Meeting Abstract

64.5  Saturday, Jan. 5  Found or Fly: flight, reproduction and biomechanical tradeoffs in ant queens HELMS IV, J.A.*; KASPARI, M.; University of Oklahoma; University of Oklahoma

Because of a diversity of reproductive strategies, the ants [Formicidae] are an ideal system to study reproductive tradeoffs. In a typical species, a young queen performs two competing, yet intimately related tasks. First, in the flight phase, she must fly to mate, disperse and locate a new nest site. Second, in the foundation phase, she must found a colony, lay eggs and rear the first batch of workers. Many colony foundation strategies are known, but we lack a quantitative framework linking reproduction to flight morphology. Here we introduce the Found or Fly (FoF) Hypothesis, which posits a fitness tradeoff in ant queens between colony foundation and flight performance, manifest through investment in gaster mass. We investigated queen morphology of a common Neotropical species, Azteca instabilis, to evaluate the assumptions of FoF. Gaster mass varied among queens, with time of year, and independently of body size, consistent with individual or colony level manipulation. Several measures of flight ability- flight muscle ratio, wing loading, and drag- were adversely affected by increased gaster mass. Second, we characterized the flight morphology of a hyperdiverse tropical assemblage. Flight morphology accurately predicted colony foundation strategy among the ants. Due to gaster investment, several species carried extremely large loads relative to flight muscle mass, pushing theoretical limits of insect flight. These results confirm the tight relationship between foundation and flight, and suggest that biomechanical flight requirements may constrain reproductive strategies in the ants.