(ee, pp. 174-187) alderflies, dobsonflies, snakeflies, lacewings and antlions
TRANSCRIPT
We are entering a new Subdivision -
the Endopterygota!
• this group contains the most ‘advanced’ and most successful insect orders
• young stages are called larvae - look different from the adults they become
• their wings develop internally (endopterygote)
• metamorphosis is complete (holometabolous)
• transformation from larva to adult takes place during the pupal stage
Megaloptera•Common name: Alderflies and dobsonflies (300 known world species (0.03%))
•Derivation: Gk. megalo - large; pteron - a wing
•Size: Body length 10-150 mm; wingspan 18-170 mm
•Metamorphosis: Complete (egg, larva, pupa, adult)
•Distribution: Widespread, but mainly temperate regions
•Number of families: 2
• two pairs of wings with ....
•hind wings are ....
•hind wings usually....
Megaloptera(not good flyers -
flutter weakly and alight readily)
What about mating?(mating takes place on
marginal vegetation or on the ground)• females produce a
large number of eggs that stick to reeds or other plants hanging over the water
• some male dobson flies (e.g. Protohermes) attach a jelly-like, external spermatophore to the genitalia of the female
Protohermes
• they have simple or branched, abdominal gills (similar in appearance to water beetle families
•when young larvae hatch, the drop or crawl into the water using their well-developed legs
What about the larvae?(all megalopteran larvae are
aquatic and predacious)
•Common name: Snakeflies (200 known world species (0.02%))
•Derivation: Gk. rhaphe - a needle; pteron - a wing
•Size: Body length 6-28 mm
•Metamorphosis: Complete (egg, larva, pupa, adult)
•Distribution: Northern hemisphere
•Number of families: 2
Raphidioptera
Raphidioptera(how do they differ from Megaloptera?)
• larvae are completely terrestrial
• the adult stage feeds
What else do we know?
(snakeflies are not particularly well studied)• they are found in
wooded areas especially among rank vegetation
• adults and larvae like to feed on aphids and other soft-bodied insects
• several hundred eggs are laid, in groups of up to 100, in slits and cracks in tree bark or rotting timber
•Common name: Lacewings, antlions, and their relatives (5000 known species (0.5%))
•Derivation: Gk. neuron - sinew, nerve; pteron - a wing
•Size: Body length 2-90 mm; wingspan 5-150 mm
•Metamorphosis: Complete (egg, larva, pupa, adult)
•Distribution: Worldwide
•Number of families: 18
Neuroptera
spoonwing (nemopterid)
Neuroptera(noted for elaborate venation pattern on the wings)
asc
ala
phid
myrm
ele
on
idmyrmeleonid
Neuroptera(occur worldwide, but many families have restricted
regions)• majority are predacious (as larvae and adults)
• mainly active in the evening or after dark
• some species look like other groups
mantispid mantispid
ascalaphid
Larval morphology(varied and very much linked with lifestyle)
• free-living hunters are slender with longish legs, and often have an adhesive disc-like structure on the last two abdominal segments (for clinging to foliage)
• pit-building or ambushing species tend to be fat and squat with short legs, very large jaws and extended necks
More about the larvae
(interesting gut morphology and development)• eggs laid on a stalk
• the hindgut is not united with the midgut, only fluids are expelled and any solid material is passed as meconium when the adult first emerges (the guts join up in the adult)
• generally mature after 3 instars - pupate inside a spherical, silk coccon