Strategies of acacia-ants: to grow or to reproduce?

2011 REU Project:

Mutualistic acacia-ants protect acacia trees from herbivorous animals, competing plants, and pathogenic fungi in return for food and nesting space provided by the plant. In contrast, parasitic ants nest in and feed on acacias but do not protect the plant. What survival strategies do the different ants have and how did these evolve? We will analyze the colony structure of different mutualistic and parasitic acacia ants to see how much each species invests in colony growth (via workers that provide protection) versus reproduction (via sexuals) by counting all the individuals from several previously sampled acacia trees from Mexico. We expect mutualists to invest in more protection and the parasites to invest more in reproduction. We also expect to find diverse communities of organisms (e.g. other ants, caterpillars, silverfishes, etc.) on acacias inhabited by parasites, while mutualists should exclude other organisms from their hosts. Also, we will infer the phylogenetic history of the ants to assess how the different survival strategies evolved.

Research methods and techniques: Interns will learn to distinguish different ant species from one another and learn the gross recognition of different insect orders. Moreover, determination of castes and life stages in ants will be practiced and all individual ants and other insects counted to determine colony composition. Skills regarding the design of scientific research and methods of insect curation will be emphasized. Interns may also receive training in DNA extraction, PCR, and sequencing in the Museum’s core genetics facility, the Pritzker Laboratory and the DNA Discovery Center depending on the findings from the colony/species counts.

Curator/Advisors: Dr. Corrie S. Moreau, Dr. Stefanie Kautz, and Benjamin E. Rubin, Zoology, Insects