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  • A whip-like straw.

  • Powerful, crushing blades.

  • A pointed, piercing tube.

  • There are nearly a million known insect species in the world,

  • but most have one of just five common types of mouthparts.

  • And that's extremely useful to scientists

  • because when they encounter an unfamiliar insect in the wild,

  • they can learn a lot about it just by examining how it eats.

  • Scientific classification, or taxonomy,

  • is used to organize all living things into seven levels:

  • kingdom,

  • phylum,

  • class,

  • order,

  • family,

  • genus,

  • and species.

  • The features of an insect's mouthparts can help identify which order it belongs to,

  • while also providing clues about how it evolved and what it feeds on.

  • The chewing mouthpart is the most common.

  • It's also the most primitive

  • all other mouthparts are thought to have started out looking like this one

  • before evolving into something different.

  • It features a pair of jaws called mandibles

  • with toothed inner edges that cut up and crush solid foods,

  • like leaves or other insects.

  • You can find this mouthpart on ants from the Hymenoptera order,

  • grasshoppers and crickets of the Orthoptera order,

  • dragonflies of the Odonata order,

  • and beetles of the Coleoptera order.

  • The piercing-sucking mouthpart consists of a long, tube-like structure called a beak.

  • This beak can pierce plant or animal tissue

  • to suck up liquids like sap or blood.

  • It can also secrete saliva with digestive enzymes

  • that liquefy food for easier sucking.

  • Insects in the Hemiptera order have piercing-sucking mouthparts

  • and include bed bugs,

  • cicadas,

  • aphids,

  • and leafhoppers.

  • The siphoning mouthpart,

  • a friendlier version of the piercing and sucking beak,

  • also consists of a long, tube-like structure called a proboscis

  • that works like a straw to suck up nectar from flowers.

  • Insects of the Lepidoptera order

  • butterflies and moths

  • keep their proboscises rolled up tightly beneath their heads

  • when they're not feeding

  • and unfurl them when they come across some sweet nectar.

  • With the sponging mouthpart, there's yet another tube,

  • this time ending in two spongy lobes

  • that contain many finer tubes called pseudotracheae.

  • The pseudotracheae secrete enzyme-filled saliva

  • and soak up fluids and dissolved foods by capillary action.

  • House flies,

  • fruit flies,

  • and the other non-biting members of the Diptera order

  • are the only insects that use this technique.

  • But, there's a catch.

  • Biting flies within Diptera,

  • like mosquitoes,

  • horse flies,

  • and deer flies,

  • have a piercing-sucking mouthpart instead of the sponging mouthpart.

  • And finally, the chewing-lapping mouthpart is a combination of mandibles

  • and a proboscis with a tongue-like structure at its tip

  • for lapping up nectar.

  • On this type of mouthpart,

  • the mandibles themselves are not actually used for eating.

  • For bees and wasps, members of the Hymenoptera order,

  • they serve instead as tools for pollen-collecting and wax-molding.

  • Of course, in nature, there are always exceptions to the rules.

  • The juvenile stages of some insects, for example,

  • have completely different kinds of mouths than their adult versions,

  • like caterpillars, which use chewing mouthparts to devour leaves

  • before metamorphosing into butterflies and moths

  • with siphoning mouthparts.

  • Still, mouthpart identification can, for the most part,

  • help scientistsand youcategorize insects.

  • So why not break out a magnifying lens

  • and learn a little more about who's nibbling your vegetable garden,

  • biting your arm,

  • or just flying by your ear.

A whip-like straw.

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B2 US TED-Ed sucking piercing tube nectar beak

A simple way to tell insects apart - Anika Hazra

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    April Lu posted on 2018/12/05
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