Insect Antennae.pdf

Types of antennae in insect

1. INSECT ANTENNAE:
STRUCTURE,
FUNCTIONS AND
MODIFICATIONS
Created and Edited by:-
Vikas Kumar
Student of B.Sc(Agriculture)

2. 2
What is Antenna (Plural= Antennae)?
“Antennaearepaired,freelymobile,segmentedsensory
appendagesarticulatedwiththeheadinfrontoforbetween
theeyes.Antennaearealsoknownasfeelers.”
Thesearewelldevelopedinadultsandpoorlydevelopedin
immaturestages.AntennaeareabsentinorderProturaand
ClassArachnidawhile2pairsofantennaepresentinClass
Crustacea.

3. 3
Structure of Antenna
“Antennaearemultisegmentedandmaybedividedinto3parts:-
1.Scape:-Itisthebasalsegmentofaantenna,bywhichitis
attachedwiththehead.
2.Pedicel:-Itisthesecondsegmentofantennawhichisshorter
thanscape.Thissegmenthavingasensoryapparatusnamed
‘Johnstonorgan’.
3.Flagellum:-Itisthelastsegmentofantennawhichconsists
theremainingdivisionsofantennaanditgreatlyvariesinits
formandstructure.ItisalsoknownasClavola.

4. 4
Structure of Antenna

5. 5
Functions of Antennae
Themainfunctionofantennais
sensory,whichismodified
accordingtohabitandhabitatof
insectasgivenbelow:-
1.Organsofsmell:-Someinsects
havesmellorgansontheir
antennaebywhichthey
recognisetheirfood.E.g.Ant,
HoneyBeeandJiantmoths.

6. 6
2.Organsoftaste:-Someinsects
havetastehairsontheir
antennaebywhichthey
recognisethetasteoftheir
food.E.g.Cockroach.
3.Stridulatorialorgans:-Some
insectbearssoundproducing
organsintheirantennae
belongingorderOrthroptera.
e.g.Cricket.

7. 7
4.ChordotonalOrgans:-Hearingorgans
(Jhonston’sorgan)foundinsecond
segment(pedicel)ofantenna.e.g.
Malemosquito,Greenbottleflyand
Paperwaspetc.
5.SexualDimorphism:-Someinsect
belongingtotheorderDipteraand
Hemiptera,havingdifferenttypeof
Antennainmaleandfemale,which
helpinsexualdimorphism.e.g.Male
andFemaleMosquito.

8. 8
7.OtherFunctions:-
(a).Helpthemandibles
forholdingtheprey.
(b).Usefulforclaspingthe
femaleduringcopulation.
(c).Butterflybearssome
transmittingandreceiving
organsintheirantennae.

9. 9
Modifications of Antennae
Onthebasisofshapeandstructure,
theantennaemaybefollowingtype:-
1.Setaceous:-Thesearebristlelike
antennae,inwhichsegments
graduallydecreaseinsizefrom
basetoapexandtapperingintoa
point,presentingawhiplike
structure.
e.g.CockroachandCricket.

10. 10
2.Filiform(Threadlike):-Itis
threadlikeantennainwhich
segmentsareuniformin
thicknessthroughoutfrom
basetoapexandneverends
withbristle.
e.g.Insectoforder
Orthroptera, Coleoptera
namelyGrasshopperand
GroundBeetle.

11. 11
3.Moniliform(Likestringof
beads):-Suchtypeof
antennaehaveglobularoroval
shapedsegmentswithuniform
thicknessfrombasetoapex,
bywhichitlookslikestringof
beads.Ithaveconstriction
betweenthejoints.
e.g.InsectoforderIsoptera
namelyTermite.

12. 12
4.Pectinate(Comblike):-Thisisa
comblikeinstructureinwhich
eachsegmentoftheantenna
possesslongprojectiononone
side,givingcomblike
appearance.
e.g.InsectoforderLepidoptera
namelyMothofSugarcaneroot
borer.

13. 13
5.Bipectinate(DoubleComb
like):-Inthistypeof
antenna,eachsegmenthas
thelongprojectionson
bothside,givingdouble
comblikeappearance.
e.g.Insectoforder
LepidopteranamelySilk
Moth.

14. 14
6.Serrate(Sawlike):-Inthistype
ofantenna,eachsegmentis
moreorlesstriangularand
projectedononeside,which
givingteethofsawlike
appearance.
e.g.Insectoforder
ColeopteranamelyPulse
beetle.

15. 15
7.Flabellate(Featherlike):-In
thistypeofantenna,inwhich
projectionsoftheflagellum
becomelongandforma
featherlikestructure,whichis
knownasflabella.
e.g.Insectoforder
ColeopteranamelyCedar
Beetle.

16. 16
8.Plumose(burshlikewith
densehairs):-Inthistypeof
antenna,eachsegmenthas
thewhorlsofhairsarisefrom
theirjointsandlooklike
plumose.
e.g.InsectoforderDiptera
namelyMaleMosquito.

17. 17
9.Pilose(burshlikewithsparse
hairs):-Inthistypeofantenna,
eachsegmenthasthewhorls
ofhairsarisefromtheirjoints
likeplumosebutwhorl
containslessnumberofhairs.
e.g.InsectoforderDiptera
namelyFemaleMosquito.

18. 18
10.Whorled:-Basicallytheseare
thesetaceous,filiformor
moniliformtypeofantennae
inwhicheachsegmenthasa
whorlofbristleatevery
joint.
e.g.Insectoforder
HemipteranamelyMaleof
MangoMealyBug.

19. 19
11.Clavate(Clubbed):-Inthistype
ofantenna,segmentsgradually
increaseindiametertowards
thetipandlastsegmentfinally
endingintoaroundcore,look
likeclub.
e.g.InsectoforderLepidoptera
namelyButterfly.

20. 20
12.Capitate(ClubbedwithKnob):-
Inthistypeofantenna,
segmentsgraduallyincreasein
diametertowardsthetipand
suddenlylast3-5segments
enlargetoformaknoblike
structure.
e.g.RedRustFlourBeetle.

21. 21
13.Lamellate(Platelike):-This
isamodificationofcapitate
antennaeinwhichterminal
segmentsextendedonthe
sidetoformleaflikeplate
insteadofformingtheknob.
e.g.RhinocerosBeetle,
DungRollersetc.

22. 22
14.Geniculate(Elbowed):-Inthis
typeofantenna,thescapeis
greatlyelongated,pedicelis
shortandflagellumismade
upofsmallsegmentswhich
makeabentonthescapelook
likeknee.
e.g.Ants,HoneyBeeetc.

23. 23
15.Aristate(Witharista):-Inthis
typeofantenna,scapeis
smallerandbroader,pedicel
islongerthanscape.The
flagellumislongerthanboth
andbearsheavybristle
knownasarista.
e.g.HouseFly.

24. 24
16.Stylate(Withstyle):-In
thistypeofantenna,last
segmentofflagellumis
modifiedintoalong
bristleknownasstyle.
e.g.Snipefly,Robber
fly.

25. 25
17.Fusiform:-Inthistypeof
antenna,scapeissmaller
andthin,whilepedicleis
largerandflagellumis
modifiedintoahooklike
structure.
e.g.SphingidMoth.

26. Any doubtsorsuggestions?
You can find me at:
◉Twitter:-@vikaskashyap__
◉Email:-Vikas Kashyap
Thanks!
26