INTERNAL INTERNAL STRUCTURES OF STRUCTURES OF

INSECTINSECT

DIGESTIVE SYSTEMDIGESTIVE SYSTEM

Related with i) digestion; ii) absorption; 3) Related with i) digestion; ii) absorption; 3) water balance; 4) excretionwater balance; 4) excretion

Main division: 1) foregutMain division: 1) foregut

2) midgut2) midgut

3) hindgut3) hindgut

FOREGUT FOREGUT Mouth:Mouth: mandibles break down food mandibles break down food

to small pieces. inside mouth salivary to small pieces. inside mouth salivary glands excrete enzymes to: 1) aid glands excrete enzymes to: 1) aid breakdown of food; 1) add moisturebreakdown of food; 1) add moisture

Phariynx:Phariynx: region that is circled by region that is circled by muscles – force food from mouth to muscles – force food from mouth to esophagusesophagus

EsophagusEsophagus: at tube-like connecting : at tube-like connecting the crop(tembolok)the crop(tembolok)

Crop:Crop: storage area for food. storage area for food. Insect eats beyond repletion, so Insect eats beyond repletion, so need storage before pushed into need storage before pushed into midgutmidgut

Proventriculus: Proventriculus: sometimes sometimes grinding organ (with small teeth; grinding organ (with small teeth; sometimes only as a valve sometimes only as a valve between fore & midgutbetween fore & midgut

FOREGUTFOREGUT

MOUTH MOUTH PHARYNX PHARYNX ESOPHAGUSESOPHAGUS

ENZYMES FROM SALIVARY GLANDS

CROP (TEMBOLOK)

PROVENTRICULUS

FOREGUTFOREGUT

MIDGUTMIDGUT Ventriculus:Ventriculus: Enzymes breakdown food Enzymes breakdown food

chemically, initiate nutrient uptake chemically, initiate nutrient uptake (absorption amino acid, carbo, lipids, vit., (absorption amino acid, carbo, lipids, vit., mineral)mineral)

Single layer epithelial cells, convoluted Single layer epithelial cells, convoluted (berlingkar) & folded: provide absorption (berlingkar) & folded: provide absorption spacespace

The lining is The lining is peritrophic membrane: 1) peritrophic membrane: 1) as as a sieve (penapis) which allows enzymes & a sieve (penapis) which allows enzymes & b/down poducts to move thru it. 2) b/down poducts to move thru it. 2) protect midgutprotect midgut

Gastris caecaGastris caeca (sekum gastrik): involved in (sekum gastrik): involved in harbouring m/organismsharbouring m/organisms

Function of midgut??Function of midgut??

1)1) 2)2)

HINDGUTHINDGUT

Water absorption and waste Water absorption and waste excretionexcretion

Waste products are concentrated Waste products are concentrated and packaged for excretionand packaged for excretion

Consists of Consists of 1) intestine 1) intestine (ileum+colon); 2)rectum; 3) anus(ileum+colon); 2)rectum; 3) anus

From intestine pass to rectal pads: From intestine pass to rectal pads: further salt & water retainedfurther salt & water retained

Malphigian tubulesMalphigian tubules: junction of mid & : junction of mid & hindguthindgut Function: kidneys of insect: absorbs salts, Function: kidneys of insect: absorbs salts,

water and wastes from the surrounding water and wastes from the surrounding hemolymph. The wastes then are released hemolymph. The wastes then are released from the organism in the form of solid from the organism in the form of solid nitrogenous compounds. nitrogenous compounds.

Waste in form of uric acid (dry and Waste in form of uric acid (dry and nontoxic)nontoxic)

Feces Leaf chewing insects very distinctive Feces Leaf chewing insects very distinctive – take the shape of the intestine– take the shape of the intestine

Function: Function: 1) filter hemolymph1) filter hemolymph 2) recover lost metabolites, water & salt2) recover lost metabolites, water & salt 3) excrete waste3) excrete waste

IleumIleumkolon kolon rectum rectum rectum rectum anus anus (waste in form of acid uric- dry & nontoxic(waste in form of acid uric- dry & nontoxic

T. Malphigian border of mid & hindgutT. Malphigian border of mid & hindgut

Insect NutritionInsect Nutrition Diverse Diverse Some insects eat variety plants spp. Some insects eat variety plants spp.

Or maybe restricted to single plantOr maybe restricted to single plant Eg: Eg: Manduca sextaManduca sexta: eats Solanaceae : eats Solanaceae

(tobacco, tomato,potatoes)(tobacco, tomato,potatoes)

What do insects need?What do insects need? 1)FAT (=LIPID)1)FAT (=LIPID)

For hormone production For hormone production 2) CARBOHYDRATE(SUGAR)2) CARBOHYDRATE(SUGAR)

For energyFor energy 3) PROTEINS3) PROTEINS

Need amino acid, for development (eg Need amino acid, for development (eg arganine, leucine, lysine etc)arganine, leucine, lysine etc)

4) Vitamins4) Vitamins Vitamin A for visionVitamin A for vision Vit B1 (thiamine:energy),B2 Vit B1 (thiamine:energy),B2

(riboflavin:energy),B6(pyridoxine:amino acid (riboflavin:energy),B6(pyridoxine:amino acid metabolism)metabolism)

RESPIRATORY RESPIRATORY SYSTEM(TRACHEAL SYS.)SYSTEM(TRACHEAL SYS.)

Gas exchangeGas exchange Insect blood doesn’t contain Insect blood doesn’t contain

haemoglobinhaemoglobin Has massive plumbing with tubes Has massive plumbing with tubes

carry air to cellscarry air to cells GAS (outside)GAS (outside)spiraclesspiracles tracheal tracheal

trunk (pimary trachea)trunk (pimary trachea) 2 2o o & 3& 3oo trachea tracheol

SPIRACLESPIRACLE

Air comes thruAir comes thru Opening on the bodyOpening on the body Open and close (have muscles) to Open and close (have muscles) to

minimize water lossminimize water loss Mechanism: Mechanism:

Co2 high in body Co2 high in body muscles relax muscles relax spricales open Co2 escape + Oxygen inspricales open Co2 escape + Oxygen in

O2 in body approx. outside O2 in body approx. outside muscles muscles recover recover spricales pull shut spricales pull shut

TRACHEAL TRUNKTRACHEAL TRUNK

Spiral of tough filaments (resist collapse)Spiral of tough filaments (resist collapse) Branches to secondary & tertiary tracheaBranches to secondary & tertiary trachea Smaller tubes : tracheolsSmaller tubes : tracheols Tracheols are intimately associatied with Tracheols are intimately associatied with

cellscells Eg: muscles cells: tracheols enter deep into Eg: muscles cells: tracheols enter deep into

the cells: close to mitchondria (where o2 the cells: close to mitchondria (where o2 needed)needed)

OO22 diffuses from tracheols to cells, Co diffuses from tracheols to cells, Co22 from from tissues to tracheolstissues to tracheols

AQUATIC ADAPTATIONAQUATIC ADAPTATION

Some without spiracles, they have Some without spiracles, they have modified gillsmodified gills

The gills with thin layer of cuticles The gills with thin layer of cuticles with lots of tracheoleswith lots of tracheoles

Some have ‘snorkel’ : a tube with Some have ‘snorkel’ : a tube with spiracles- the tube above water for spiracles- the tube above water for air intakeair intake

CIRCULATORY SYSTEMCIRCULATORY SYSTEM

No arteries, veins or capillariesNo arteries, veins or capillaries The organ sits in open cavity filled The organ sits in open cavity filled

with insect blood called with insect blood called ‘HEMOLYMPH’‘HEMOLYMPH’

FUNCTIONSFUNCTIONS

Transport of nutrient and hormonesTransport of nutrient and hormones Storage for substance like acid Storage for substance like acid

aminoamino Water reservoirWater reservoir Hydrostatic pressure for movementHydrostatic pressure for movement Protection from foreign organism Protection from foreign organism

which invadewhich invade

HEMOLYMPHHEMOLYMPH Consists of:Consists of:

1) 90% 1) 90% PLASMAPLASMA:  :   a watery fluid: usually clear, sometimes greenish or a watery fluid: usually clear, sometimes greenish or

yellowishyellowish high concentrations of amino acids, proteins, sugars, and high concentrations of amino acids, proteins, sugars, and

inorganic ions.   inorganic ions.  

1) 10% 1) 10% HEMOCYTES:HEMOCYTES: various cell types various cell types involved in the clotting reaction, phagocytosis, and/or involved in the clotting reaction, phagocytosis, and/or

encapsulation of foreign bodies.   encapsulation of foreign bodies.  

does NOT contain hemoglobin (or red blood cells).   does NOT contain hemoglobin (or red blood cells).   Oxygen is delivered by the tracheal system, not the circulatory Oxygen is delivered by the tracheal system, not the circulatory

system. system.

DORSAL VESSELS (SALUR DARAH)

AORTA•In front of the heart, •lacks valves or muscle.   •continues forward to the head and empties near the brain.   •Hemolymph bathes the organs and muscles of the head as it emerges from the aorta •then back over the alimentary canal,through the body until it reaches the abdomen and re-enters the heart.

HEART•divided segmentally into chambers• that are separated by valves (ostia) to ensure one-way flow of hemolymph.   •A pair of alary muscles are attached laterally to the walls of each chamber.   •Peristalsis: these muscles force the hemolymph forward from chamber to chamber

To facilitate circulation of hemolymph, the body cavity is divided into three

compartments:

DORSAL DIAPHRAGM

VENTRAL DIAPHRAGM

PERICARDIAL SINUS

PERIVISCERAL SINUS

PERINEURAL SINUS

REMEMBER!!!!REMEMBER!!!!

DOES NOT CARRY DOES NOT CARRY OXYGEN!!!OXYGEN!!!

So blood flow is not critical So blood flow is not critical like us humanlike us human

HEMOLYMPH FROM BODYENTER OSTIA( HEART MUSCLE RELAXPERISTALSIS

MOVE FORWARD CHAMBERSAORTA(LACK MUSCLES & VALVE)

BATHES HEADAND ALL ORGANS & BACK TO ABDOMEN

SENSORY SYSTEMSENSORY SYSTEM

Exoskeleton need sensory organExoskeleton need sensory organ To evaluate changes in the To evaluate changes in the

environmentenvironment First info receive by SENSILLA: First info receive by SENSILLA:

specialized cuticullar structure specialized cuticullar structure equipped with nerve cells and equipped with nerve cells and neuronneuron

Usually hair-like Usually hair-like

PHOTORECEPTORPHOTORECEPTOR

Light/visionLight/vision Vision can be restricted in insectsVision can be restricted in insects Some to differentiate light from darkSome to differentiate light from dark Some can distingusih shape & imagesSome can distingusih shape & images 3 types of photoreceptor:3 types of photoreceptor:

1) ocelli1) ocelli 2)stemmata2)stemmata 3) compound eye3) compound eye

OCELLIOCELLI Many adults and nymph of Many adults and nymph of

hemimetaboloushemimetabolous Related to flight, most flightless Related to flight, most flightless

insects don’t haveinsects don’t have Sensitive to light intensitySensitive to light intensity Cannot perceive images or shapeCannot perceive images or shape

STEMMATASTEMMATA

Only on larvae of holometabolousOnly on larvae of holometabolous Larvae of holometabolous almost Larvae of holometabolous almost

never have compound eyesnever have compound eyes capable only of detecting light. capable only of detecting light. cannot focus or allow reception of cannot focus or allow reception of

images. images.

COMPOUND EYESCOMPOUND EYES

Consists of numerous hexagon Consists of numerous hexagon shaped facets/lense called shaped facets/lense called ommatidiumommatidium

2 major components: 1) lenses; 2) 2 major components: 1) lenses; 2) light receiving syst.light receiving syst.

MECHANISMMECHANISM

Lens guide light to a group of pencil-Lens guide light to a group of pencil-shaped like cells tie up together shaped like cells tie up together called rhabdomcalled rhabdom

These photoreceptor absorp the These photoreceptor absorp the light then convert to eletrical signal light then convert to eletrical signal which is conveyed in brainwhich is conveyed in brain

RHODOPSIN: chemical pigment to RHODOPSIN: chemical pigment to absorb light, with the help of absorb light, with the help of Vitamin AVitamin A

Insect eyes cannot focus until sharp Insect eyes cannot focus until sharp imageimage

The best insect eye resolves less The best insect eye resolves less detail than human eyedetail than human eye

But sensitive in movementBut sensitive in movement So what they perceive ? Shape & formSo what they perceive ? Shape & form Broken shapes are differentiated solidBroken shapes are differentiated solid

Some can see coloursSome can see colours Pigments in ommatidia sensitive to Pigments in ommatidia sensitive to

different array of coloursdifferent array of colours Insect sees from 700 nm (red) range Insect sees from 700 nm (red) range

down to 3o0 (violet)down to 3o0 (violet) Bees see flower blueBees see flower blue

CHEMORECEPTORCHEMORECEPTOR

Smell/taste (olfaction)Smell/taste (olfaction) Well developed compared to Well developed compared to

photoreceptorphotoreceptor A) Close range, A) Close range,

chemical signals in solution form (taste)chemical signals in solution form (taste) Found in legsFound in legs Eg: honeybee: taste sweet, sour, salty and Eg: honeybee: taste sweet, sour, salty and

bitterbitter Eg: red admiral butterfly 200x sensitive to Eg: red admiral butterfly 200x sensitive to

sugar than hman tonguesugar than hman tongue

B) distant range (jarak jauh)B) distant range (jarak jauh) Airborne chemical signal = smellAirborne chemical signal = smell Found on antennaeFound on antennae detect odours great distance, milesdetect odours great distance, miles Useful for finding matesUseful for finding mates PHEROMONES: chemical signalsPHEROMONES: chemical signals Smells much more sensitive than Smells much more sensitive than

humanhuman

CHEMORECEPTORCHEMORECEPTOR

MECHANORECEPTORMECHANORECEPTOR

Touch/pressure/vibration or soundTouch/pressure/vibration or sound Sense of pressure/touch usually on Sense of pressure/touch usually on

legs: often contact to groundlegs: often contact to ground Many insects are deaf: sound not Many insects are deaf: sound not

really importantreally important Tympanum: on legs for cricket, on Tympanum: on legs for cricket, on

abdomen for cicadasabdomen for cicadas Hair sensilla in antenna: eg Johnston’s Hair sensilla in antenna: eg Johnston’s

organorgan

THERMORECEPTORTHERMORECEPTOR

Changes in temperatureChanges in temperature Bed bug use thermoreceptor to Bed bug use thermoreceptor to

locate warm blooded verteb.locate warm blooded verteb.

HYGRORECEPTORHYGRORECEPTOR

changes of humiditychanges of humidity Blood feeding parasitesBlood feeding parasites Warm, moist breath good indicator of Warm, moist breath good indicator of

hosthost

NERVOUS SYSTEMNERVOUS SYSTEM INSECT SIMPLE CREATURE????INSECT SIMPLE CREATURE???? What happen when you attack the fly?????What happen when you attack the fly????? 3 components3 components

1)brain1)brain centralcentral 2)ventral nerve cord nervous system 2)ventral nerve cord nervous system

(CNS)(CNS) 3)peripheral nervous system (extend outside 3)peripheral nervous system (extend outside

the central nervos system to serve the limbs the central nervos system to serve the limbs and organs and organs

Each of the components consists millions Each of the components consists millions of neuronsof neurons

VENTRAL NERVE CORD

WHAT IS NEURON?WHAT IS NEURON? Nerve cellNerve cell For information transferFor information transfer Composed of Composed of

1) dendrite (enter the cell body)1) dendrite (enter the cell body) 2) cell body (nucleus found)2) cell body (nucleus found) 3) axon( leaving the body)3) axon( leaving the body)

Repeating unit of neuron form a nervous Repeating unit of neuron form a nervous systemsystem

Individual nerve cells connect with one Individual nerve cells connect with one another through special junctions, called another through special junctions, called synapsessynapses. .

3 categories, depending on their function 3 categories, depending on their function within the nervous system: within the nervous system: 1) Afferent1) Afferent (sensory) neurons (sensory) neurons bipolar or multipolar cellsbipolar or multipolar cells dendrites associated with sense organs or dendrites associated with sense organs or

receptors.   receptors.   carry information carry information towardtoward the central the central

nervous system. nervous system.

D

A

2) Efferent2) Efferent (motor) (motor) neuronsneurons

unipolar cellsunipolar cells conduct signals conduct signals away away

fromfrom the central nervous the central nervous system system

stimulate responses in stimulate responses in muscles and glands. muscles and glands.

D

A

3) Interneurons3) Interneurons unipolar cells (often with several unipolar cells (often with several

collaterals and/or branching collaterals and/or branching axons) that conduct signals axons) that conduct signals withinwithin the central nervous system. the central nervous system.

BRAINBRAIN

Nerve cord to the head is the BRAINNerve cord to the head is the BRAIN 3 pairs of ganglia region:3 pairs of ganglia region:

1)protocerebrum: associated with vision; 1)protocerebrum: associated with vision; they innervate the compound eyes and they innervate the compound eyes and ocelli. ocelli.

2)deotocerebrum: pair lobes with 2)deotocerebrum: pair lobes with sensory pathway to antennaesensory pathway to antennae

3)tritocerebrum: lobes with connective to 3)tritocerebrum: lobes with connective to 11stst ganglion of ventral nerve cord ganglion of ventral nerve cord

VENTRAL NERVE CORDVENTRAL NERVE CORD

1) subesophageal ganglion1) subesophageal ganglion innervates mandibles, maxillae, and innervates mandibles, maxillae, and

labium, hypopharynx, salivary glands, and labium, hypopharynx, salivary glands, and neck muscles.neck muscles.

2) thoracic ganglia 2) thoracic ganglia ) control locomotion by innervating the ) control locomotion by innervating the

legs and wings. legs and wings. 3) abdominal ganglia 3) abdominal ganglia

control movements of abdominal muscles. control movements of abdominal muscles.

PERIPHERAL NERVOUS PERIPHERAL NERVOUS SYSTEMSYSTEM

1) neuron of sensory organs (sensory 1) neuron of sensory organs (sensory neuron)neuron)

2) neuron attached to muscles 2) neuron attached to muscles (motor neuron)(motor neuron)

Function of insect nervous syst Function of insect nervous syst critical in insect controlcritical in insect control

REPRODUCTIVE REPRODUCTIVE SYSTEMSYSTEM

Reproduce: 1) SEXUALLY 2) Reproduce: 1) SEXUALLY 2) ASEXUALLYASEXUALLY

Mosy sexuallyMosy sexually 2 sex cells2 sex cells

1) sperm1) sperm 2) ovum2) ovum

MALE REPRODUCTIVE MALE REPRODUCTIVE SYSTEMSYSTEM

Sperm produce by Sperm produce by testes (A)testes (A) From testes sperm stored in From testes sperm stored in

seminal seminal vesicle (B)vesicle (B)

During copulation discharge During copulation discharge thru thru aedeagus (C) aedeagus (C) (penis) along with (penis) along with secretion from secretion from accessory glands (D)accessory glands (D)

A

B D

C

FEMALE REPRODUCTIVE FEMALE REPRODUCTIVE SYSTEMSYSTEM

Ovum produce by OVARY (A)Ovum produce by OVARY (A) Inside ovaries: OVARIOLES (B) Inside ovaries: OVARIOLES (B)

egg egg producing tubulesproducing tubules

SPERMATHECA (C): storing sperm SPERMATHECA (C): storing sperm -sp. That mate once stored -sp. That mate once stored sperm for months/yearssperm for months/years

ACCESSORY GLANDS (D): provide ACCESSORY GLANDS (D): provide materials for egg to attach to substrate materials for egg to attach to substrate

A

B

C

D