Charles

   I am not sure how big is your larvae but you can try this method preparing a live larva GC-EAD. You can cut off the sharp tip of an approriate eppendorf tube and carefully coax the larva for its head+antennae to emerge at the open end of the eppendort tip. Then use some cotton wool to stuff the remaining space within the eppendorf tube so order the larvae could not retract its head/body back into the tube. If you manage to do it nicely, you can test a host of volatiles against the same antennae!

Have fun with your insect!

Hi Charles,

It depends of course on the size. Single cell recording might be the best technique since you do not have a 'tube' shaped antenna. 

Also keeping alive a larvae equiped with electrodes as long as a GC run could be problematic.

Denis Thiéry

Hi Charles,

In my opinion , first you have look the chemosensory receptors location at larval antennae whether are they distributed  evenly throughout the antennae or bunched only on some segments or top. Because if your larvae has all the chemoreceptors on top of the antenna , then probably your electrolyte solution will cover them to interfere the response. To avoid this issue may you decide to follow the procedure as mentioned by Suk Ling Wee and try to use the electrode as pointed out this article

Atle Wibe, 2004. Journal of Insect Physiology 50 (2004) 497–503

(www.elsevier.com/locate/jinsphys) How the choice of method influence on the results

in electrophysiological studies of insect olfaction.

All the Best

Karthi

Hi Charles

Back to your antenna size (length) and shape which are key points. For EAG you need to cover the tip of the antenna but still keeping exposed the pores to the air flow. In flies with very short antennae, large electrodes can be applied covering antennal surface. Possibly some description of your antenna (or pictures) would help.

Denis 

thanks everyone for your input. The larvae are 6th- 8th instars.

@Suk Lee and @Dennis,  I have used cut eppendorf tubes to restrain them but it wasn't successful. I need to incorporate cotton wool because in my initial attempts dint use it. 

@Karthi will go through the paper as per your suggestion.

Once again thank you guyz.

Charles,

Which larva you are using for your study? Does they contain olfactory sensilla to perceive airborne volatiles in the GC effluent?

This paper on Spodoptera litura by FM. Poll et al. 2014 may help.

@Seenivasagan. I'm using wax moth larvae.

 Thank you very much for sharing the paper, it actually makes it easier connecting  a thin silver electrode through to the antennae.

I tried using cotton wool in eppendorf tubes with chopped tip but it din't work out because the larvae could still manage to retract antenna.

Thanks everyone, I will share the option that will work out.