Download insects in the SEM

Insectbodies
Someinsectsliveonthegroundlikeants.
Othershavedifferentlifestages,likethe
caterpillarandthebutterfly.Someadult
insectshavewingsandsocanfly.Onething
insectshaveincommonisthattheyhavesix
legsandahardoutercasingcalledthe
exoskeleton.
LookattheinsectsusingtheSEMsimulator
andnoticesimilaritiesanddifferences.Look
forevidenceofthehardoutercasing.Justlike
whenwewearametalsuitofarmour,andthe
platesneedjointsthatbend,insectsneed
flexiblejointstoo.Seeifyoucanfindsome.
Comparetheadultfleaandhumanheadlouse.
Bothliveonusandfeedonourbloodbutthey
lookverydifferent.Canyouthinkofareason
whybothareflatbutindifferentdirections?
HowinsectsBreathe
Air-breathingisasnecessaryforinsectsasitis
forus.Buttheydon’thavelungslikewedo.
Instead,insectshaveabodyfilledwithtiny
tubesthatcarrytheairaroundtheirbodies.As
theirmusclesmoveithelpstheairmoveabout.
Theairhastogetintothetubesfromtheoutside.Toachievethis,onthesurfaceofaninsectthereare
breathingholescalledspiracles.Seeifyoucanfindanyofthesetinyholeswhenlookingcloselyatthe
insectsintheSEMsimulator.Therearesomevisibleonthebodyofthehumanheadlouse.Seeifyoucan
measuretheirsize.
Tolearnhowtomeasureobjectsshownintheimages,seeMakingMeasurementsUndertheSEM
InformationSheet
InsectSenses
Insectsalsoneedtobeabletosensetheouterworldjustlikewedo.Theyneedtobeabletosee,sense
touch,tosmellandtaste,andsomeevenhearlikewedo.Buttheirsenseorganslookverydifferentfrom
whatweseeonahuman.
Oureyeshaveonelenstoseewith.Incontrast,adultinsectsusuallyhaveeyeswithmanylenses.Seeifany
oftheinsectsseenwiththeSEMsimulatorhavethesekindsofeyes.
Thewayinsectssensetouchisthroughstiffhairsthatstickoutfromthearmouredplates.Whenahair
touchesagainstsomethingitbends.Thatactionpushesonanervecellatthebaseofthehairinsidethe
armourplate,whichinturntellstheinsectbrainwhatisgoingon.Itworksalittlelikepushinganoldfashionedjoy-stickforacomputergame.Seeifyoucanfindanyofthesehairsintheimages.Arethey
presenteverywhere?Aretheremoreofthemincertainareas?Whymightthatbeuseful?
Someofthehairscanalsosmellandtastetheworld.Chemicalstravelthroughthesurfaceofthehairsand
triggernervecellswithin,ratherlikeinournoseoronourtongue.Aninsectnosethough,isonits
antennae.Insectstastewiththehairsontheirmouthparts.Seeifyoucanfindanytastehairsonthe
moth’slongtube-likeproboscis.Theyoftenlookdifferenttoasimplespine-likehairusedfortouch.
Insectcolors
Thearmourthatcoversinsectbodiescanprovideunusualcolors,likethebluethatsparklesinthesunlight
onthewingsofsomebutterflies.Thecolorhelpsmalesandfemalestorecognizeoneanother.Butterflies
makethiscolorwiththeirwingscales.
Thetinyridgesandholesonthescalesbouncebackonlylightofacertaincolor.Seeifyoucanfindsome
oftheseridgesandholesinbutterflyscalesandsilverfishscales.Thebutterflyscalesareblueunder
sunlightwhereasthesilverfishscalesaresilvery-whitelikeapearl.Aretheridgesalwaysthesame
distanceapart?
Ifyouknowaboutthephysicsoflightandthedifferentwavelengthsthatmakecolorsyoucouldcompare
themeasurementsoftheridgesandholeswiththewavelengthsofdifferentcolorsandseehowthey
match.
Insecteggshaveahardoutercasingtoo.Sometimestheyareroundandsometimesflat.Butterflyand
motheggsusuallyhavegroovesandbumpsonthesurface.Beetleeggscanbesmooth,likeatinychicken
egg.Theyallhavebreathingholesinthetopoftheshellthough.
UsingtheSEMsimulatorcanyoufindthebreathing
holesinthetopofthemotheggandforthehumanhead
louseegg?Dotheholeslooksimilarordifferentbetween
thetwotypesofegg?
Canyouseetherimaroundthehumanheadlouseegg
thatwillsplitopentoletthelousehatchout?
Howbigisthelouseegg?Comparethesizewiththe
spacesonanordinarycomb?Whymightthisbea
problemforcontrollingliceinschools?
Internetresources
Therearemanysitestosearchoutthatcantellusmoreaboutinsects.Herearejustafew:
Insectsenseorgans:
http://www.daviddarling.info/encyclopedia/I/insect_senses.html
Howinsectsbreathe:
https://www.youtube.com/watch?v=EALjuKSd2GU
https://www.youtube.com/watch?v=quwhcgkVO3c
Humanheadlice:
https://www.uq.edu.au/news/article/2011/01/avoid-lousy-start-year-observe-national-head-liceawareness-day
http://kidshealth.org/en/parents/head-lice.html