1. Northern New Mexico College
Chemical Analysis of Groomed/Un-Groomed Antennae Extracts
Phil Duran, Isaac Jeantete, Brenda Porta Linnell (Ph.D)
Northern New Mexico College
Department of BCES: Chemistry
Abstract
Results and Analysis
Results and Analysis
Conclusions
The species Blaberus discoidalis and Perpiplaneta Americana cockroaches were prevented from grooming their antennae, so that they could not remove excess hydrocarbons. These hydrocarbon debris impede the insects olfactory receptors an modify their behavior.(1) Antennae extracts were analyzed by UV Spectrometry and Gas Chromatography to identify substrates.
UV spectra shows the maximum absorptions for ungroomed roaches shift to the right in both specimens, indicating the presence of the same molecular effect.
Data from Gas chromatography, supports the hypothesis of stearic acid being present in the ungroomed antennae cockroach extract. No geranyl acetate was detected in either extract.
Ultra-Violet Spectra, Max absorption Wavelength (nm)
Gas Chromatographs
Big Cockroach Groomed
Big Cockroach Controlled
Data Collection and Methods
Cockroaches were pacified with an ice water bath. Super glue sealed their mouths shut. Small pipettes were placed around the antennae, to prevent the roaches from using their front forelegs from interacting with their antennae. The roaches were anesthetized by refrigeration, their antennas removed with scissors, and extracted with 4ml hexane into four separate vials. Hexane evaporated over time, leaving behind crystal structures. These structures were later tested using UV Spectrometry and Gas Chromatography.
Future Work
To develop a method for quantification of stearic acid, by Gas chromatography is needed.
Standards of other hydrocarbons will also be tested in new specimens
Small Cockroach Groomed
Small Cockroach Controlled
Hypotheses
Stearic Acid
UV spectra Analysis
Groomed cockroaches gave an extract with less absorbance than the Ungroomed cockroaches. More absorption means that there is more particles to take in the UV light. In this case hydrocarbons.
Stearic acid will be the main hydrocarbon in the antennae extract from surface. Geranyl acetate may also be evident from air. Stearic acid is a common fatty acid found on many lifeforms, when they are unable to perform hygienic practices on themselves.
References
(1)Böröczky, Katalin, et al. "Insects groom their antennae to enhance olfactory acuity." Proceedings of the national Academy of Sciences (2013):
Acknowledgements
GC chromatograph Analysis
The peak identified as stearic acid was observed with more intensity in ungroomed cockroaches. This confirms the presence of the hydrocarbon
Catherine Pacheco
Dr. Ulises Ricoy and Aspen Lowance for their assistance
Stearic Acid
Geranyl acetate