6 February 2017
A killing jar is a container that has chemical substance (or killing agent) that used to kill collected insects in the field to prevent any further damage to specimens. As I don’t collect any soft-bodied insects, I don’t ever use killing jar up until now. I usually kill my collections by dumping them into the alcohol (or sometimes injecting small amount of alcohol into the abdomen) or freeze them after I get back home. These days, I started to collect some Lepidopterans so I started to feel the needs of killing jars.
There are many chemical used in killing jars, like Sodium Cyanide, Ethyl Acetate, Ammonium Carbonate, etc. I have an experience of using Sodium Cyanide in my collection trip with Vernon A. Brou Jr. of Louisiana Lepidoptera Survey (Abita Springs, Louisiana). It is most amazing killing agent. It can kill moths in couple of seconds. However, it is not something you can get in nowadays. It is banned to be sold as it is very, very toxic substance. As I’m not affiliated to any institution, I doubt I can get a hand on it at all.
Ethyl acetate? that’s something I can easily obtain, but it is horrible. It takes forever to kill specimens. I have an experience of using it in my freshmen year in college, at class. I only used it once and left it on my desk until the last day of semester.
I know couple of colleagues who use Ammonium, but they weren’t aware of what kind of Ammonium they are using. So I had to go look through and found Dr. Todd M. Gilligan at the Colorado State University and USDA. According to him, the Ammonium Carbonate is what he use all the time for moth collecting. Ammonium Carbonate is very good one for moth collecting as it does not dehydrate specimens even when stored for long time. This is good point as small sized Leps are difficult to be spreaded once dehydrated (even if rehydrated). Ethyl Acetate does dehydrate specimens when stored for long time, and Sodium Cyanide sometimes, depending on species, can discolor the specimens. Dr. Todd A. Gilligan suggested me to use an old sock to store the Ammonium Carbonate as it can damage the plaster (usually used in killing jar).
It was rather a long intro, but…
I made a purchase of Sodium Carbonate, from The Science Shop online as they were selling 500g in fair price compare to the others, and they even ship items for free with USPS 3-Days Priority. EXCEPT… they sent this toxic chemical substance in non-airtight container! I better find one that can SAFELY store this…
It is amazing! I tried right away on night. Moth got paralyzed after about 10 seconds. I think it takes some time to completely kill specimens, but paralyzing is definitely enough to prevent any damage from their own movements. As a sock didn’t stayed tight on bottom of killing jar, I better update things for easy works. Following picture is moths paralyzed/killed by the Ammonium Carbonate, and they are pretty clean and neat condition.