Chemical ecology Flashcards
Identification of volatile source
- what is the source?
- what behaviour does it cause?
- prove that semiochemical are involved
- How do you exploit this?
Olfactometers
Contain airflow
good for rapid screening of odours
groups of insects used
insects should never be used more than once
needs to be designed for each arthropod type
The Y tube
mosquito ha to decide to go left or right at the junction
doesn’t work well for anopheles or tsetse
wind tunnel better for anopheles
Wind tunnel
can video flight path of mosquito
important fro trap development
Still air olfactometer
for walking insects eg. bed bugs
infrared camera - measures how long the stay in each area
Servosphere
treadmill for walking insects
airflow over insects
Collection of volatiles
can use solvent extraction
or Air entrainment - put poop in a bag and collect into a charcoal filter
Host volatiles - microbacteria
bacteria convert sweat into carbolic acid and also produce Co2
Human odour is genetically dtermined by MHC genes
Does infection alter attractiveness to vectors
yes - disease can cause changes in individuals odour profile
Analysis of volatiles
can use Electroantennography
or single sensillum recordings
or gas chromatography
Electroantennography
attach microelectrodes to antennae
records response of all olfactory receptor neurones on antennae
tells you if insect can detect individual chemicals
single sensillum recordings
Microelectrodes inserted into sensillum and recording made from ORNs
one electrode in sensillum and reference electrode in lymph or eye of insect
gas chromatography
liquid sample injected into gas chamber and vapourised
chemicals separated in relation to weight
accurate quantification of chemicals
in human odour 400-500 volatile chemicals