Path: utzoo!attcan!uunet!husc6!mailrus!cwjcc!gatech!mcnc!ecsvax!hes
From: hes@ecsvax.uncecs.edu (Henry Schaffer)
Newsgroups: sci.bio
Subject: Re: Fruit Flys
Summary: aspiration, etc. and fruit fly culture
Message-ID: <5823@ecsvax.uncecs.edu>
Date: 13 Nov 88 01:22:27 GMT
References: <8648@gryphon.COM>
Organization: NC State Univ.
Lines: 42


  First suggestion is that you visit someone who raises fruit
flies (Drosophila.)  There is much that is easier to see than to
have described in writing.  While raising the flies on mashed
fermenting fruit can work, it is somewhat harder to handle than
when solid media is used.  The flies are attracted to the
fermenting fruit - and the fermentation is particularly attractive.
(to flies, that is.)

  I suggest that aspiration (by mouth) is a fairly efficient way
of collecting them.  Let me see if I can describe the apparatus -
Take a small bottle (1/2 pint or less) with a sturdy top, e.g. a
cork or rubber stopper.  Pierce it with two holes to take glass
tubing.  At the outside of the bottle connect a length of rubber
tubing to each glass tubing and then end with another length of
glass tubing.  One of these is perhaps 8" long and used to collect
the flies, and the other is shorter, and you place it in your 
mouth and suck on it to collect flies.  On the inside of the bottle
side of the cork, the glass tubing going to the fly collecting end
is long enough to reach close to the bottle bottom.  The other
tubing is shorter and its end is covered with cheese cloth (to
keep flies and other stuff from going into your mouth.)

  (All glass tubing ends should be flame polished for safety
reasons.  Also the collecting end works better if it is cut at
an angle.)

  Put the cork on the bottle, the mouth piece in your mouth, and
the collecting end through a hole in the culture container top
(which can normally be closed with a tuft of absorbent cotton)
Then put the end of the glass tubing near a fly or group of flies
and such sharply and "vacuum" them up.  You end up with the flies
in a dry clean bottle.  (The bottle can also be a vial, and ones
about the size of a shotgun shell - no smaller than 16 ga. :-)
work well.)

  With solid food, the whole culture container can be inverted
over an empty bottle and the two of them together tapped on a
table, knocking the flies into the lower bottle.  However, that
is another topic.

--henry schaffer