ENTO 305

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ENTO 305

• Wing regions, coupling, and modifications

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Basic Wing Morphology

• Major veins
• Costa
• Subcosta
• Radius
• Media
• Cubitus
• Anal

Costal margin
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Wing folding and sclerites

• Axillary membrane
• Axillary cord
• Anterior NWP
• Posterior NWP
• Basalare
• Subalare

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Pal(a)eoptera (old wing)
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Palaeoptera Dragonfly wing

• 2 large plates at base
• Anterior axillary plate humeral plate, HP
• Posterior axillary plate, AxP
• Articulate with each other and with pleural wing
  process (ventrally)
• Wings not coupled sometimes out of phase during
  flight
• NOTE fusion of sclerites restricts folding back
  of wings over abdomen

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Palaeoptera Mayfly wing

• Lacks anterior (posterior?) axillary
  plate/sclerite
• Wings never folded over abdomen when at rest

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Neoptera (new wing)
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Axillary sclerite 1

• Triangular in shape
• 2 main articulations
• 1subcosta
• 2scutum ANWP
• Flexion

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Axillary sclerite 2

• Irregular in shape
• Joins
• Mesal edge of Ax1
• RM veins
• Pivots on pleural wing process ventrally

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Axillary sclerite 3

• Lies at posterior end of the axillary membrane
• Joins
• 3 anal veins
• Posterior Ax2
• Helps in wing folding

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Median plates

• Anterior MP
• Posterior MP
• Oblique sulcus between MPs
• Major axis if folding

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Question

• Besides resting during flight, why is wing
  folding important?
• Protection (especially for things that crawl in
  constricted spaces)
• Evasion from predators finding a place for
  concealment

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Wing regions

• Claval furrow/fold
• Median flexion line
• Remigium
• Anal region
• Jugal lobe
• Alula
• Calypteres/calypters

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Claval furrow/fold
NOTE Lab on Monday make sure you fix your
figures with this one the claval fold can ONLY
be seen on the inner margin of the wing. Well
look at it next time!
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CF
Remigium
Anal area
Remigium
MFL
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Jugal lobe
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Diptera

• Alula
• Calypteres
• Upper
• Lower
• Halteres hind wings (very reduced)

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Wing coupling - Hymenoptera

• Hamuli little hooks on anterior margin of hind
  wing
• Hymen married ptera wing

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Wing coupling - Lepidoptera

• Jugal coupling primitive groups
• Hooks on leading edge of hind wing clasp onto
  enlarged jugal area of forewing
• Frenate coupling derived groups
• Long bristle (?) or bristles (?) or spine(s)
  (frenulum) on leading edge of hind wing clasp(s)
  onto group of scales on forewing (retinaculum)
• Amplexiform coupling some groups
• Enlarged humeral area (anterior, basal HW)
  overlaps with anal region of FW (costal margin of
  costal vein)

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Wing coupling - Lepidoptera
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Wing modifications

• Sclerotized forewings
• Tegmina Orthoptera and Dermaptera
• Hemelytra Hemiptera/Heteroptera
• Elytra Coleoptera
• Wing reduction
• Halteres (reduced HW) Diptera (FUNCTION?)
• Acts as gyroscope balance during flight
• Apterous no wings
• Flies, Dermaptera, Thysanura, etc.
• Brachypterous shortened/reduced wings
• Gerrids, Orthoptera, etc.

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Tegmina - Orthoptera
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Hemelytra - Hemiptera
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Elytra - Coleoptera

• Possible functions
• Important adaptational mechanisms
• Seal to protect spiracles (pleural and dorsal)
• Prevents dessication (water loss)

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Coleoptera hind wings

• Hind wings are the functional flight wings

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Elytra - Coleoptera
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Halteres - Diptera
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Small insects aptery/brachyptery
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Take-home question

• Very tiny insects can be macropterous, apterous,
  or brachypterous. Regardless of wing type, do
  you think they are more like aerial plankton that
  are blown around by the wind, or do they have
  directed flight?