Meeting Abstract
A wide array of organisms possess dispersal polymorphisms, where some individuals invest in the physiological machinery needed for dispersal while others lacking this capability instead allocate resources toward alternate life-history traits such as increased reproduction. While the biochemical basis underlying such polymorphisms has been extensively studied in selected insect laboratory populations, actual metabolic dynamics in wild populations are not as well understood. To assess the extent to which laboratory findings correspond to field dynamics, we measured whole-animal metabolic rates and lipid oxidation rates for lab-reared and field-caught dispersal and reproductive morphs in wing-dimorphic Gryllus crickets. All measurements occurred at 27 °C. We found that the dispersal and reproductive morphs maintained comparable mass-specific metabolic rates, but metabolic rates were higher in lab-reared as compared to field-caught crickets. When reared in the laboratory, the dispersal morph was also able to sustain correspondingly greater rates of lipid oxidation. In contrast, no morph differences in lipid oxidation were observed in field-caught crickets. These findings support the conclusion that realized dispersal capability in wild populations can often be strongly constrained by local environmental conditions.
