as far as experienced by colleagues of mine working on moths, the better way to kill moths is the freezer cold. Chemicals are always problematic with moth killing due to colour preservation and muscular rigidity

it depends if You dont have any freezer and You are in field the best option is acetate chloroform is the worst option from all of them ...but if You are using light traps for example to these traps I use the chloroform occasionally 

If you are joining an expedition to an "exotic" country [= country which is not your own!] we use to put the moths in glass (or plastic tubes) and submerge these in boiling water (everybody needs some thee doesn't he?). Do not just throw  the tubes into the boiling water but hold the lid outside the water and wait until the insect is dead. For microlepidoptera in glass jars, this takes only 5 seconds, for larger moths it takes up to 30 seconds, but with this method there is no need to transport chemicals on airplanes, and the moths remain very flexible after dying.

We use ethyl acetate. it give satisfactory results. 

We use 95% ethanol.

Thanks to all of you for sharing your experiences. I have used chloroform, ethanol and ethyl acetate. Ethanol is slow but chloroform and ethyl acetate is quick in response. when I used ethyl acetate, the abdomen of the moths become very soft and sometimes fall off during setting, WHY?

You may not be using it in a right way. Talk a wide mouth glass bottle. Fix cotton on the inner side of the lid of the bottle with the help of some glue. Then pour ethyl acetate on the cotton and make the cotton little less from saturated. now close the bottle and keep it for 5 min. It will be charged for killing. Now add the moth in it to kill. Keep the moth in that bottle until it seems to be dead. Then take it out from the bottle and pin. 

Abdomens may fall due to mis-handling. We have been using ethyl acetate with the above procedure and we never encountered such problem. Hope it will help.

Thanks Deepika.

First let me begin by stating, I have used these two chemicals, l and experimented with dozens of other chemicals, hexane, carbon tetrachloride, gasoline, naptha, chlorine, benzene, ether, and numerous others over the past 50 years for the purpose of dispatching insect and especially moth specimens.  I operate many dozens of moth traps every day and night of every year, for the past 46 years.  I have never experienced an abdomen falling off of a specimen while on a setting board, and I have personally spread nearly 1,000,000 specimens in the past 56 years. Regarding chloroform, I experimented with two gallons of this and found it not to be a good chemical for killing moths so that they were in good condition to later spread.  Ethyl acetate is much better for killing moths, but can discolor the specimens if too much is used or exposed to long to the specimens. It is a poor choice for a killing agent for delicate moths or green colored specimens.  It kills slowly if used in a killing jar, but works well if is sparingly injected into larger moth thoraxes. I have used Ethyl acetate for injecting large moths and beetles for over 50 years. I have even purchased this chemical in 75 gallon and 5 gallon drums for this purpose or to use in my traps long ago.  

Neither Chloroform nor Ethyl Acetate are your best options to obtain the best quality specimens in the end.  The absolute best chemical to kill all insect specimens of any order is Cyanide, either sodium cyanide or potassium cyanide.  I have used sodium cyanide every day for the past 41 years.  In fact, I have about 400 insect traps of various types and I purchase sodium cyanide in 50 or 100 kg drums. There is no better insect killing agent available in the world. But one cannot bring this chemical into a building or one;s home or vehicle.  It is a dangerous chemical unless always used with caution, and must always be kept out of doors, even in containers or jars.  One accident could be your last accident. 

Dear All,

Vernon is right. The best killing agents are cyanides. Insect collectors of the 19th and early 20th centuries used mostly these agents. I remember the case of Kálmán Kittenberger who was the collector of the Hungarian National History Museum in Africa. He was a famous hunter but dealt also with insects. Once he was attacked by a lion and lost one of his fingers. In order to show his bosses in Budapest how much time he devoted to insects he sent his finger in a glass jar filled with insects. The potassium cyanide conserved also his finger and the discoloration of the finger proved the permanent use of cyanide.

I must also add that since I use quite a lot of sodium cyanide, the cost not only to purchase the chemical but also the man-hours involved in the use of this chemical is a major consideration.  I can put into my stationary traps 2-4 pounds of sodium cyanide at the beginning of the year, and not have to add additional chemical until a year later.  Where using Ethyl acetate, I would have to spend several hours each day of the year adding new EA to my killing chamber on my traps. One day or 365 days of labor - you decide.

The answers are really interesting, but most of them do not address his question: Does or does not ethyl acetate damage insects?

I have used ethyl acetate to kill moths, and I have never found that problem at all. Maybe you're using too much of it. It should not soak the specimen. How long do you leave the insects in the jar? Does it happen with big moths only, or with small specimens as well? If it happens with big specimens, it could be they contain too much water and if the weather is too humid, they could rot...

Ok Ricardo, the answer is no Ethyl Acetate (EA) is not a very good chemical dispatcher of some orders of insect specimens.  Use too much on adult Lepidoptera and it can make specimens useless for the keeping of good quality specimens.  It can permanently discolor and stain adult Lepidoptera.  Using Ethyl acetate to dispatch (kill) coleoptera,  and it works well for most specimens in this insect order  

But, with trial and error and practice it can be used for any insect orders.  I have used Ethyl acetate to inject large moths and large beetles via a hypodermic syringe.  I recommend using the small gauge, long needle, especially insulin syringes, though, I have used thousands of all types of hypodermic syringes, both plastic and glass.  The one problem is that using a disposable plastic hypodermic syringe with EA is the chemical will swell the rubber plunger and the syringe has to be discarded daily.  For many decades I used reusable all-glass syringes (with glass plungers) when using  EA.  If you start using cyanide, you will never again use anything else to dispatch insect specimens.  You will attain the highest quality of Lepidoptera specimens only with cyanide. Pasted here is a photo example of about 80 wild captured sesiid moths in one pheromone trap using cyanide as a killing agent.  Collecting (dispatching) all these high quality specimens as depicted here would be impossible using EA or any other chemical except cyanide. Dispatching these specimens using EA would make the specimens absolutely worthless and devoid of all scales and many lost legs, most not even recognizable to species or even genus.

Ricardo, I left the specimen for about 2-3 hours depending on size of the moths (larger moths takes longer time). The problem is face only to the larger specimens. and as Vernon mention the specimen loss scales and sometimes its become worthless. The used of EA is not effective.