Hi Melina, there are two related questions and answers in the two links provided. I'm also planning to store an arthropod in RNAlater and wonder whether the RNAlater will penetrate the cuticle fast enough to preserve the RNA.

https://www.researchgate.net/post/Can_we_flash_freeze_insects_in_liquid_N_and_then_put_them_in_RNAlater_for_RNA_preservation

https://www.researchgate.net/post/Will_RNAlater_work_with_small_insect_with_very_hard_exoskeleton

¡Hi Pablo! Thank you so much for your answer. I'm still hesitating abut the correct way to preserve the insect so we are going to try a pilot experiment to see if RNAlater actually works. I'll let you know of the result and the difference of the RNA quality in comparison with TRIzol storage.

I have had my doubts on the quick penetration on large insects like kissing bugs.  I've tried it with ticks. Sometimes it worked but I did have some failures.  I think in your favor is the fact that the Trypanosoma are still viable for a long time in the feces so even relatively slow penetration should allow them to be preserved.

Hello Will

For what I've read the main issue is that the RNAlater solution does not kill the insect very quickly so many stress-related genes express in response to the situation. And in my case this is a problem because I want to see differential expression. Besides that, the fact that the RNAlater may not penetrate the insect fast enough is also a problem because RNA tend to degradate very quickly.

If you are still looking for solutions, I know that honey bees can be flash-frozen in liquid nitrogen, then stored in pre-cooled RNAlater. We did segment the bees prior to storage, but this was still storing whole abdomens in solution. The eventual usage was for RT-qPCR, so the pilot study may still be useful for determining if your chosen platform can detect issues.