Step A. How many walking legs are present?
a. Zero . . . . . . . . . . . . . . . Go to Step NN
b. 4-6 (2-3 pairs). . . . . . . . . . Go to Step K
c. 8 (4 pairs). . . . . . . . . . . . Go to Step G
d. 10-16 (5-8 pairs). . . . . . . . . Go to Step E
e. 18 (9 pairs) . . . . . . . . . . . Go to Step D
f. 20-24 (10-12 pairs). . . . . . . . Go to Step C
g. 26 or more (more than 13 pairs . . Go to Step B
Step B. How many legs are attached to each
body segment?
a. 2 (1
pair) . . . . . . Class Chilopoda (Centipedes)
b. 4 (2
pairs). . . . . . Class Diplopoda (Millipedes)
Step C. Are eyespots visible on each side of
the head?
a. Yes
. . . . . . Class Chilopoda (immature centipedes)
b. No . . .
. . . . . . . . . . . . Class Symphyla
Step D. Are the antennae branched?
a. Yes. . .
. . . . . . . . . . . . Class Pauropoda
b. No . . .
. . . . Class Chilopoda (immature centipedes)
Step E. Are the legs at the front of the body
notably DIFFERENT in
shape and structure from legs at the back
of the body?
a. Yes. . .
. . . . . . . . . . . . . Go to Step P
b. No . . .
. . . . . . . . . . . . . Go to Step F
Step F. Are gill openings present ventrally on
the last five body
segments?
a. Yes. . .
. Crustacea, Order Isopoda (pillbugs and sowbugs)
b. No . . .
. . . . Class Chilopoda (immature centipedes)
Step G. Are the last pair of legs different in
structure from
the others?
a. Yes. . .
. . . . . . . . . . . . . Go to Step P
b. No . . .
. . . . . . . . . . . . . Go to Step H
Step H. Is the body divided into two parts,
with a distinct
constriction behind the last pair of
legs?
a. Yes. . .
. . . . . . . . . . Order Araneae (spiders)
b. No . . .
. . . . . . . . . . . . . Go to Step I
Step I. Are the first pair of appendages
(pedipalps) enlarged as
pincers?
a. Yes. . .
. . . Order Pseudoscorpiones (Pseudoscorpions)
b. No . . .
. . . . . . . . . . . . . Go to Step J
Step J. Are the legs more than twice as long
as the body?
a. Yes. . .
. . . . . . . . Order Opiliones (Harvestmen)
b. No . . .
. . . . . . . . Order Acarina (mites and ticks)
Step K. Look for evidence of wings on the
thorax.
a. One pair
of wings present. . . . . Go to Step FF
b. Two
pairs of wings present . . . . Go to Step HH
c. Hardened
wing covers present . . . Go to Step EE
d. Short
wing pads present. . . . . . Go to Step R
e. No
visible evidence of wings . . . Go to Step L
Step L. Are visual organs present on the head?
a. Compound
eyes present. . . . . . . Go to Step R
b. Only
simple eyes (ocelli). . . . . Go to Step P
c. No
compound eyes or ocelli . . . . Go to Step M
Step M. How many segments are present in the
antenna?
a. Antennae
apparently absent . . . . Go to Step N
b. 4-8
segments . . . . . . . Order Collembola (springtails)
c. More
than 8 segments . . . . . . . Go to Step O
Step N. Is the head distinct and the body
elongate?
a. Yes. . .
. . . . . . . . . . Order Protura (proturans)
b. No . . .
. . . . . Order Acarina (larval ticks and mites)
Step O. Is there a pair of filaments or
pincers on the end of
the abdomen?
a. Yes. . .
. . . . . . . . . . Order Diplura (diplurans)
b. No . . .
. . . . . . . . . . Order Isoptera (termites)
Step P. How many abdominal prolegs are
present?
a. Zero . .
. . . . . . . . . . . . . Go to Step R
b. 2-10
(1-5 pairs) . . . Order Lepidoptera (moth larvae)
c. More
than 10 (more than 5 pairs) . Go to Step Q
Step Q. Abdominal prolegs are best described
as:
a. Rounded
and fleshy . . . . Order Hymenoptera (sawflies)
b. Slender
and pointed. . . . Order Mecoptera (scorpionflies)
Step R. How many segments are present in the
antennae?
a. Less
than 8. . . . . . . . . . . . . . Go to Step S
b. 8 or
more. . . . . . . . . . . . . . . Go to Step X
Step S. The mouthparts are best described as:
a. Piercing
sucking (slender proboscis) . Go to Step W
b.
Mandibulate (2-4 palps visible). . . . Go to Step U
c. Hidden
within the head . . . . . . . . Go to Step T
Step T. Which of these structures is present?
a. Forked
springing organ (furcula) . . . Order Collembola
b.
Collophore near hind legs. . . . . . . Order Collembola
c. Abdomen
with six segments. . . . . . . Order Collembola
d. Abdomen
with more than six segments. . Order Thysanoptera
e.
Spindle-shaped body. . . . . . . . . . Order Thysanoptera
Step U. Are there 1 or 2 small nodes
(segments) between thorax
and abdomen?
a. Yes. . .
. . . . . . . . . . . Order Hymenoptera (ants)
b. No . . .
. . . . . . . . . . . . . . . Go to Step V
Step V. Are the mandibles and maxillae as long
as the head and
sickle-shaped; also one pair of stout
hooks near the anus?
a. Yes. . .
. . . . . . . . . . . . . . Order Neuroptera
b. No . . .
. . . . . . . . . . . . . . Order Coleoptera
Step W. Where does the proboscis attach to the
head?
a. Near the
front . . . . Order Hemiptera - Heteroptera
b. Near the
back. . . . . Order Hemiptera - Homoptera
Step X. What structures are present on the end
of the abdomen?
a. 2 or 3
long, slender filaments . . . Order Thysanura
b. One pair
of heavy pincers. . . . . . Order Dermaptera
c. Short
cerci, spines, or bare . . . . Go to Step Y
Step Y. Is the first segment of the thorax
significantly narrower
than the head and abdomen -- forming a
slender "neck"?
a. Yes. . .
. . . . . . . . . . . . . . Go to Step Z
b. No . . .
. . . . . . . . . . . . . . Go to Step AA
Step Z. Do the mouthparts face forward or
downward from the head?
a. Forward.
. . . . . . . . . . . Order Isoptera (termites)
b. Downward
. . . . . . . . . . . Order Psocoptera (barklice)
Step AA. Are halteres (knobs or clubs)
present on the thorax?
a. Yes. . .
. . . . . . . . . . . Order Diptera (flies)
b. No . . .
. . . . . . . . . . . . . . Go to Step BB
Step BB. Are there 1 or 2 small nodes
(segments) between the thorax
and abdomen?
a. Yes. . .
. . . . . . . . . . Order Hymenoptera (ants)
b. No . . .
. . . . . . . . . . . . . . Go to Step CC
Step CC. Are the hind legs adapted for
jumping?
a. Yes. . .
. . . . . . . . . . . . . Order Orthoptera
b. No . . .
. . . . . . . . . . . . . . Go to Step DD
Step DD. How long are the antennae?
a. Nearly
as long as the body . . Order Dictyoptera (roaches)
b. Less
than half body length . . Order Coleoptera
Step EE. Does the abdomen end in a pair of
stout pincers?
a. Yes. . .
. . . . . . . . . . . Order Dermaptera (earwigs)
b. No . . .
. . . . . . . . . . . Order Coleoptera (beetles)
Step FF. Are halteres (knobs or clubs)
present on the thorax?
a. Yes. . .
. . . . . . . . . . . Order Diptera (flies)
b. No . . .
. . . . . . . . . . . . . . Go to Step GG
Step GG. The mouthparts are best described
as:
a.
Biting/chewing (mandibulate) . . . Order Hymenoptera
b.
Piercing/sucking (proboscis) . Order Hemiptera - Homoptera
Step HH. The front wings are best described as: a. Covered with a fine dusting of scales. Order Lepidoptera b. Half membranous aand half leathery . . Order Hemiptera c. Rod-like with a long fring of hairs. . Order Thysanoptera d. Opaque and leathery in appearance. . . Go to Step JJ e. Rigid and brittle. . . . . . . . . . . Go to Step EE f. Entirely membranous. . . . . . . . . . Go to Step LL
Step JJ. The mouthparts are best described
as:
a.
Piercing/sucking (proboscis) . . . . . Order Hemiptera
b.
Biting/chewing (mandibulate) . . . . . Go to Step KK
Step KK. Are the hind legs adapted for
jumping?
a. Yes. . .
. . . . . . . . . . . . . . . Order Orthoptera
b. No . . .
. . . . . . . . . . . . . . . Order Dictyoptera
Step LL. Is the first segment of the thorax
significantly narrower
than the head and abdomen --
forming a slender "neck"?
a. Yes. . .
. . . . . . . . . . . . . . . Go to Step MM
b. No . . .
. . . . . . . . . . . . . . . Order Hymenoptera
Step MM. Do the mouthparts face forward or
downward from the head?
a. Forward.
. . . . . . . . . . . . . . . Order Isoptera
b. Downward
. . . . . . . . . . . . . . . Order Psocoptera
Step NN. Is the body divided into segments?
a. Yes. . .
. . . . . . . . . . . . . . . Go to Step PP
b. No . . .
. . . . . . . . . . Aschelminthes (roundworms)
Step PP. How many segments are visible on the
body?
a. Less
than 10 . . . . . . . . . Crustacea or Rotifera
b. 10 to 15
. . . . . . . . . . . . . . . Go to Step QQ
c. More
than 15 . . . . . . . . . . . . . Annelid worms
Step QQ. The head and mouthparts are best
described as:
a. Head
distinct with chewing mouthparts. . . Go to Step RR
b. No
obvious head, but mouthparts are visible . Coleoptera
c. No
visible head or mouthparts. . . . . . . Go to Step VV
Step RR. Are the last pair of spiracles
larger than any others?
a. Yes. . .
. . . . . . . . . . . . . Order Diptera (flies)
b. No . . .
. . . . . . . . . . . . . . . . Go to Step SS
Step SS. Are the head and mouthparts hard and
dark-colored,
contrasting with the appearance of
the thorax?
a. Yes. . .
. . . . . . . . . . . . . . Order Coleoptera
b. No . . .
. . . . . . . . . . . . . . . . Go to Step TT
Step TT. Is the body covered with a dense
coat of hair?
a. Yes. . .
. . . . . . . . . . . Order Siphonaptera (fleas)
b. No . . .
. . . . . . . . . . . Order Hymenoptera
Step VV. Are the last pair of spiracles
larger and more obvious
than the others?
a. Yes. . .
. . . . . . . . . . . Order Diptera (flies)
b. No . . .
. . . . . . . . . . . Order Hymenoptera