v mary floret phd 1st year entomology

1. Research Supervisor and
Convener, Chairman
Dr. S. Manickavasagam
Professor and Head
Department of Entomology
Advisory committee
members
Dr. Arivudainambi Professor,
Department of Entomology
(Intra Expert Member)
Dr. A. Shakila, Professor,
Department of Horticulture
(Inter Expert Member)
Research scholar
V.Mary floret

2. 1) What is locust
2) Phase change, feature of locust biology
3) Epigenetics & locust life phase transitions
4) Role of serotonin
5) Role of octopamine
6) Role of Adepokinetic hormone
7) What is migration & Physiology?
8) Carbohydrate pathway
9) Lipid pathway
10) What fuel used for flight?
11) Energy reserve during flight of the desert locust
12) Flight muscle metabolism
13) Glycolosis ?.
10/23/2019 2All about locust

3. What are locusts?
Locusts are any of a group of insects that belongs to the family
Acrididae of order Orthoptera.
Locusts are commonly known as short-horned grasshoppers.
They often increase greatly in numbers and migrate long distances
in destructive swarms.
They are distributed worldwide.
10/23/2019 3All about locust

4. SOME COMMON LOCUSTS ARE
American locust: Schistocerca americana
Bombay locust: Nomadacris succincta
Tree locusts: Anacaridium spp.
Red locust: Nomadacris septemfasciata
Migratory locust: Locusta migratoria
Italian locust: Callipta musitalicus
Desert locust: Schistocerca gregaria
Brown locust: Locusta anapardalina
10/23/2019 4All about locust

5. Phase change: the defining feature of
locust biology
Reared alone
Solitary phase
Reared
crowded
Gregarious
phase
Transient phase (Rogers et al., 2010).10/23/2019 5All about locust

6. (Rogers et al., 2010).
10/23/2019 6All about locust

7. life of locust
(Burrows et al., 2011)
10/23/2019 7All about locust

8. EPIGENETICS & PHASE TRANSITIONS
Serotonin
dopamine
GABA
Glutamate
corazonin,
Acetylcholine and
histamine
noradrenaline
Figure 4.13. Changes from solitarious to gregarious behavior occur rapidly and are mediated
by serotonin. Diagrammatic summary of the behavioral gregarization pathway and the role of
serotonin is shown.
Octopamine
10/23/2019 8All about locust

9. Sub:
1) Comparing solitarious and gregarious phases:
morphology, behaviour and physiology
2) Hypothetical model for epigenetic
remodelling in locust phase transitions.
3) Making the switch: initiation of phase
transition
4) Neuroendocrine control of phase transition:
corazonin, juvenile hormone, serotonin and
dopamine
10/23/2019 9All about locust

10. COMPARING SOLITARIOUS AND GREGARIOUS PHASES:
MORPHOLOGY,BEHAVIOUR AND PHYSIOLOGY
 Mechanical stimulation of the
hindlegs, and combined sight
and smell of other locusts.
Gregarisation results in altered
morphology, physiology,
behaviour and colour.
(Pener and Simpson, 2009; Uvarov, 1966).
10/23/2019 10All about locust

11. Body coloration of S. gregaria depends
largely on phase and developmental stage.
•
Solitarious locusts are larger and cryptically coloured; gregarious locusts display
aposematic colours. Males are shown in the gregarious phase as last instar larva (A)
and imago (B), and in the solitarious phase as last instar larva (C) and imago (D).10/23/2019 11All about locust

12. Regions in the midbrain (MBr) include the olfactory antennal lobe (AL) and three neuropils in the mushroom
body: the olfactory primary calyx (pcx), the gustatory accessory calyx (acx), and the multimodal lobes (lb).
The optic lobe (OL) comprises three successive visual neuropils: the lamina (la), the medulla (me), and the
lobula (lo). Absolute total brain size is 27% larger in gregarious locusts. The remaining numbers refer to the
differences in proportions of different brain regions relative to the total brain size. Positive numbers indicate
that a region is disproportionally larger in gregarious locusts than in solitarious locusts
10/23/2019 12All about locust

13. MAKING THE SWITCH: INITIATION OF
PHASE TRANSITION
No of factors involved in Phase transition
of locust1
2
Two distict sensory pathway s are
involved in aggregation behaviour.
3
Cerebral pathway (Visual $ olfactory stimuli
Thoracic pathway (Hind leg Tactile Stimuli
(Ellis, 1959; Simpson et al., 2001).
10/23/2019 13All about locust

14. Hypothetical model for epigenetic
remodelling in locust phase transitions
Eggs may be primed
in the ovary and in the egg pod by
an egg foam factor. When offspring
Also experience crowding, epigenetic
alterations may accumulate that
subsequently lead to morphological
changes and the phenotype of
longterm gregarious locusts.
10/23/2019 14All about locust

15. Neuroendocrine control of phase transition: corazonin,
juvenile hormone, serotonin and dopamine
JH & its analogues induce green body colour in solitarious forms
Dopamine- induce gregarious like behaviour
Corazonin account s for body colour polyphenism, in both
desert and migratory locusts (Tanaka, 2006). It induces a more convex pronotum in isolated
locusts
locustsCorazonin an undecapeptide released from the corpora cardiaca, causes darkening
Serotonin is involved in both the gregarisation and solitarisation decision.
Serotonin displays a peak in the optic lobes (located in the head cavity) shortly after isolation,
while a similar peak is seen in the thoracic ganglia
(Rogers et al., 2004).
10/23/2019 15All about locust

16. Case study
Role of serotonin
When Serotonin was blocked two
times no gregariousness
But when injected, locust turns into G
even in the absence of other locusts
Final chemical natural synthesis of
serotonin enhance gregarization when
locust exposed to tickling stimuli
study says synthesis of serotonin by
this specific stimuli and in turn
changes the behaviour
(Pener and Simpson, 2009).10/23/2019 16All about locust

17. • Although the concentration of several potential neurochemicals differs between
solitarious and gregarious locusts, only serotonin shows a dramatic transient increase
within hours of crowding
(Rogers et al., 2004).
10/23/2019 17All about locust

18. Role of octopamine
*Energy metabolism during flight initiated by
octopamine regulated by Adipokinetic hormone.
*
*Trehalose serve as the major fuel at the onset
of flight.
*Octopamine have several other effects on flight behaviour
@Stimulating interneurons.
@Interneurons are involved in maintaining flight
Pener and Simpson, 2009
10/23/2019 18All about locust

19. Role of Adepokinetic hormone
AKH activates on adenylate cyclase that
increase levels & activate protein kinase.
Protein kinase then phosphorylates activate
lipase that induce release of diacylglycerols from
the triacylglycerols stored in fat body
AKH induce production of lipoprotein carrier
from the fat body that transports these
diacylglycerols through hemolymph to flight
muscles
The metabolism of carbohydrates stored in
flight muscles during lipid mobilization is also
inhibited by AKH so lipid reserves are used
exclusively.
10/23/2019 19All about locust

20. What is Migration ?
Persistent
prolonged
movement
Distinct
departure
and arrival
behavior
Reallocation
of energy in
advance of
migration
10/23/2019 20All about locust

21. What is Migration Physiology?
• Many physiological
changes
• High intensity
exercise Up to 11
days without
stopping to rest!
• Migrants are
extreme endurance
athletes
• Specialized
structure
10/23/2019 21All about locust

22. 3 Metabolic Fuels
Carbohydrate (mostly glucose) is stored
as glycogen in liver and muscle.
Protein has no storage form. It is all
functional (enzymes, transporters,
structural).
Fat is stored as triacylglycerol in adipose
and muscle.
10/23/2019 22All about locust

23. What are Carbohydrates?
• It composed of elements carbon, hydrogen and oxygen.
Key terms:
 Saccharide
 Monosaccharide
 Disaccharide
 Polysaccharide
 Carbohydrates serve as the storage
form of energy Glycogen and trehalose to meet energy demand.
The conversion of carbohydrates in to smaller sugars which get
converted in to energy with the help of enzymes and hormones
is the carbohydrate metabolism.
10/23/2019 23All about locust

24. The function of
carbohydrate in
locust
This enzyme activities provide an estimate relative rates of oxidation of
glucose and fattyacids in the flight muscles.10/23/2019 24All about locust

25. Oxidation of fatty acids provides the energy for
sustainable flight in locust.
Jutsum and Goldworthy
(1976).
30 min
oxidation
carbohydrates.
10/23/2019 25All about locust

26. Lipids
• Def : are organic substances soluble in organic
solvent insoluble in water.
• Classification of lipid:
• Simple lipid
• Complex
• Derived lipid
• Miscelleneous lipid
• Neutral lipid
Fat are stored and transported principally in the form of tri- and
diacylglycerol
Sacktor (1975).10/23/2019 26All about locust

27. fatty acid
pathway
Carnitine Plays major important role in Oxidation of fatty acids
Carnitine requirement more during intial stage of flight at low
temparature
Locust are
maintained 40˚c
are able to oxidise
long chain fatty
acid
10/23/2019 27All about locust

28. What fuel is used during flight?
•
CARBOHYD
RATES protein Fat
Fat
????
10/23/2019 28All about locust

29. Using protein or glycogen can also:
–Liberate water
–Replenish Krebs Cycle intermediates
(Fats burn in the flame of carbohydrates)
–Fuel anaerobic exercise
•
Glycogen
(carbohydrat
e)
Protein Lipid
Water
content (%)
75 70 5
10/23/2019 29All about locust

30. Migrants primarily use fats!
Glycogen
(carbohydrate)
Protein Lipid
Energy Content
DRY matter (kJ/g)
17.5 17.8 39.6
Water content (%) 75 70 5
Energy Content
WET matter (kJ/g)
4.4 5.3 37.6
WHY?
---Fat is ~9 times more energy dense than
other substrates!! Sacktor (1975).
10/23/2019 30All about locust

31. Chemical energy and ATP
• Fat store maximum energy
• 80% of energy
• About 146 ATP from a triglyceride
Molecule Energy
Corbohydrate 4 calories per g
Lipid 9 calories per g
Protein 4 calories per g
Sacktor (1975).10/23/2019 31All about locust

32. Energy reserves during flight of the
desert locust ----
Case study
--Insect flight
muscles are
obligate aerobic
--Derive energy
from oxygen via
substrate
oxidation to Co2
and H2o
--During
flight aerobic
metabolism
take place.
--Energy used
for flight
Co2
(Trehalose)
Fat --
(diacylglycerol
)
Proline (amino
acid)
Are used for
fuel flight
10/23/2019 32All about locust

33. Metabolic scheme showing pathways of
carbohydrate, fat, and proline oxidation in insect
flight muscles.ACETYL-CoA=acetyl-coenzyme A,
ADP=adenosine diphosphate,
ATP=adenosine triphosphate,
CIT=citrate, CYTO=cytosol, DG-
LP=lipoprotein-bound
diacylglycerol,
DHAP=dehydroxyacetone
phosphate, F6P=fructose-6-
phosphate, FDP=fructose
bisphosphate, FA-
CARNITINE=fatty acid-carnitine,
FA-CoA=fatty acid-coenzyme A,
FFA=free fatty acids, G3P=glycerol-
3-phosphate, G6P glucose-6-
phosphate, GAP=glyceraldehyde-3-
phosphate, glut=glutamate,
HCO3−=bicarbonate ion,
H=nicotinamide adenine
dinucleotide, α-KG=ketoglutarate,
MITO=mitochondrion,
OXA=oxaloacetate, PROL=proline,
PYR=pyruvate.10/23/2019 33All about locust

34. Flight muscle metabolism
#Crestine phosphate used as a resorvoir for high energy phosphorl group.
#Muscle fuel proline, glycogen, triglycerol that drawn upon the flight
#Initial flight –small amount require
# Later initial store of ATP in muscle cell are sufficient for flight
#Energy of flight muscle draw several sources
# These substrate are suituated in muscles.
# 10% of chemical energy are used for flight – translated into mechanical energy
#Head can be used for thermoregulation in some insect allow them to fly even when ambient temp is too
low for optimal muscle activity
#Flight require enormous amount of energy bz of high cost of flight
# Conersation of energy in flight muscles operated –aerobically.
10/23/2019 34All about locust

35. w
Utilization of various substrates from the fat
body to fuel flight for muscle contraction.
From Suarez et al. (2005).Copyright © 2005
The energy for flight muscle contraction is
drawn from several sources (Figure 10.38).
Ideally, these substrates would be situated
within the muscles themselves to be close
to where they would be utilized, but the
need to maintain high ratios of muscle
power to weight limits the concentrations
they can attain there, necessitating that the
bulk of the components be stored
elsewhere. Small amounts of substances are
located in the flight muscles themselves to
power the initiation of flight, but the initial
store of ATP in muscle cells is only
sufficient for a few seconds of flight. It is
replenished by the transfer of a phosphate
group to ADP from arginine phosphate,
providing an additional brief period of flight.
This system is similar to vertebrate muscle
where creatine phosphate is instead used as
a reservoir for high-energy phosphoryl
groups. The muscle may also store small
amounts of other fuels including proline,
glycogen, and triacylglycerol that are drawn
upon during flight, but these resources are
similarly limited.
10/23/2019 35All about locust

36. $Flightmuscle draw immiediate source of energy from
hemolymph
$Dissaccharide trehalose present concentration as a
circulating energy source during early phase of flight
$hemolymph diacylglycerol also baths muscle cell
& amino acid proline is utilized in some insect for
flight.
$Hemolyph are mobilized from fat body and
maintain their levels in hemolymph.
10/23/2019 36All about locust

37. Cont...
$Fuel for long flight stored in fat body & tansport to
flight muscles through hemolymph.
$During long flight dipterans, hymenopterans they
convert fat body glycogen into trehalose that is
distributed to muscles through hemolymph.
# Migratory orthopterans utilize triglycerols in fat
body convert to diaclyglycerols.
#Flight muscle completely oxidise corbohydrates to
co2 & H2o in absence of any an aeronic metabolism.
$Glycolysis in insect flight muscle occurs much like
that in other animals.
10/23/2019 37All about locust

38. The process
where glycolysis
take place
Each and every
cell –ellocation
of glycolysis in
cytoplasm
Glycolysis occur
in the presence
and absence of
oxygen.
2 types of
glycolysis
Aerobic
An aerobic
Glycolysis is the enzymatic degradation of glucose production of ATP
molecule.
10/23/2019 38All about locust

39. Sacktor (1975).
10/23/2019 39All about locust

40. Krebscycle
10/23/2019 40All about locust

41. Sathyanarayana (2009).
10/23/2019 41All about locust

42. Glycolysis is the first step in the process of energy production from a glucose molecule which
ends with the production of 2 molecules of pyruvate which then gets converted to citric acid
and enters the citric acid cycle also known as Kreb’s cycle for further production of energy
GLYCOLYSIS KREB’S CYCLE
The reactant is one molecule of glucose The reactant is pyruvate which gets
converted to citric acid which then enters
the cycle
The product is 2 molecule of pyruvic acid Pyruvate is oxidised to carbondioxide and
water
It occurs in cytoplasm of a cell It occurs in the mitochondria of a cell
It can take place both aerobically and
anaerobically
It can take place only in the presence of
oxygen
8 ATP molecules produced 24 ATP molecules produced
2 NADH molecules produced 6 NADH and 2 FADH2 molecules
produced
10/23/2019 42All about locust

43. Gaining Weight
• Generally, longer distance migrants have higher %
body fat.
• Monarchs can carry 60% of body mass as fat, Aphids
only about 30%.
10/23/2019 43All about locust

44. Mixing Fat and Water
• Moving fat through the body is difficult!
• Requires transporters (Fatty Acid Binding
Protein, Fatty Acid Translocase)
FAT
FABP
Mitochondria
Fatty
acid
Sacktor (2000).
10/23/2019 44All about locust

45. Cont..
• Locusts must increase FABP in order to migrate.
• FABP becomes nearly 20% of all protein in the
muscle!!!
Migration
10/23/2019 45All about locust

46. Cont..
FABP is LOW in winter and before
migration
• FABP is High during migration
10/23/2019 46All about locust

47. Other aspects of exercise
physiology
• Locomotory muscle mass
increases
• Mitochondrial density
increases
• Capillary density increases.
10/23/2019 47All about locust

48. More migration physiology
• Endocrine system
– Coordination of behavior and physiology
– Examples:
• Insects: Juvenile Hormone can stimulate flight at
intermediate levels, but suppress migration at high
levels
10/23/2019 48All about locust

49. ...Fact About
locust
10/23/2019 49All about locust

50. FLEDGLINGS TAKE OFF
10/23/2019 50All about locust

51. TRAVELING FOR GENERATIONS
10/23/2019 51All about locust

52. 10/23/2019 52All about locust

53. 10/23/2019 53All about locust

54. 10/23/2019 54All about locust

55. Thank you
10/23/2019 55All about locust