Mounting of larvae (Image).
1) Microscope slides must
be cleaned and labeled as described above.
2) A drop of 75% alcohol is
placed on a cleaned microscope slide in order to dissect the larva.
With two dissecting needles, the head and the abdomen in the seventh
segment are cut. The body must be placed into a Petri box with
75% alcohol while the head is clarified.
3) The head must be macerated
or clarified in order to clearly observe its internal structures.
To get this, the head have to be placed into a vial with 5% KOH
which is warmed with boiling water for 4-5 minutes. After this
time, the head is checked for tissues by using a microscope. If
tissues are still present, the KOH must be removed by putting
the head into a Petri box washing it twice with 75% alcohol for
5 minutes. After the washing, the head is transferred into a vial
with lactic acid, which is placed into boiling water. Every 5
minutes, the head is checked for tissues by using a microscope.
If tissues still remain, the clarification with lactic acid must
continue. To determine if the clarification is done, the head
is put into isopropyl alcohol for 2 or 3 minutes. If there are
tissues, they will become white. Once the head is clarified, it
is placed into a Petri box with 75% alcohol for 5 minutes.
4) The head and the rest of
the body are transferred into a Petri box with isopropyl alcohol
for 5 minutes.
5) The head, the thorax-abdomen
and the anal segment are put in a drop of Euparal, which was on
a previously cleaned and labeled micro slide. The dorsal sides
of these structures must be faced up, putting the head slightly
up and left of the thorax, and the anal segment slightly down
and to the right of the abdomen. This location of the structures
will equilibrate the cover glass if the larva is thick.
6) To dry and take care of
the mounted slide, the fourth step of the exuvia mounting given
above should be followed.
