Social Parasitism : Blue Butterflies in Ant Colonies
Biology 342 Fall 2011
Ellen Levkoy & Rachel Strominger
Maculinea blues and their Myrmica ant colony hosts
Blue Butterflies of the Maculinea species inhabit Mymrica ant colonies during its caterpillar and coccoon stages before it metamorphoses into a butterfly. This rare butterfly uses different Myrmica supspecies ant hosts across its wide European range. The caterpillars must be “adopted” and taken into an ant nest in order to survive to adulthood. This parasitic dependence has led to species differentiation based on slight variations and adaptations to those variations among Maculinea subspecies [7, 8]. Maculinea rebeli has adapted a mimetic strategy, using chemical and acoustical signals that allow it to gain acceptance in the ant community and to elevate its social status within the caste hierarchy of the nest .
This complex parasitic strategy makes Maculinea vulnerable to variation in access to ant colonies, which has led to adaptive radiation and to a decline in populations throughout its range. Habitat disruption and destruction have made it more difficult for Maculinea butterflies to locate appropriate Myrmica ant colonies. This has increased the need for understanding the myrmecophilic behavior of Maculinea but paradoxically and problematically made it harder to locate and study the behavior and to differentiate between similar relationships among closely related ant and butterfly species. [12, 4]
Questions for Understanding the Behavior
Myrmecophily, the parasitic infiltration of Myrmica ant colony nests by Maculinea butterfly larvae, is a complex behavior. In this website, information can be found that explores the behavior in terms of Tinbergen’s four questions of animal behavior, a widely used model for viewing multifaceted behaviors :
Mechanism: mechanistic explanations of organismic structures and how they function.
Ontogeny: developmental explanations of sequential changes in individuals across their lifetime.
Phylogeny: phylogenetic explanations for sequentials changes in a species over time.
Adaptive Value: evolutionary explanations for why an organism exhibits a specific behavioral trait.
Throughout the website, the myrmecophilous behavior is explored. Current understanding indicates that this parasitic behavior is not beneficial to the Myrmica ant species.
image: Maculinea butterfly.