Insects: Page 2

 

 

Hemiptera-true bugs

  • These are the only animals that can be correctly called bugs!!!

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  • Incomplete metamorphosis (see: green stink bug nymph, and green stink bug adult)
  • Piercing-sucking mouthparts
  • Mothparts originate from front of head (in contrast, the related Homopterans have mouthparts that originate from the lower rear of head - see below)
  • Distinctive forewings
  • membranous at ends, tough/leathery closer to body
  • triangle shaped area of body visible on back when wings folded back
  • Diverse habits
  • mostly terrestrial
  • some species aquatic
  • water bugs, water boatmen, and backswimmers live under water (freshwater)
  • water striders live walking ON the water (prey on insects trapped in water) nice photo of water strider
  • a few species of water striders live on the ocean's surface (these are among the very few marine insects)
  • Diverse food habits, with foods of various species including:
  • sap
  • seeds
  • other insects
  • the blood of vertebrates (e.g. bedbugs)

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    Homoptera- aphids, leafhoppers, cicadas, etc...

  • Incomplete metamorphosis
  • Piercing-sucking mouthparts
  • mouthparts originate from the lower rear of head
  • Typically feeding on plant sap
  • sap high in sugar and water, low in other things insect needs
  • needs to process a lot of sap and excrete excess water and sugar
  • excreted "honeydew" is important food for some other insects
  • some ants tend aphids like herds of dairy cows!

  • Aphids

  • small, very common sap feeders
  • typically parthnogenic when conditions are good (photo of aphid giving birth)
  • males produced and sexual reproduction in Fall
  • often tended/protected by ants

    • Aphids on a plant:

  • Leafhoppers
  • slender sap feeders with hopping legs for fast escapes

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    Also, for more info on leafhoppers, see:Leafhopper Homepage

     

  • Cicadas (see: periodical cicada nymph and adults)
  • Very large, males "sing" loudly to attract mates
  • drum-like membranes under abdomen are vibrated to make the incredibly loud calls
  • Nymphs live underground, feeding on sap in tree roots
  • the common dog day cicadas spend 2 years underground
  • periodical cicadas spend 17 years (!!!) underground
  • entire population emerges all at once
  • enormous densities of adults for a few weeks
  • their collective calls are almost deafening!

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    Diagram of an adult cicda:

     

    Anoplura-sucking lice

  • incomplete metamorphosis
  • feed on blood of a variety of animals
  • superbly adapted for life on their hosts
  • some are specialized for feeding on humans, with different species specialized for different body regions
  • head lice
  • body lice
  • crab lice
  • a huge pain in the neck to rid yourself of once they take up residence on you!!!!
  • eggs (called nits) of head lice are glued to hairs
  • "nit picking" is laborious process, but one of best ways of thoroughly getting rid of lice.
  • human lice are common, and used to be much more common
  • several common phrases originate from widespread dealings with lice
  • "nit picking"
  • "went over it with a fine-teethed comb"

    • human body louse (left), and "claw" for gripping hair (middle), crab louse (right)

     

    Coleoptera - beetles

    Soldier beetle photo (above left) taken by W. Capman

     

  • THE MOST DIVERSE ANIMAL GROUP ON EARTH!
  • Complete metamorphosis
  • larvae are typically grubs of some sort - have various forms:

  • Chewing mouthparts - see mouthparts of a tiger beetle
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  • Diverse food habits/habitats
  • most are plant feeders
  • many predators
  • some parasites (larval stage)
  • some aquatic
  • Forewings are leathery or hardened (e.g. "ladybugs" are beetles)
  • protect hindwings in resting beetle
  • Hindwings membranous and used for flight
  • LOTS AND LOTS OF COOL SPECIES that do strange things, including:
  • Bombadier beetle protects itself with spray of hot caustic liquid
  • Lightningbugs (fireflies) attract mates using light flashes from abdomen tip

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    Lepidoptera-butterflies and moths

  • Complete metamorphosis
  • larvae are caterpillars

  • Mouthparts:
  • larvae - chewing, for plant feeding
  • adults - sucking, tubular proboscis (coiled when at rest) for nectar feeding
  • Very large wings
  • often colorful
  • wings covered in scales (without scales, wings are transparent)
  • See this page (and the links on the page) for info on the significance of wing size: http://web.augsburg.edu/~capman/photoofmonth/monarch.html
  • Butterflies - diurnal (active by day, often only when sun is shining)
  • Moths- most species nocturnal (active by night)
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    Diptera-true flies

     

  • Very diverse group
  • Complete metamorphosis
  • larvae of many species called maggots
  • mosquito larvae aquatic and not maggot-like (the diagram below actually shows mosquito larva upside-down):

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  • Only one pair of functional wings
  • Hindwings reduced to club-like halteres
  • aid in stabilizing flight

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  • Amazingly agile in the air!
  • Diverse mouthparts, including
  • piercing-sucking (e.g. mosquitos, deerflies, horseflies...)
  • mopping
  • Lifestyles....
  • you name it, some fly (or its larval stage) probably does it!
  • a really gross example of the strangeness of some flies...bot flies

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    Siphonaptera- fleas

     

  • Complete metamorphosis
  • Piercing-sucking moutparts for blood feeding
  • Laterrally compressed
  • Hop amazingly well

    • Hymenoptera- ants, bees, wasps, sawflies

  • Complete metamorphosis
  • Chewing mouthparts (modified for sucking or lapping up nectar in some species)
  • Some of the most behaviorally sophisticated insects
  • Some species live solitary lives but many species have special form of sociality called eusociality
  • One reproductive female (the queen) per colony
  • Most of colony consists of non-reproductive females called workers
  • stingers are modified ovipositors - only females can sting
  • Workers care for their mother (the queen) and their younger sisters (and brothers)
  • Males and new queens only produced at certain times
  • new reproductives leave nest all at once
  • males unable to care for themselves, not allowed back to colony or fed by workers after they leave to mate.
  • Fertilized eggs (diploid) develop into females, unfertilized eggs (haploid) develop into males!!!
  • Members of some families are parasitoids
  • parasitic (e.g. on other insects or their eggs) as larvae
  • free-living as adults
  • Ants
  • narrow, constricted "waists" (in contrast, termites are thick-waisted)
  • along with termites, these are the most numerically abundant insects on earth (number of individuals and total biomass, not number of species), greatly exceeding humans in abundance.
  • nest in subterranean burrows
  • feed on lots of things - some are ferocious predators
  • some (slavemaking ants) raid colonies of other species, steal larvae, which grow up to be slaves
  • very complex creatures!
  • Bees
  • defining feature is that bees feed their larvae pollen
  • honey is enyzymatically modified and concentrated (by evaporation) nectar
  • carried to hive in tiny loads in bee's stomachs
  • regurgitated into cells in honeycombs
  • evaporated by fanning wings
  • (not all bees make honey)
  • hairy bodies with "pollen baskets" on certain legs
  • honeybees dance to tell other colony members where to find good nectar and pollen sources

  • not all species are colonial
  • Wasps, hornets, etc.
  • many diverse types
  • many are predators, and gather caterpillars, etc. to feed to larvae
  • many wasp families are parasitoids

    • empty aphid mummies, previously parasitized by a parasitoid (probably a small wasp):

     

    Other orders of insects?......

     

    (Click here for links to additional orders )

    There are a whole bunch more that we have no time to cover!!!