Site hosted by Angelfire.com: Build your free website today!


Insect Mimicry
Links

Insect Mimicry

Batesian Mimicry

Muellerian Mimicry

What is Mimicry?

Mimicry is one of several anti-predatory devices found in nature. Specifically it is a situation in which one species called the mimic resembles in color, form, and/or behavior another species called the model. In doing so, the mimic acquires some survival advantage.

Terms to Know

Mimic: the species that takes on the appearance of another species.
Model: the species that is mimicked
Palatable: sufficiently agreeable in flavor to be eaten
Unpalatable: no suitable for food
Camouflage: to conceal by the use of a disguise that blends in with the surrounding enviornment
Warning Coloration: obvious, recognizable coloration or markings of an animal that serve to warn off potential predators

Types of Mimicry

There are 2 basic forms of mimicry:

1. Batesian - the mimic (palatable) resembles the model (unpalatable) and only the mimic benefits.

2. Mullerian - both the mimic and the model are unpalatable and both benefit.

Batesian mimicry is most effective when the mimic is rare and its emergence follows that of the model. In Mullerian mimicry as density increases so does the adaptive value. Since mimicry provides potential survival value, the mimic with an adaptation that increases the likelihood of surviving is selected. Natural selection of these favorable variations has led to the coevolution of many species. The distinction among camouflage, warning coloration, and mimicry is not always clear. Mimicry, as opposed to camouflage and warning coloration, is specifically the resemblance between two organisms. The same techniques of deception are sometimes utilized in all three anti-predatory devices. These include variations in color, pattern, and structure.

Examples of Mimicry




Batesian

The harmless robber fly (right) resembles the bumblebee (left) even though the two are not closely related. The robber fly is a dipteran, with only a single pair of wings, while the bumblebee is a hymenopteran with two pairs.





Mullerian

The viceroy butterfly (bottom) contains no toxic substances in its body and presumably is quite palatable (one entomologist declared it tastes like dried toast). If so, the viceroy's striking resemblance to the monarch (top) enables it to capitalize on the monarch's unpalatability. (Photos courtesy of Tom Eisner.)