Monday, November 7, 2011

Relaxing insects.

No, this isn't about the calming powers of butterflies. The Nature Plus Beetle Blog has an excellent post of relaxing beetles using a kitchen steamer. Usually, entomologists use these glass hydration chambers, but this is an excellent idea for hard bodied insects. I especially like the use of thyme oil as an anti-fungal. 10 minutes apparently is all it takes to hydrate a batch of beetles to the point where they won't be damaged in mounting. It's also a good explanation of point mounting.

I would really like to see a post by someone on removing insects from alcohol to be pinned. I've experimented with xylene and 100% ethanol, but neither of these is satisfactory for Diptera or Trichoptera. I've heard good things about HMDS (hexamethyldisilazane), but I've never been able to get my hands on any to try it out.

4 comments:

naturalhistoryinsuburbia said...

Kai, we use HMDS at the Lyman Entomological museum to dry all of our small diptera (i.e acalyptrates and nematocerans) and works really well. The only special equipment needed is a fumehood as the chemical is incredibly volatile and has an associated health hazard (can't remember exactly what). More info here: http://www.cdfa.ca.gov/plant/ppd/entomology/HMDS.html

For larger diptera/insects you can use a progression through 100% EtOH and then into 50/50 ethyl acetate and EtOH and a final soak in 100% Ethyl actete (similar to this method http://pubs.esc-sec.ca/doi/abs/10.4039/Ent9869-1).
Hope that helps.

Chris Borkent

ZL "Kai" Burington said...

Thanks Chris! I've heard that all the water has to be removed from the specimens prior to soaking because it makes ammonium gas. This is probably in addition to the other health hazards. Dr. Peter Adler has told me that it works so well, you can run a honey bee through it and the hair comes out unmatted. I'd love to try it sometime, but given I don't have a fume hood right now I just can't risk it.

~Kai ZL Burington

Morgan Jackson said...

At the University of Guelph Insect Collection we use a sequential ethyl acetate bath for the medium-large soft bodied insects (Diptera, aquatics, etc) and Critical Point Drying (CPD) for the small and really small things. The CPD uses liquid carbon dioxide held in a high pressure chamber to force the 100% ethanol out of the specimen in a flash, leaving the specimens in a near perfect state (haven't tried it with a honey bee, so no clue how the hairs would turn out in comparison). Takes about a week to transfer the specimens through the ethanol ladder, but we can dry 16 vials of insects/CPD run, so it's pretty efficient.

ZL "Kai" Burington said...

Critical point drying sounds awesome, but also really expensive, Morgan. I'd love to have a system I could use in a small lab with a fume hood.