Subject: Re: substitute for ethyl acetate???

From: Reed Watkins <[email-masked]>
Date: Wed, 3 Jul 1996 00:09:51 -0400

In response to Orville Marti, who posted:

>Has anyone had experience with an effective substitute for ethyl acetate--
>something that might be easily obtained from a drugstore?

Some people use ammonia in various forms.  Relative safety at modest
concentrations, particularly if children are involved, is one of its
favorable attributes.  However, at these modest concentrations, its relative
lack of strong "knock down" power is a weak point.  For this reason, it has
been my experience that it works best for "micros" and other small bodied
lepidoptera, but not so well for large bodied specimens such as sphingids
and the larger noctuids and saturniids.  Another disadvantage is that green
colored specimens such as some geometrids tend to fade if exposed to ammonia
gas for too long.

One form is liquid solution in water.  A weak solution can be bought at the
grocery store as a household cleaner, but this is really too weak to be
useful.  A drop of two of a stronger solution adsorbed in cotton or tissue
in a small vial is very effective on micros.  I and some others collect
micros in individual vials, keep them alive but cool until convenient (eg.
the next morning) and then kill them this way and spread immediately.  This
prevents the troublesome drying out that can be a severe problem with small
specimens - which have a large surface to volume ratio.

I find another generally useful form to be ammonium carbonate, a dry, white
powder which is convenient for killing jars, as described by Mike and Todd
Gilligan in the December 1990 issue of The Ohio Lepidopterist newsletter -
Volume 12, No. 4.  These jars last a long time between recharges.  Ammonium
carbonate spontaneously decomposes at normal ambient temperatures to release
the gases ammonia, carbon dioxide, and water.

        (NH4)2 CO3 <--> 2NH3 + CO2 + H2O

This reversible, equilibrium reaction produces more gas at higher
temperatures and less at lower temperatures.  Thus, under cool conditions
(eg. less than roughly 50 degrees F) it becomes less effective.  Note,
however, that the water vapor released by the reaction will also help
prevent specimens from drying out.  Specimens left in an ammonium carbonate
"dump jar" overnight are kept in good condition for spreading.  This benefit
comes with a drawback, however.  Care must be taken to avoid sudden cooling
of jars containing specimens since they may "sweat" on the inside as the
water vapor condenses.

These methods are not cure-alls, but are good for some people in some
situations.

---

From: MS SALLY O LEVINSON <[email-masked]>
Date: Wed, 3 Jul 1996 10:10:34 -0500

Sometimes, instead of a killing jar, I freeze specimens.  It usually
takes at least an hour.  And it didn't work on the ants.--Sally