Research: Christine Johnson

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Formica truncorum

The wood ant Formica truncorum is facultatively polygynous; populations are comprised of only single-queen colonies, only multiple-queen colonies or both monogyne and polygyne colonies. The two types of colonies represent alternative life histories that pose a compromise between reproduction and survival. New queens from monogyne colonies typically disperse from the nest and found new colonies alone; new queen from polygyne tend to forgo dispersal and remain in their natal nest where reproduction is shared. Species that maintain such discrete populations of monogyne or polygyne social structures provide a unique opportunity to infer the foundation for these diverging life-history strategies by identifying basic differences in behavior, chemistry and physiology. One focus of my work has been on examining the developmental trajectory in alary musculature of new gynes from discrete monogyne and polygyne populations to assess potential limitations on dispersal ability. My study with Lotta Sundström at the University of Helsinki and Johan Billen at the Catholic University of Leuven revealed that just after emergence, when gynes are still considered 'callow' (between 0-7 days post eclosion when the cuticle is not yet hardened and has a yellowish hue), there were no differences in number of mitochondria or sarcomeres seen in the ultra-thin sections of thoracic musculature. However, as development proceeds, the differences in muscle changed dramatically with new gynes from polygyne nests having significantly fewer mitochondria and, in dealates, more rapid degeneration of tissue. For more information see Johnson et al. 2005.

Classification: Formicidae: Formicinae: Formicini: Formica

References: Johnson, CA, Sundström, L, & Billen, J. 2005 Development of alary musculature in single and multiple queen populations of Formica truncorum. Annales Zool. Fennici, 42: 225-234. pdf - read only