4. • Collembolan: Onychiurus emits a general glow from the whole
body
• Hemiptera: Fulgora the light organ is in the head. The light organs
are generally derived from the fat body
• Diptera: In glow worm fly Arachnocampa they are formed from the
enlarged distal ends of the Malpighian tubules.
• Coleoptera:In male Photuris there is a pair of light organs in the
ventral region of each of the sixth and seventh abdominal segments.
In the female the organs are smaller and often only occur in one
segment.
• The larvae have a pair of small light organs in segment eight, but
these are lost at metamorphosis when the adult structures form.
• Phengodidae:Larvae and females of railroad worms have 11 pairs of
dorso-lateral light organs on the thorax and abdomen and another on
the head.
4
6. Light is produced in organelles called peroxisomes,
noted as centers for enzymatic oxidation reactions.
A two-stage reaction occurs within these peroxisomes.
First, adenylation of substrate luciferin (which is
dependent on the presence of magnesium-ATP) occurs
under the catalytic action of luciferase.
The subsequent oxygenation of luciferyl adenylate by
molecular oxygen results in the emission of light and
the production of oxyluciferin.
6
8. • Coleoptera: In Photinus and Lampyris the
light produced is yellow-green in color(520–
650 nm).
• Phrixothrix larval and adult female, thorax
and abdomen produce green to orange light
(530–590 nm). That on the head produces red
light(580 nm to over 700 nm)
• Diptera: Arachnocampa produces blue-
green
• Hemiptera: Fulgora produces white light. 8
9. • Dorsal Unpaired Median (DUM) release
octopamine.
• DUM cells present in the last two abdominal
ganglia respectively, which release octopamine.
• The axons from these cells divide to send
symmetrical branches to the lanterns on each side.
• In most adult fireflies the axons terminate on the
tracheal end cells,
• In larvae, where there are no end cells, they
innervate the photocytes directly.
9
10. • In adult Photuris, light production appears to be regulated
by the availability of oxygen.
• As the DUM neurons terminate on the tracheal end cells.
• Neural activity causes a change in these cells, facilitating
the flow of oxygen to the photocytes.
• This implies that the oxygen supply to the photocytes is
closely regulated.
• It is believed that hydrogen peroxide plays a role in this
regulation.
• The peroxisome oxidases use oxygen arriving at open
mitochondria to create hydrogen peroxide that builds up
explosively due to the shutdown of the catalase.
• This completes the oxidation reaction and triggers the flash.
10
11. • The precise temporal control of firefly flashing is understood to
be regulated by nitric oxide (NO).
• NO synthase is localized near synaptic terminals within the firefly
lantern.
• Measurements indicate that externally added NO stimulates
bioluminescence production while the addition of NO scavengers
inhibits light production.
• Furthermore, NO is known to control respiration by photocyte
mitochondria reversibly.
• The proposed mechanism comprises neural stimulation resulting in
the transient release of NO that diffuses into the periphery of
adjacent photocytes.
• This inhibits mitochondrial respiration and permits oxygen to
diffuse into the photocyte, which holds the bioluminescence
reactants.
11
12. A firefly's photic organ is functional throughout pupation
and glows when the pupa is disturbed. Credit: ARMIN
MOCZEK AND MATTHEW STANSBURY
12
14. A most recognised classification compiling five
categories of sound producing mechanisms is as
follows:
1) Vibration and Tremulation
2) Percussion
3) Stridulation
4) Click Mechanisms
5) Air Expulsion
Ewing (1989)14
15. Sound emissions which result from:
Vibrations
Most usually oscillations of the abdomen
Either dorso-ventrally or laterally, and/or by the wings.
Tremulation
Sound production transmitted through the legs to the
substrate on which the insect is walking or standing.
(Claridge, 2005)
15
19. Sounds produced by frictional mechanisms,
involving the movements of two specialized
insect body parts against each other in a regular
patterned manner.
(Claridge, 2005)
19
23. These sounds rely on the deformation of a
modified area of cuticle, generally by contraction
and relaxation of special musculature within the
insect body.
This movement results in a succession of clicks
which may be repeated quickly in distinctive
patterns.
(Claridge, 2005)
23
26. Body temperature is the result of a balance between rate heat gain and
heat loss. So two ways to regulated an elevated body temperature.
Regulation of heat gain
Regulation of heat loss
Levels at which heat gain and heat loss occur
Physiological mechanism: Regulation of heat production and heat
transfer within the body
Behavioral mechanism: regulation of heat exchange between the
body and the external environment.
A survey on 40 species of Lepidoptera showed that the preferred
temperature fur butterflies to fly is 30-40 C. the flight temperautere for
butterflies is very similar to many other insects.
26
27. Regulation of heat gain :
One mean of heat gain for thermoregulation is by metabolic generation of heat which is
mainly produced by thoracic flight muscles during flight and preflight warm up.
During preflight warm-up antagonistic muscles are activated simultaneously. That
makes little wing movement but produces heat. This phenomenon is present in
majority of insect taxa including Lepidoptera Coleoptera and Diptera etc.
During flight heat is produced by rapid contraction of flight muscles. Different
insects can increase their body temperature during flight ranging from 3-20 C.
Abdominal temperature is regulated by circulation of hemolymph.
Thoracic temperature is regulated more precisely as compared to abdominal
temperature.
Hemolymph flow in the wing veins also effect the heat transfer between thorax and
wings and contribute thoracic heating.
27
28. Regulation of heat loss:
At high temperatures heart beat is high and heat generated
through flight muscles is transferred to the hemolymph and
then from thorax to the abdomen that is poorly insulated.
At low air temperatures heart beat is low and hemolymph
flow is also slow that transfers small amount of heat to the
abdomen. This provides a rather precise way of regulating heat
loss and thoracic temperature.
28
30. Male crickets chose cracks in the ground at a
temperature where the frequency and intensity of their
calling songs were maximized.
• Optimize attractive characteristics (e.g., chirp rate) of
calling songs to mates.
Locust nymphs deprived of protein or carbohydrate
and then fed a meal subsequently chose different
temperatures.
• Maximize the assimilation of the nutrient that
addresses their nutritional imbalance.
30
31. Butterflies changed orientation of their wings to
reflect solar radiation onto their thorax.
• Attain body temperatures necessary for flight.
Adult water striders submerged themselves
underwater when water temperature was higher
than ambient air temperature.
• Increase the rate of gonad maturation and egg
production.
31
32. Flies at warm locations were mostly active in the
evening.
• Avoid exposure of eggs to high daytime
temperatures soon after oviposition.
32
33. Moths beat and vibrated their wings pre-flight.
• Warm up flight muscles to temperatures
necessary to initiate flight.
Hornet workers beat their wings at the nest
entrance when temperature increased.
• Ventilate the nest to prevent it from
overheating.
33
