Basic taxonomy
(EE, pp. 51-57)
What is taxonomy?
from the Greek, taxis meaning arrangement or division, and
nomos meaning law.
!
Taxonomy is the science of classification according to a predetermined system, with the resulting catalog used to provide
a conceptual framework for discussion, analysis, or information
retrieval. In theory, the development of a good taxonomy takes
into account the importance of separating elements of a group
(taxon) into subgroups (taxa) that are mutually exclusive,
unambiguous, and taken together, include all possibilities. !
Pre-determined system: use homologies to classify insects into
monophyletic groups
Tree of Life Web Project
http://tolweb.org/tree/phylogeny.html
The Tree of Life Web Project is a
collection of information about
biodiversity compiled
collaboratively by hundreds of
expert and amateur contributors.
Its goal is to contain a page with
pictures, text, and other
information for every species and
for each group of organisms, living
or extinct. Connections between
Tree of Life web pages follow
phylogenetic branching patterns
between groups of organisms, so
visitors can browse the hierarchy of
life and learn about phylogeny and
evolution as well as the
characteristics of individual groups.
Superclass Hexapoda:
The six-legged arthropods
}
6000 spp
800 spp
entognathous hexapods
500 spp
http://tolweb.org/Hexapoda
Historical taxonomic approach...
Pterygota
Wings
Insecta
Apterygota
Wingless
Modern classification (new)...
Dicondylia and
Archaegnatha are
subclasses
Pterygota &
Thysanura are
infraclasses
Pterygota
Dicondylia
Insecta
Thysanura
divergence in jaw structure
Archaeognatha
Taxonomic classifications are hypotheses
2 phylogenies
or
cladograms
The case of the “hemipterans”...
The case of the “hemipterans”...
http://tolweb.org/Hemiptera/8239
the standard tool for separating taxa:
a dichotomous key
Unique characters are rare...
Phylogeny of
Hexapoda
(from p. 52)
•Hexapoda
•Insecta
•Dicondylia
•Pterygota
•Neoptera
•Endopterygota
(Holometabola)
•Orthopteroid orders
•Hemipteroid orders
•Neuropteroid orders
Archaeognatha
Archaeos = ancient; gnatha = jaw
!
Thorax humped; pair of cerci &
longer, central filament
Thysanura
Derived from the Greek Thusanos = tail
!
Abdomen with three roughly equal filaments
Ephemeroptera
Ephemeros = short-lived; ptera = wing
!
Mayflies; two pairs of wings; long cerci and
central filament; aquatic nymphs
Odonata
Damselfly
Dragonfly
Odont= tooth; gnatha = jaw
!
Short antennae; two pairs of richly
veined wings; aquatic nymphs
Plecoptera
Pleiken = braided; ptera= wing
Stoneflies
Blattodea
Blatta = cockroach
Isoptera
Iso = similar; ptera = wing
Mantodea
Mantis = prophet
Grylloblattodea
Grylli = cricket; blatta= cockroach
!
Rock crawlers or ice crawlers
Dermaptera
Dermis = skin; ptera= wing
!
earwigs
Orthoptera
Orthos= straight; ptera=wing
Phasmatodea
Phasma = ghost
!
walking sticks or
stick & leaf insects
Embioptera
Embio = lively; ptera= wing
!
web spinners
Zoraptera
Zor = pure; aptera= wingless
!
Angel insects
Psocoptera
Psokos = gnawed; ptera= wing
!
barklice or booklice
Phthiraptera
phtheiros = louse; aptera = wingless
!
Lice
Hemiptera
Hemi = half; ptera = wing
!
Bugs, aphids, hoppers, etc.
Thysanoptera
Thysanos = fringe; ptera = wing
!
Thrips
4) What does endopterygota signify?
a) no wings
b) partially developed wings
c) externally developed wings
d) internally developed wings
e) external mouthparts
Megaloptera
Mega = large; ptera= wing
!
Alderflies & Dobsonflies
Raphidioptera
rhaphis = a needle; pteron = wing
!
Snakeflies
Neuroptera
Neuron = vein; ptera= wing
!
Lacewings, antlions, and relatives
Coleoptera
Koleo = sheath; ptera= wing
Strepsiptera
Strepsi = twist; ptera = wing
Mecoptera
Meco = long; ptera=wing
Scorpionflies
Siphonaptera
Siphon = tube; aptera = wingless
!
Fleas
Diptera
Di = two; ptera = wing
Trichoptera
Trich = hair; ptera = wing
Caddisflies
Lepidoptera
Lepidos = scale; ptera = wing
!
butterflies & moths
Hymenoptera
Hymen = membrane; ptera = wing
Sawflies, wasps, bees, and ants