Adaptation of Camponotus floridanus’ Cuticular Hydrocarbon Profile under High Temperature Conditions

Insects are small creatures highly susceptible to water loss. A major factor in the prevention of water loss through an insect’s cuticle are their cuticular hydrocarbons (CHC), a lipid layer consisting mostly of long-chain hydrocarbons. CHCs consist of different molecules called alkanes, alkenes, and methyl branched hydrocarbons which all have varying levels of hydrophobicity. Ants are a massively abundant family of insects with important roles in the ecosystem that also utilize CHCs. Camponotus floridanus isare athe native ant species of the Florida Keys which areis known to have variable environmental temperature. Being exposed to temperatures as high as 35 °C, these ants are expected to have mechanisms that allow them to adapt to their environment. It was hypothesized that CHCs may change in concentration or composition as a means to combat the changes in cuticular permeability due to the variable temperatures that the ants experience. We therefore used C. floridanus worker ants to learn more about CHC plasticity in insects when exposed to elevated temperatures. We found four CHC componentspeaks that showed a statistically significant increase in concentration when comparing the control to treatment colonies: 3,7 dimethyl C31, an underdetermined methyl branched C31, 3,7,11 trimethyl C31, and an undetermined tetramethylbranched C31. These significant changes in concentration occurred on longer chain hydrocarbons. Under further examination, it was found that there was a strong positive correlation between elution time and the differences in medians of peak area between control and treatment colonies. This shows that there was a shift in the CHC profile resulting in an increased concentration of longer chained methyl-branched hydrocarbons. It also suggests that branched hydrocarbons also play some role in the water proofing mechanism of C. floridanus.