets predators stomachs. This is said to be a classic example
An interesting fact of wing pattern evolution within this genus is the apparent differences between the largely stereotypic Paleartic fauna and the highly variable Nearctic forms of butterflies.
Palearctic and Nearctic forms regard to different ecozones dividing the earth’s land surface. The Palearctic is the largest ecozone. It includes Europe, Asia north of the Himalaya, northern Africa, and the northern and central parts of the Arabian Peninsula. The Nearctic ecozone covers most of North America, including Greenland and the highlands of Mexico, Southern Mexico, Southern Florida, Central America, and the Caribbean islands together with South America.
The Palearctic forms have a uniformly dark brown or black background wing color with one major band of white pigment running across both the dorsal and ventral surfaces of the wings. Variations among these species is predominately subtle in variations of this white-band wing pattern.
In contrast, wing patterns in Nearctic forms are diverse. There are three lineages of mimicry in admiral butterflies that occur in North America which may have played a large role in the diversification of this group.
The most recognized example of mimicry among the North American Limenitis butterflies is the relationship between the Viceroy butterfly and the Monarch butterfly. In the Monarch butterflies they are said to be foul tasting and poisonous due to the presence of cardenolides in their body, which they ingest as they feed on milkweed. In the viceroy butterflies they feed on Salicaceae plants and ingest salicylic acid in their bodies which makes them bitter and upsets predators stomachs. This is said to be a classic example