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
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.
Ultra-Violet Spectra, Max
absorption Wavelength (nm)
Gas Chromatographs
Big Cockroach Groomed
S1 Ungroomed Maximum Absorption
261.2
0.22
0.21
0.2
0.19
0.18
0.17
0.16
250.5
255.5
260.5
265.5
270.5
275.5
Big Cockroach Controlled
C1 Groomed Maximum Absorption
252.8
Conclusions
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.
0.39
Data Collection and Methods
0.38
0.37
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.
0.36
Future Work
0.35
0.34
0.33
0.32
246.9
248.9
250.9
252.9
254.9
256.9
258.9
260.9
262.9
264.9
Small Cockroach Groomed
S2 Ungroomed Maximum Absorption
263.1
0.195
0.19
0.185
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
0.18
0.175
0.17
0.165
249
254
259
264
269
274
Small Cockroach Controlled
C2 Groomed Maximum Absorption
261.2
0.2
0.195
0.19
0.185
0.18
0.175
0.17
0.165
0.16
0.155
Hypotheses
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.
Stearic Acid
Geranyl acetate
0.15
252.1
257.1
262.1
267.1
272.1
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.
277.1
282.1
Stearic Acid
References
(1)Böröczky, Katalin, et al. "Insects
groom their antennae to enhance
olfactory acuity." Proceedings of the
national Academy of Sciences
110.9 (2013): 3615-3620.
GC chromatograph Analysis
• The peak identified as stearic
acid was observed with more
intensity in ungroomed
cockroaches. This confirms the
presence of the hydrocarbon
Acknowledgements
 Catherine Pacheco
 Dr. Ulises Ricoy and Aspen
Lowance for their
assistance