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Procedure
Cut with scalpel the lateral connexive (Fig. 1, reference 16),
placing the oblique sheet to the same cutting only the dorsal
cuticle. In the posterior extremity of the insect, cut a bit
on top, without breaking the genital armor and the rectum.
Lift the tergites by carefully unsticking it with the tweezers and
scalpel. Cut when thorax has been reached. By doing
this, the dorsal vessel, greasy tissue and tracheas will be exposed
(Fig. 7 B).
Use tweezers to remove the greasy tissue and tracheas (be very
careful, the greasy tissue can easily be confused with the Malpighi
tubules and reproductive organs).
Cut the dorsal vessel without tearing it off (the anterior extremity
must stay intact). Move the digestive tube and observe the
stomach, intestine, Malpighi tubules, rectal ampulla and rectum
(Fig. 8 A). Use scalpel to cut across the thorax pleurae.
Lift the tergites with the tweezers by cutting the fragmas with the
scalpel and separating the muscles. Observe the thorax, the
esophagus, the salivary glands and its ducts (Fig. 8 A and B).
Use two tweezers to take the extremities of the digestive tube
(rectum and esophagus) and remove it, being careful not to spill the
contents in the work zone (if this were to happen, wash the area
affected with great quantities of physiologic solution).
Observe the genitalia (Figs. 9, 10, and 11).
Switch the physiologic solution for 70% alcohol. The 70%
alcohol acts as a fixer and allows for a better look at the nervous
system.
By moving the genitals a bit, you can see the abdominal nerves and
its ramifications (Fig. 12). Remove the muscles from thorax
(very carefully) and observe the ganglions and its nerves (Fig. 12).
Cut the head cuticle laterally (being careful not to break the neck
area) across the yes and cut in front of the eyes in a transversal
way in relation to the head. Lift with tweezers and unstick
the muscles with the scalpel. You will see the brain and the
cardiac bodies exposed (in one end of the aorta) and the
subesophageal ganglion (Fig. 7A and 12).
If necessary, for better viewing of the nervous tissues, you may die
it prior to placing it in alcohol. This may be done by placing
some blue metilene drops inside the insect's body. Leave it to
die for a few minutes and then wash with plenty of physiologic
solution to eliminate the excess die. After that, place it in
70% alcohol to continue the work. The die will be washed
slowly with the alcohol.
Recipes
Physiologic solution
for insets (modified from Case, 1957).
Base Solution:
-1000 ml distilled
water.
-7.5 g NaCl
-0.14 g NaHCO3
-0.35 g KCl
-0.21 g CaCl2
-2.5 g glucose
take to pH 7.0
Buffer:
-A: 0.15 molar
solution KH2PO4
-B: 0.15 molar
solution Na2HPO4
To make buffer, mix 19
volumes of A + 31 volumes of B.
Physiologic Solution =
10 volumes of base solution + 1 volume of buffer
Solution of Blue
metilene:
-Distilled water, 50
ml
-Sodium Borate
(Borax), 0.5 g
-Blue metilene, 0.5 g
-Mix and filter.
Bibliography
- Case, R (1957).
Differentiation of the effects of pH and CO on the spiracular
function of insects. J. Cell. Comp. Physiology. 49. 103-113.
- Insausti, T. C.
(1994). Nervous system of Triatoma infestans.
Journal of Morphology 221: 343-359.
- Ramirez Perez, J.
(1969). Estudios sobre la anatomia de Rhodnius prolixus.
Rev. Ven. de Sanidad y Asist. Social XXXIV: (1) and (2).
- Del Ponte, E.
(1921). Contribucion al estudio del gen. Triatoma
Lap. Primera parte. Anatomia interna. Rev. Inst.
Bact. Dept. Nac. Higiene, Buenos Aires, vol. 3, pp. 133-196, 40 pls.
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