1. THE NEOPTEROUS ORDERS PLECOPTERA
(stoneflies)

2. Relative Abundance of the Major Insect Divisions
From the phylogenetic tree:
Endopterygota = Coleopteroids + Strepsiptera + Lepidopteroids + Dipteroids Hymenoptera
Exopterygota = Hemipteroids + Paleoptera + Orthopteroids
Apterygota = Thysanura + Archaeognatha

3. HEMIMETABOLOUS HOLOMETABOLOUS ? Plecoptera Zoraptera Embiodea
Dermaptera
Grylloblattodea
Mantophasmatodea
Polyneoptera
HEMIMETABOLOUS
Phasmida
Orthoptera
Mantodea
Isoptera
Blattaria
Psocoptera
Neoptera
Phthiraptera
Paraneoptera
Thysanoptera
Hemiptera
Coleoptera
Rhaphidioptera
Neuropterida
Megaloptera
Neuroptera
Hymenoptera
HOLOMETABOLOUS
Mecoptera
Siphonaptera
Diptera ?
Panorpida
Strepsiptera
Trichoptera
Lepidoptera

4. Relationships of the Polyneoptera
Plecoptera
Zoraptera
Plecopterida
Embiodea
Dermaptera
Grylloblattodea
Mantophasmatodea
Phasmida
Orthoptera
Orthopterida
Mantodea
Isoptera
Dictyoptera
Blattaria

5. Main features of Polyneoptera
1. Chewing mouthparts

6. Main features of Polyneoptera
1. Chewing mouthparts
2. Nymph with ocelli

7. Main features of Polyneoptera
1. Chewing mouthparts
2. Nymph with ocelli
3. Numerous Malpighian tubules

8. Main features of Polyneoptera
1. Chewing mouthparts
2. Nymph with ocelli
3. Numerous Malpighian tubules
4. CNS with abdominal and thoracic ganglia

9. Embiodea(=Embioptera)
Aquatic nymphs
Ovipositor lost
Plecoptera
Terrestrial nymphs
Silk glands
Embiodea(=Embioptera)
No silk glands
Zoraptera
Dermaptera
prognathous head
Cerci modified to forceps
Cerci not modified
Grylloblattodea ?
Mantophasmatodea
Saltatorial hind legs
Orthoptera
Hind legs not saltatorial
Phasmatodea

10. Why aren’t stoneflies in the Paleoptera?
Similar wing venation
Similar nymphal forms

11. Why aren’t stoneflies in the Paleoptera?
Wing folding
Gill types
& location

12. Stonefly wings

13. Classification of Plecoptera
Order Suborder Superfamily Comment
Plecoptera Anarctoperlaria -southern Hemisphere
-very primitive
Arctoperlaria Systellognatha -mandibles of adult
atrophied
Euholognatha -mandibles of adult
normal
Anarctoperlaria
Systellognatha
Euholognatha

14. Drumming

15. Drumming

16. General Evolutionary Trends
Originated in cold flowing water
Euholognatha
-feed as adults
-diurnal
-herbivorous
Systellognatha
-warmer slower water
-carnivorous (nymphs)
-nocturnal

17. Ecological Classification of Plecoptera
1. Winter stoneflies
2. Summer stoneflies
-emerge in warmer months
-emerge in warmer months
-nymphs are predaceous
-nymphs are detritivores
-adults are non-feeding
-adults are algae or pollen feeders

18. Hexapod Orders Plecoptera Pleco - folded/pleated, ptera - wing
Number of Species
>2000
Common names
Stoneflies, salmonflies
Typical habitats
fast-moving streams -temperate/boreal climates
Distinguishing characteristics
Adults - hind wings shorter; base of hind wing enlarged and pleated
Nymphs - Body flattened, Tracheal gills behind the head, at base of legs, or around the anus, two ‘tails’
Other features
Most primitive of Neoptera