Entomology 3rd edition - C.Gillott - Chapter 5 ppsx

5
A
pter
yg
ote Hexapod
s
1
. Intr
oduc
t
ion
Traditionally, the groups included in the term “apterygote hexapods,” namely, the Collem
-
b
ola, Protura, Di
p
lura, and Th
y
sanura (includin
g
Microcor
yp
hia and Z
yg
entoma), wer
e
cons
id
ere
d
or

d
ers o
fp
r
i
m
i
t
i
ve
ly
w
i
n
gl
ess
i
nsects an
dpl
ace
di
nt
h
esu
b
c
l
ass A
p
ter

yg
ota
(
Ameta
b
o
l
a). T
h
e
y
s
h
ow t
h
e
f
o
ll
ow
i
n
g
common
f
eatures:
l
ac
k
o

f
w
i
n
g
s,
l
ac
k
o
f
a
pl
eura
l
su
l
cus on t
h
et
h
orac
i
c segments, presence o
f
pregen
i
ta
l
a

bd
om
i
na
l
appen
d
ages, s
li
g
h
tor
absent metamorphosis, and indirect sperm transfer. As more information on their structure
and habits has become available, it has become a
pp
arent that (1) their status as insect
s
(
exce
p
t
f
or T
hy
sanura)
i
s
d
ou
b

t
f
u
l
an
d
(2) t
h
ere
l
at
i
ons
hip
o
f
t
h
e
g
rou
p
sw
i
t
h
eac
h
ot
h

er
is
m
ore
di
stant t
h
an or
igi
na
lly b
e
li
eve
d
. Severa
l
aut
h
ors
h
ave t
h
ere
f
ore recommen
d
e
d
t

h
at t
he
i
nsectan su
b
c
l
ass Apterygota
b
e reserve
d
so
l
e
l
y
f
or t
h
eT
h
ysanura an
d
t
h
at t
h
eCo
ll

em
b
o
l
a
,
Protura, and Diplura each be given the rank of class, with the Collembola and Protur
a
considered as sister
g
rou
p
s within the Elli
p
ura (see Fi
g
ure 1.11). These three
g
rou
p
s differ
f
un
d
amenta
lly f
rom
i
nsects
i

n severa
lf
eatures;
f
or exam
pl
e, t
h
e
y
are ento
g
nat
h
ous,
h
ave
i
ntr
i
ns
i
c muscu
l
ature
i
nt
h
e antennae, an
dl

ac
k
com
p
oun
d
e
y
es w
hi
c
h
are c
h
aracter
i
st
ic
o
f
most
i
nsects, at
l
east
i
nt
h
ea
d

u
l
t stage. T
h
us, t
h
eE
lli
pura an
d
D
i
p
l
ura are somet
i
mes
considered sister groups within the Entognatha. However, other analyses indicate that the
E
ntognatha is a paraphyletic assemblage (see Chapter 1, Section 3.3.1)
.
T
h
eCo
ll
em
b
o
l
a are

p
ro
b
a
bly f
urt
h
est remove
df
rom t
h
ew
i
n
g
e
di
nsects. T
h
e
yp
os-
sess on
ly
s
i
xa
bd
om
i

na
l
se
g
ments, a
p
ostantenna
l
sensor
y
or
g
an s
i
m
il
ar to t
h
eor
g
an o
f
T
om¨osvary found in myriapods, gonads with lateral (rather than apical) germaria, and eggs
¨
i
n which there is total cleavage. Non-insectan features of the Protura are the absence of
antennae (perhaps a secondary condition associated with their soil-dwelling habit), the
occurrence o
f

anamor
ph
os
i
s, an
d
a
g
en
i
ta
l
a
p
erture t
h
at o
p
ens
b
e
hi
n
d
t
h
e 11t
h
se
g

ment
.
D
ipl
ura are su
p
erfic
i
a
lly
s
i
m
il
ar to T
hy
sanura, w
i
t
h
w
hi
c
h
some aut
h
ors
g
rou
p

t
h
em. How
-
ev
e
r,
i
na
ddi
t
i
on to t
h
e
f
eatures ment
i
one
d
a
b
ove, t
h
ey
diff
er
f
rom typ
i

ca
li
nsects
i
n
h
av
i
ng
u
nusual respiratory and reproductive systems. Even though all Thysanura are considered in
-
sectan, it is now apparent that the group contains two distinct subgroups, the Microcoryphi
a
and the Z
yg
entoma
(
=
Th
y
sanur
a
s
ensu str
i
ct
o
)
, to which some authors accord ordina

l
status. T
h
e
p
r
i
mar
yb
as
i
s
f
or t
hi
s
di
st
i
nct
i
on concerns t
h
e mout
hp
arts. In t
h
eM
i
crocor

yphi
a
(
suc
h
as Mac
h
i
l
i
s
a
n
di
ts a
lli
es, t
h
e
b
r
i
st
l
eta
il
s) t
h
e man
dibl

es
h
aveas
i
ng
l
e art
i
cu
l
at
i
on w
i
t
h
11
3
114
C
H
A
PTER
5
the head and bite with a rolling motion. In the Zygentoma (which includes silverfish an
d
fi
rebrats), on the other hand, there is a dicond
y
lic articulation of the mandible, which thu

s
bi
tes transverse
ly
as
i
n
p
ter
yg
ote
i
nsects. As note
di
nC
h
a
p
ter 1,
diff
erences
i
nt
h
e structur
e
an
d
operat
i

on o
f
t
h
e mout
h
parts are o
ff
un
d
amenta
l
p
h
y
l
ogenet
i
c
i
mportance
.
2
.
C
ollembola
S
ynonyms
:
Oli

gentoma, O
li
goentomat
a
C
ommon name:
s
pr
i
ngta
ils
Sma
ll
to m
i
nute w
i
ng
l
ess
h
exapo
d
s;
h
ea
d
pro- or
h
ypognat

h
ous, antennae segmente
d
, compoun
d
e
y
es absent, mouth
p
arts ento
g
nathous; abdomen 6-se
g
mented, t
yp
icall
y
with three mediall
y
situated pregenital appendages (collophore on segment 1, retinaculum on segment 2, furcula on
se
g
ment 4),
g
ono
p
ore on 5th se
g
ment.
Collembola are abundant on ever

y
continent, includin
g
Antarctica. About 6
5
00 s
p
ecies
h
ave
b
een
d
escr
ib
e
d
,
i
nc
l
u
di
ng more t
h
an 1
6
00
f
rom Austra

li
a, 300
f
rom t
h
eUn
i
te
d
K
i
ng-
dom, and about 840 from North America. Individual species may be quite cosmopolitan,
sometimes as a result of human activit
y
when the
y
ma
y
become
p
ests.
Structur
e
Collembola vary in length from about 0.2 to 10 mm. They are generally dark, bu
t
man
y
s
p

ecies are whitish,
g
reen, or
y
ellowish, and some are stri
p
ed or mottled. The bod
y
is either elon
g
ate (Arthro
p
leona) (Fi
g
ure 5.1B) or more or less
g
lobular (S
y
m
p
h
yp
leon
a
and Neeli
p
leona) (Fi
g
ure 5.1A). The head is
p

rimitivel
yp
ro
g
nathous, but is h
yp
o
g
nathous
F
I
GU
RE 5.1. Co
ll
em
b
o
l
a.
(
A
)
Smint
h
urus purpurescens
(
Sm
i
nt
h

ur
id
ae
)
;an
d(
B
)
E
ntomo
b
rya niva
l
i
s
(
Ento
-
mobr
y
idae). [Re
p
rinted from Elliott A. Ma
y
nard, 1951
,
A Monograph o
f
the Collembola or Springtail Insects o
f

N
ew Yo r
k
Stat
e
, Comstoc
k
Pu
bli
s
hi
ng Co., Inc.]
115
A
PTERY
GO
TE
H
EX
A
PODS
i
n the Symphypleona and Neelipleona, and the mouthparts are enclosed within a pouc
h
formed b
y
the ventrolateral extension of the head ca
p
sule. The mouth
p

arts are t
yp
icall
y
o
f
th
ec
h
ew
i
n
g
t
yp
e, t
h
ou
gh i
n man
y
s
p
ec
i
es t
h
e
y
are ras

pi
n
g
or suctor
i
a
l
.T
h
e 4-se
g
mente
d
antennae var
yg
reat
ly i
n
l
en
g
t
h
an
d
eac
h
se
g
ment ma

yb
esu
bdi
v
id
e
di
nto two (se
g
ments
1 and 2) or numerous (segments 3 and 4) subsegments. Immediately behind the antennae
i
s a structure of varied form, the postantennal organ, which appears to have an olfactor
y
function. Com
p
ound e
y
es never occur, but a varied number of ocelli (u
p
to ei
g
ht) ar
e
f
oun
d
on eac
h
s

id
eo
f
t
h
e
h
ea
d
.T
h
et
h
orac
i
cse
g
ments are
di
st
i
nct
i
n Art
h
ro
pl
eona,
b
ut

n
ot
i
n Symp
h
yp
l
eona an
d
Nee
li
p
l
eona;
i
na
ll
spec
i
es t
h
e prot
h
orax
i
s sma
ll
or vest
i
g

i
a
l
.I
n
t
he Symphypleona and Neelipleona the thorax is fused with the abdomen and individua
l
segments are not easily distinguished except at the posterior end. The legs have no true tarsu
s
but
terminate in one or two claws that arise from the tibia. No more than six abdominal
se
g
ments can
b
e
di
st
i
n
g
u
i
s
h
e
d
at an
y

t
i
me (even
d
ur
i
n
g
em
b
r
y
on
i
c
d
eve
l
o
p
ment). T
h
e
first a
bd
om
i
na
l
se

g
ment
b
ears t
h
eco
ll
o
ph
ore (ventra
l
tu
b
e), w
hi
c
h
ar
i
ses
by f
us
i
on an
d
diff
erent
i
at
i

on o
f
t
h
eem
b
ryon
i
c appen
d
ages. T
h
etu
b
e conta
i
nsapa
i
ro
f
ves
i
c
l
es t
h
at ca
n
b
e extruded by hemolymph pressure. The tube appears to have several functions, though it

w
a
s
o
ri
g
inall
y
named because it was thou
g
ht to be adhesive (Greek
colle
,g
lue). Other likel
y
f
unct
i
ons
i
nc
l
u
d
e
g
aseous exc
h
an
g

ean
d
,es
p
ec
i
a
lly
,sa
l
t-water
b
a
l
ance. Most Co
ll
em
b
o
la
h
ave a s
p
r
i
n
gi
n
g
or

g
an (
f
urcu
l
a) on t
h
e
f
ourt
h
a
bd
om
i
na
l
se
g
ment,
h
e
ld
un
d
er tens
i
o
n
b

eneat
h
t
h
e
b
o
d
y
b
ya
h
oo
klik
e structure, t
h
e ret
i
nacu
l
um,
f
orme
df
rom t
h
e appen
d
ages o
f

t
he third abdominal segment. When released from the retinaculum, the furcula is forced
d
ownward and backward by both muscular action and hemolymph pressure. As it strikes
th
esu
b
strate, t
h
ean
i
ma
li
st
h
rown t
h
rou
gh
t
h
ea
i
r, somet
i
mesas
ig
n
i
ficant

di
stance (e.
g
.,
up
to 30 cm
i
n some sm
i
nt
h
ur
id
s). A
bd
om
i
na
l
a
pp
en
d
a
g
es ma
yb
e
g
reat

ly
re
d
uce
di
n sma
ll
su
b
terranean
f
orms. Cerc
i
are a
b
sent
i
nCo
ll
em
b
o
l
a. Some spec
i
es are ecomorp
hi
c, t
h
e

i
r
form changing from instar to instar as a result of unusual environmental conditions, others
a
re cyclomorphic (having seasonally different forms and habits, usually in summer and
w
inter), and some show e
p
itok
y
in which re
p
roductive instars are mor
p
holo
g
icall
y
different
f
rom non-re
p
ro
d
uct
i
ve (
f
ee
di

n
gi
nstars) w
i
t
h
w
hi
c
h
t
h
e
y
a
l
ternate.
Notewort
h
y
f
eatures o
f
t
h
e
i
nterna
l
structure o

f
Co
ll
em
b
o
l
a are t
h
ea
b
sence o
f
Malpighian tubules and, in most species, tracheal system. However, a pair of spiracles
b
etween the head and thorax, leading to tracheae in the head, sometimes also the body, have
b
een re
p
orted for a few S
y
m
p
h
yp
leona. The nervous s
y
stem is s
p
ecialized and include

s
b
ra
i
n, su
b
eso
ph
a
g
ea
lg
an
gli
on, an
d
t
h
ree ventra
lg
an
gli
a, t
h
e
g
an
gli
ao
f

t
h
ea
bd
om
i
na
l
se
g
ments
h
av
i
n
gf
use
d
w
i
t
h
t
h
e metat
h
orac
i
c
g

an
gli
on
.
L
if
eH
i
story and Hab
i
ts
Sp
r
i
n
g
ta
il
s are a
l
most u
biq
u
i
tous,
b
e
i
n
gf

oun
di
n
high l
at
i
tu
d
es (e.
g
., 8
4
◦
south i
n
Antarct
i
ca) an
d
a
l
t
i
tu
d
es (a
b
ove 7700 m
i
nt

h
eH
i
ma
l
ayas),
d
eserts, an
d
g
l
ac
i
ers,
i
na
ddi
t
i
o
n
t
o more conventional biomes. Within these regions they occupy a wide range of habitats,
t
hough they are most abundant and diverse in moist soil, leaf litter, and rotting wood. Other
s
live in dun
g
, in the flesh
yp

arts of fun
g
i, in the nests of termites, ants, and vertebrates, o
n
g
rasses, an
di
n
fl
owers. Severa
l
s
p
ec
i
es occur
i
n caves, on t
h
e sur
f
ace o
f
stan
di
n
g
wate
r
(i

nc
l
u
di
n
g
, rare
ly
,t
id
a
lp
oo
l
s), an
di
n
b
ot
h
mar
i
ne an
df
res
h
water
i
ntert
id

a
l
zones, t
h
ou
gh
v
ery few are truly aquatic. Occasionally, species form large aggregations on the surfac
e
o
f snow, though the significance of this is not clear. Most Collembola cannot tolerate
d
esiccation, and those that colonize dr
y
habitats show various mor
p
holo
g
ical,
p
h
y
siolo
g
ical
,
1
1
6
C

H
A
PTER
5
and behavioral adaptations, such as scales or hairs, specific desiccation-resistant stages
(includin
g
more or less com
p
letel
y
dried out “anh
y
drobiotic” forms), and activit
y
restricte
d
to
p
er
i
o
d
sw
h
en t
h
ere
l
at

i
ve
h
um
idi
t
yi
s
high
.Co
ll
em
b
o
l
a are sa
p
ro
ph
a
g
ous,
f
un
gi
vorous
(
i
nc
l

u
di
n
g
some s
p
ore
f
ee
d
ers), or
phy
to
ph
a
g
ous (
i
nc
l
u
di
n
g
some
p
o
ll
en
f

ee
d
ers), an
d
som
e
species appear to have an intrinsic gut cellulase. Only rarely are they predaceous. Thoug
h
af
ew
f
f
s
pecies are occasionally of economic importance because of the damage they cause
to
p
lants, overall Collembola ma
y
be considered beneficial. B
y
feedin
g
on fun
g
al h
yp
ha
e
an
dd

eca
yi
n
g
mater
i
a
l
,t
h
e
y
ma
yi
n
fl
uence m
y
corr
hi
za
lg
rowt
h
an
d
contro
lf
un
g

a
ldi
sease
s
(Hop
ki
n, 1997)
.
In adult Collembola reproductive and feeding instars alternate. Most species of
C
ollembola reproduce sexually though a few soil-dwelling species are parthenogenetic.
Sp
erm transfer is usuall
y
indirect, males
p
lacin
g
their stalked s
p
ermato
p
hores on the sub
-
strate, to
b
e
f
oun
dbyf

ema
l
es as a resu
l
to
f
a
gg
re
g
at
i
on (
p
er
h
a
p
s
i
nvo
l
v
i
n
gph
eromones) o
r
a
f

ter an e
l
a
b
orate courts
hip d
ance
i
nw
hi
c
h
t
h
ema
l
e
g
ras
p
st
h
e
f
ema
l
eus
i
n
g

s
pi
nes on
hi
s
antennae,
h
ea
d
,or
l
egs, an
dd
raws
h
er over t
h
e spermatop
h
ore. T
h
epa
l
e, sp
h
er
i
ca
l
eggs ar

e
l
aid singly or in small clusters (sometimes several females oviposit collectively) and may
be covered with freshl
y
eaten soil and fecal material, or cleaned b
y
the adults, to
p
revent
f
un
g
a
li
n
f
ect
i
on. T
h
ere
i
s
li
tt
l
ec
h
an

g
e
i
n externa
lf
orm as t
h
e
y
oun
g
an
i
ma
ld
eve
l
o
p
s, an
d
sexual maturit
y
is reached usuall
y
after 5–10 molts. As man
y
as 50 molts ma
y
occur durin

g
t
h
ea
d
u
l
tp
h
ase.
P
hylo
g
eny and Classificatio
n
Accor
di
ng to Ku
k
a
l
ov´a-Pec
k
(1991), t
h
e ear
l
yCo
ll
em

b
o
l
a were sem
i
aquat
i
c. T
h
e
earliest fossil collembolan
,
Rhy
nie
ll
a praecurso
r
,
from the Lower Devonian of Scotlan
d
resembled modern isotomids. Other fossils are known from the Lower Permian of Sout
h
Af
r
i
ca, t
h
eU
pp
er Cretaceous o

f
Cana
d
a, an
d
Tert
i
ar
y
am
b
er
d
e
p
os
i
ts, t
h
e
l
atter
b
e
i
n
g
ass
ig
na

bl
e to extant
g
enera. Current
ly
,t
h
e two most
p
r
i
m
i
t
i
ve
f
am
ili
es are t
h
ou
gh
tto
b
e
t
h
e Hypogastrur
id

ae an
d
Isotom
id
ae, w
i
t
h
t
h
e Entomo
b
ry
id
ae an
d
Sm
i
nt
h
ur
id
ae among t
he
most advanced. Early classifications [e.g., that of Gisin (1960)] arranged extant species
o
f the order Collembola in two suborders, Arthropleona and Symphypleona, principall
y
o
nt

h
e
b
as
i
so
f
t
h
e str
iki
n
g diff
erence
i
n
b
o
dy f
orm, an
d
five
f
am
ili
es. Nowa
d
a
y
s, u

p
to
1
4
f
am
ili
es are reco
g
n
i
ze
d
,an
d
t
h
ese are a
ll
ocate
d
amon
g
t
h
ree or
d
ers w
i
t

hi
nt
h
ec
l
as
s
C
o
ll
em
b
o
l
a, t
h
e roun
d
-
b
o
di
e
d
Nee
lid
ae
b
e
i

ng separate
df
rom t
h
e Art
h
rop
l
eona
i
nt
h
e
i
r
o
w
n
order Neelipleona. However, lack of information prevents the construction of a phylo
-
genetic tree. Of the extant families, the largest and most common are the Hypogastruridae
,
N
eanuridae, On
y
chiuridae, Entomobr
y
idae, Isotomidae, and Sminthuridae
.
Order Arthropleona

S
uperfamily Poduroidea
T
he HYPOGASTRURIDAE (
5
80 species) are generally 1–3 mm in length, whitish,
p
inkish, or darkl
y
colored Collembola with a
p
redominantl
y
holarctic distribution. The
y
h
aveano
b
v
i
ous
p
rot
h
orax, a
g
ranu
l
ar cut
i

c
l
e, an
d
s
h
ort antennae,
b
ut a
p
ostantenna
l
or
g
a
n
may or may not
b
e present. T
h
ey are
f
oun
di
naw
id
e range o
fh
a
bi

tats t
h
oug
h
most spec
i
es
l
ive among decaying vegetation, in soil, in cracks in the bark of trees, or in fungi. Some
hypogastrurids are known as “snow fleas” through their being found, sometimes in immens
e
117
A
PTERY
GO
TE
H
EX
A
PODS
n
umbers, jumping about on snow, usually shortly after a period of mild weather. One widely
d
istributed form
,
Hypogastrura (Ceratophysella) denticulata
(
likel
y
a com

p
lex of severa
l
s
p
ec
i
es), somet
i
mes
b
ecomes a
p
est
i
n mus
h
room ce
ll
ars.
T
h
ema
j
or
i
t
y
o
f

NEANURIDAE (11
6
0s
p
ec
i
es) are
f
oun
d
un
d
er stones an
db
ar
k
,or
i
n soil and leaf litter where they feed on fungal hyphae that they pierce with their shar
p
m
outhparts. Other species, however, are predaceous, eating rotifers, other Collembola, and
t
heir e
gg
s. ONYCHIURIDAE (600 s
p
ecies) are soil- and litter-dwellin
g
collembolans tha

t
l
ac
k
oce
lli
an
d
a
f
urcu
l
a
.
Superfamily Entomobryoidea
The characteristics of the ISOTOMIDAE (over 1000 species) are highly varied, and
future work may well result in its beingsubdivided into several additionalfamilies. Isotomids
are found worldwide, in a ran
g
e of biomes, includin
g
the
p
olar re
g
ions, arid areas, and
seas
h
ores, t
h

ou
gh
man
y
are convent
i
ona
li
n
h
a
bi
tants o
f
so
il
or
l
ea
fli
tter. Man
y
s
p
ec
i
es,
e
s
p

ec
i
a
lly
t
h
eso
il d
we
ll
ers, are cosmo
p
o
li
tan. T
h
e
f
am
ily
ENTOMOBRYIDAE (F
ig
ure
5
.1B), with 136
5
species, includes many of the larger Collembola that reach
5
mm or more
i

n length. Species have a greatly reduced prothorax and a smooth cuticle; a postantenna
l
or
g
an ma
y
or ma
y
not be
p
resent. The
y
ma
y
be found in soil or leaf litter, under bark, i
n
m
oss, an
d
on ve
g
etat
i
on. Some s
p
ec
i
es are natura
lly
cosmo

p
o
li
tan, an
d
ot
h
ers
h
ave
b
ee
n
t
rans
f
erre
d
aroun
d
t
h
ewor
ld by h
uman act
i
v
i
t
y.

Order Neeli
p
leona
The approximately 2
5
species in this order are included in a single family NEELIDAE
.
These tiny collembolans (0.
5
mm or less long) live in soil and leaf litter. They differ from
S
y
m
p
h
yp
leona in that their rounded bod
y
is formed from ex
p
ansion of thoracic rather tha
n
a
bd
om
i
na
l
se
g

ments.
Order Symphypleon
a
Superfami
l
y Smint
h
uroi
d
ea
M
ost of the 890 species of SMINTHURIDAE (Figure
5
.1A) are 1–3 mm in length and
h
ave a roundish body, hypognathous head, and conspicuous ocelli. A postantennal orga
n
i
s absent. Often there is sexual dimorphism, with the antennae of males having hooks and
s
p
ines. Most sminthurids are e
p
i
g
aeic, livin
g
near the surface of leaf litter, or on
g
rasses o

r
ot
h
er
l
ow-
g
row
i
n
g
ve
g
etat
i
on. A num
b
er o
f
s
p
ec
i
es are econom
i
ca
lly i
m
p
ortant. For exam-

pl
e,
S
mint
h
urus
v
iri
d
i
s
,t
h
e
l
ucerne
fl
ea, a Euro
p
ean s
p
ec
i
es
i
ntro
d
uce
di
nto Austra

li
a,
h
as
b
ecome an important pest on alfalfa (lucerne) andother leguminous crops. Other speciesmay
d
o considerable damage in greenhouses and to many garden vegetables at the seedling stage.
L
i
t
e
r
a
t
u
r
e
Accounts of the biolo
gy
of Collembola are
p
rovided b
y
F
j
ellber
g
(1985), Greenslad
e

(
1991, 1994), Ho
pki
n (1997), an
d
C
h
r
i
st
i
ansen an
d
Be
lli
n
g
er (1998). Ke
y
s
f
or t
h
e
ir
i
dentification are to be found in Christiansen and Bellinger (1998) [North American species]
,
G
isin (1960) [European species] (in German), and Greenslade (1991) [Australian families].

118
C
H
A
PTER
5
Christiansen, K., and Bellin
g
er, P., 1998, The Collembola o
f
North America North o
f
the Rio Grande
,
2nd ed.,
G
r
i
nne
ll
Co
ll
ege, Gr
i
nne
ll
, IA.
F
j
ellber

g
, A., 198
5
, Recent advances and future needs in the stud
y
of Collembola biolo
gy
and s
y
stematics
,
Q
uaest
.
E
n
to
m
ol.
2
1:55
9
–570.
Gi
s
i
n, H., 19
6
0
,

C
o
ll
em
b
o
l
enfauna Europas
,
Museum
d
’
hi
sto
i
re nature
ll
e, Geneva.
G
reens
l
a
d
e
,
P.
,
1994
,
Co

ll
em
b
o
l
a
,i
n: Zoo
l
ogica
l
Cata
l
ogue of Austra
l
i
a
,V
ol. 22 (W. W. K. Houston, ed.), CSIRO,
V
V
Melbourne
.
G
reens
l
a
d
e, P. J., 1991, Co
ll

em
b
o
l
a,
i
n
:
Th
e Insects of Austra
l
i
a
,2n
d
e
d
., Vo
l
. I (CSIRO, e
d
.), Me
lb
ourne Un
i
vers
i
t
y
Press

,
Car
l
ton
,
V
i
ctor
i
a
.
H
opkin, S. P., 1997
,
Biology o
f
the Springtails (Insecta: Collembola)
,
Oxford University Press, Oxford.
K
u
k
a
l
ov´a-Pec
k
, J., 1991, Foss
il hi
story an
d

t
h
eevo
l
ut
i
on o
fh
exapo
d
structures,
i
n
:
T
h
e Insects of Austra
l
ia,2n
d
ed
., Vo
l
. I (CS
l
RO, e
d
.), Me
lb
ourne Un

i
vers
i
t
y
Press, Car
l
ton, V
i
ctor
i
a.
3
.Pr
o
t
u
r
a
S
ynonym: M
y
rientomat
a
C
ommon name:
p
ro
t
uran

s
Minute wingless hexapods; head cone-shaped, compound eyes, ocelli, and antennae ab-
sent, mout
h
parts entognat
h
ous an
d
suctor
i
a
l
;
f
ore
l
eg mo
di
fie
d
as a sense organ; a
bd
ome
n
1
2-se
g
mented in adult with a
pp
enda

g
es on first three se
g
ments;
g
ono
p
ore (two in males) behind
1
1t
h
segment; cerc
i
a
b
sent
.
About 660 s
p
ecies of
p
roturans have been described worldwide. Of these, about 80 are
Euro
p
ean (
i
nc
l
u
di

n
g
20
i
nBr
i
ta
i
n), 30 Austra
li
an, an
d
a
b
out 20 Nort
h
Amer
i
can, t
h
ou
gh
t
h
e
l
atter fi
g
ure ma
yb

em
i
s
l
ea
di
n
g
,re
fl
ect
i
n
g
t
h
e
l
ac
k
o
f
taxonom
i
cwor
kd
one on t
hi
s
g

rou
p.
S
tructur
e
P
roturans (Fi
g
ure 5.2) are elon
g
ate,
g
enerall
yp
ale arthro
p
ods 2 mm or less in len
g
th
.
Th
e
h
ea
di
s cone-s
h
ape
d
an

db
ears anter
i
or
l
yt
h
e sty
lif
orm entognat
h
ous mout
h
parts. P
h
o-
toreceptor organs are absent from the head, as are typical antennae. However, a pair o
f
“
p
seudoculi” occur dorsolaterall
y
that ma
y
be humidit
y
rece
p
tors or chemosensor
y

. The
t
h
orac
i
cse
g
ments are
di
st
i
nct, t
h
ou
gh
t
h
e first
i
s
g
reat
ly
re
d
uce
d
.T
h
es

i
x
id
ent
i
ca
ll
e
g
s
h
ave
an unse
g
mente
d
tarsus. T
h
e
f
ore
l
e
g
s are
g
enera
lly
not use
di

n
l
ocomot
i
on
b
ut are
h
e
ld
a
l
o
ft
FI
GU
RE 5.2
.
Ace
r
ella ba
r
be
r
i
,a
p
roturan. [From H. E. Ewin
g
, 1940, The Protura of

North America
,
A
nn. Entomol. Soc. Am.
33
:
495–551. By permission of the Entomologica
l
S
oc
i
et
y
o
f
Amer
i
ca.]
119
A
PTERY
GO
TE
H
EX
A
PODS
and probably act as sense organs. In adult proturans the abdomen is 12-segmented; in th
e
n

ewl
y
hatched animal there are onl
y
9 abdominal se
g
ments, 3 bein
g
added anamor
p
hicall
y
d
ur
i
n
gp
ostem
b
r
y
on
i
c
d
eve
l
o
p
ment. S

h
ort, unse
g
mente
d
or 2-se
g
mente
d
a
pp
en
d
a
g
es w
i
t
h
ev
e
rs
ibl
eves
i
c
l
es are
f
oun

d
on t
h
e first t
h
ree a
bd
om
i
na
l
se
g
ments. Cerc
i
are a
b
sent
.
I
nternally there are no distinct Malpighian tubules, but six papillae occur at the junction
o
f the midgut and hindgut, and these may serve an excretory function. A tracheal system is
p
resent in Eosentomoidea, ori
g
inatin
g
from
p

aired meso- and metater
g
al s
p
iracles, but no
t
i
not
h
er
g
rou
p
s. T
h
e trac
h
eae
d
o not anastomose. T
h
e nervous s
y
stem
i
s
g
enera
li
ze

d
,w
i
t
h
di
screte gang
li
a
i
nt
h
e first seven a
bd
om
i
na
l
segments
.
Life Histor
y
and Habits
Like springtails, proturans are found in a variety of moist habitats. Although frequently
ov
e
rlooked because of their small size, the
y
are
q

uite numerous in certain situations
p
ar
-
ti
cu
l
ar
ly i
nso
il
an
dli
tter. Few
d
eta
il
so
f
t
h
e
i
r
bi
o
l
o
gy
are ava

il
a
bl
e. T
h
e
y
are t
h
ou
gh
tto
b
e
f
un
gi
vorous. It
i
sre
p
orte
d
t
h
at
f
our
j
uven

il
e sta
g
es are
p
asse
d
t
h
rou
gh b
e
f
ore sexua
l
m
aturity is reached (five in male Acerentomidae which have a preimago instar), but it is
n
ot known whether proturans molt when adult. There are probably several generations per
y
ear with, in cooler climates, the adults s
p
endin
g
the winter in a dormant condition.
Phylo
g
eny and
C
lass

ifi
cat
i
on
Tu
x
e
n
(
19
6
4) reco
g
n
i
ze
d
two su
b
or
d
ers an
d
t
h
ree
f
am
ili
es w

i
t
hi
nt
h
ec
l
ass an
d
or
-
d
er Protura, name
ly
,t
h
e Eosentomo
id
ea (
f
am
ily
EOSENTOMIDAE) an
d
Acerentomo
id
e
a
(f
am

ili
es ACERENTOMIDAE an
d
PROTENTOMIDAE). However,
f
o
ll
ow
i
ng t
h
e
d
e-
scription of
S
inentomon er
y
t
h
ranum
b
y Yin (196
5
), which shows morphological fea
-
t
ures of all three families and ma
y
be the most

p
rimitive livin
gp
roturan, some authors
(
e.
g
., Nose
k
, 1973)
h
ave
pl
ace
d
t
hi
ss
p
ec
i
es
i
n
i
ts own su
b
or
d
er S

i
nentomo
id
ea (
f
am
ily
SINENTOMIDAE). T
h
ou
gh
most wor
k
ers cons
id
er t
h
e Eosentom
id
ae an
d
S
i
nentom
id
ae
as t
h
e most pr
i

m
i
t
i
ve proturans, t
h
e
i
r possess
i
on o
f
a trac
h
ea
l
system an
d
certa
i
n
f
eature
s
of their sperm have led Yin (1984) to propose that they are more specialized than the
Acerentomoidea
.
L
i
t

e
r
a
t
u
r
e
M
ost
li
terature on Protura
i
s taxonom
i
c. Accounts o
f
t
h
e
bi
o
l
o
gy
o
f
t
hi
s
g

rou
p
are
gi
ve
n
by
Ew
i
n
g
(1940), Nose
k
(1973), an
d
Im
id
at´e (1991). Nose
k
(1973)
p
rov
id
es a
k
e
y
to t
h
e

E
uropean spec
i
es an
d
Nose
k
(1978) a
k
ey to t
h
ewor
ld
genera; Ew
i
ng (1940)
d
ea
l
sw
i
t
h
t
h
e
N
orth American forms; and Imidat´e
(
1991

)
with the Australian families
.
E
wing, H. E., 1940, The Protura of North America
,
Ann. Entomol.
S
oc. Am
.
33
:
4
9
5–551
.
Im
id
at´e, G., 1991, Protura,
i
n
:
Th
e Insects of Austra
l
ia
,
2n
d
e

d
., Vo
l
. I (CSIRO, e
d
.), Me
lb
ourne Un
i
vers
i
ty Press,
Car
l
ton
,
V
i
ctor
i
a.
N
osek, J., 1973
,
The Euro
p
ean Protur
a
,
M

u
seum d’histoire naturelle, Geneva
.
N
ose
k
, J., 1978, Key an
ddi
agnos
i
so
f
Protura genera o
f
t
h
ewor
ld
, Annot. Zoo
l
. Bot. Bratis
l
av
a
122
:1–59.
T
uxen
,
S. L.

,
19
6
4
,
Th
e Protura. A Revision of t
h
e Species of t
h
eWor
ld
wit
h
Keys for Determination
,
Hermann
,
Par
i
s.
Yin, W Y., 1965, Studies on Chinese Protura. II. A new family of the suborder Eosentomoidea,
Acta
En
to
m
ol.
S
in.
14

:186–195. (In Chinese with English summary.)
Y
in, W Y., 1984, A new idea on phylogeny of Protura with approach to its origin and position,
YY
S
ci. Sin.
(
B
)
2
7:149–160.
120
C
H
A
PTER
5
4
. Diplur
a
S
ynonyms
:
Dicellura, Entotro
p
hi, Ento
g
nath
a
C

ommon name
:
d
i
p
luran
s
Elongate apterygotes; head with long many-segmented antennae, compound eyes, and ocelli
ab
sent, mout
h
parts entognat
h
ous; t
h
orac
i
c segments
di
st
i
nct,
l
egs w
i
t
h
unsegmente
d
tarsus; a

b
-
d
omen 10-se
g
mented, most
p
re
g
enital se
g
ments with st
y
li, eversible vesicles on some abdomina
l
segments, cerc
i
present as e
i
t
h
er
l
ong mu
l
t
i
annu
l
ate or

f
orceps
lik
e structures, gonopore
b
etween
se
g
ments 8 an
d
9.
More t
h
an 800 s
p
ec
i
es o
f
t
hi
sw
id
e
ly di
str
ib
ute
d
,t

h
ou
gh
ma
i
n
ly
tro
pi
ca
l
or su
b
tro
pi
ca
l
,
o
r
d
er
h
ave
b
een
d
escr
ib
e

d
. Most
h
o
l
arct
i
c
f
orms
b
e
l
on
g
to t
h
e
f
am
ily
Cam
p
o
d
e
id
ae,
i
nc

l
u
d-
i
ng t
h
e11Br
i
t
i
s
h
spec
i
es. Just over
6
0 spec
i
es
h
ave
b
een
d
escr
ib
e
df
rom Nort
h

Amer
i
ca,
and about 30 from Australia.
S
tructur
e
In
g
eneral form Di
p
lura (Fi
g
ure
5
.3) resemble Th
y
sanura but differ in bein
g
ento
g-
nathous and lacking a median process on the last abdominal segment. Most species are
a
f
ew millimeters long, but a few may reach almost 60 mm. The roundish or oval head carrie
s
the multise
g
mented antennae, whose fla
g

ellar se
g
ments (exce
p
t the most distal) are
p
ro-
vid
e
d
w
i
t
h
musc
l
es. T
h
ere
d
uce
dbi
t
i
n
g
mout
hp
arts occu
py

a
p
ouc
h
on t
h
e ventra
l
sur
f
ace.
Th
es
i
x
id
ent
i
ca
ll
e
g
s
h
ave an unse
g
mente
d
tarsus. Two to
f

our
l
atera
l
s
pi
rac
l
es occur on t
he
thorax. Ten abdominal segments are distinguishable. The sterna of segments 2–7 bear styli
,
and eversible vesicles occur on a varied number of segments. The conspicuous cerci vary in
structure and are an im
p
ortant taxonomic feature. In most Di
p
lura (but not Cam
p
odeidae,
whi
c
hh
ave none) t
h
ere are seven
p
a
i
rs o

f
a
bd
om
i
na
l
s
pi
rac
l
es.
F
IGURE 5.3.
Di
p
l
ura. (A) Cam
p
odea
s
p. (Campo
d
e
id
ae); (B) Anajapyx vesiculosus
(
Ana
j
apyg

id
ae); an
d
(
C
)
H
etero
j
apyx
sp
. (Hetero
j
a
pyg
idae). [From A. D. Imms, 19
5
7,
A
Genera
l
Text
b
oo
k
of Entomo
l
ogy
,
9t

h
e
d
.
(revised b
y
O. W. Richards and R. G. Davies), Methuen and Co.
]
121
A
PTERY
GO
TE
H
EX
A
PODS
As in Protura, Malpighian tubules are represented usually by a varied number of papilla
e
at the
j
unction of the mid
g
ut and hind
g
ut. The tracheal s
y
stem is develo
p
ed to a varied extent.

Trac
h
eae
l
ea
di
n
gf
rom one s
pi
rac
l
e never anastomose w
i
t
h
t
h
ose
f
rom ot
h
er s
pi
rac
l
es, an
d
th
e

yl
ac
k
cut
i
cu
l
ar su
pp
ort
i
n
g
r
i
n
g
sc
h
aracter
i
st
i
co
fi
nsectan trac
h
eae. T
h
e nervous s

y
stem
is
n
ot specialized, the ventral nerve cord containing eight (Japygidae) or seven (other Diplura
)
abdominal ganglia. The reproductive system is greatly varied within the Diplura, although i
n
all s
p
ecies the
g
ermaria are a
p
ical. I
n
J
apyx
(
Ja
pyg
idae) there are seven
p
airs of se
g
mentall
y
arran
g
e

d
ovar
i
o
l
es,
i
n
A
na
j
apyx (Ana
j
a
pygid
ae) two, an
din
C
ampode
a
(
Cam
p
o
d
e
id
ae) one
.
One or two pa

i
rs o
f
testes occur
i
nt
h
ema
l
e.
Life Histor
y
and Habits
Because o
f
t
h
e
i
r rat
h
er secret
i
ve
h
a
bi
ts
li
tt

l
e
i
s
k
nown o
f
t
h
e
lif
e
hi
story o
fdi
p
l
urans.
They are found in damp habitats, for example, leaf litter, under stones and logs, and in soil
.
The cam
p
odeids are herbivorous, but other Di
p
lura are carnivorous, catchin
gp
re
y
with
th

e
i
r
f
orce
p
s (mo
di
fie
d
cerc
i
)orw
i
t
h
t
h
e
i
r max
ill
ae. L
ik
ema
l
es
p
r
i

n
g
ta
il
s, ma
l
e
dipl
urans
d
e
p
os
i
t sta
lk
e
d
s
p
ermato
ph
ores
b
ut ma
k
e no attem
p
t to attract
f

ema
l
es to t
h
em. T
h
ee
ggs
a
re
l
a
id i
n groups
i
nac
h
am
b
er
d
ug
b
yt
h
e
f
ema
l
e. In some spec

i
es t
h
e
f
ema
l
e guar
d
st
h
e
e
ggs and young. Development is slow and molting (up to 30 times in Cam
p
o
d
ea
)
continues
t
hrou
g
h life
.
Phylogeny and
C
lass
ifi
cat

i
on
Fossil Di
p
lura are known from the U
pp
er Carboniferous of Illinois (
T
estajapyx thomas
i
)
th
ou
gh
at t
hi
s sta
g
et
h
ea
pp
en
d
a
g
es were st
ill f
u
lly

se
g
mente
d
,e
y
es were
p
resent, an
d
t
h
e
e
ntognat
h
ous con
di
t
i
on was not
f
u
ll
y
d
eve
l
ope
d

;t
h
at
i
s, t
h
e
l
atera
l
marg
i
ns o
f
t
h
e
h
ea
d
were not fused with the labium to form a pouch around the mandibles and maxillae. Extan
t
Diplura were arranged by Paclt (19
5
7) in three families [CAMPODEIDAE, PROJAPY
-
G
ID
A
E

(
=
A
NAJAPYGIDAE
)
, and JAPYGIDAE]. However, more recent classifications
[e.
g
., t
h
at o
f
Con
d
´ean
d
Pa
g
´es (1991)] ten
d
to ra
i
se t
h
esu
bf
am
ili
es w
i

t
hi
nt
h
ese
g
rou
p
sto
t
he rank of famil
y
.Incam
p
odeids (Fi
g
ure
5
.3A), which ma
y
reach 4 mm at maturit
y
, the
cerci are multiannulate and usually as long as the abdomen. In contrast, the projapygids
(
Figure
5
.3B) are minute arthropods with relatively short cerci (less than half the length o
f
t

he abdomen and havin
g
fewer than 10 subdivisions). The cerci of
j
a
pyg
ids (in the sense of
Paclt, 1957) take the form of stron
g
l
y
sclerotized, undivided force
p
s (Fi
g
ure 5.3C)
.
L
i
t
e
r
a
t
u
r
e
G
enera
li

n
f
ormat
i
on on D
ipl
ura
i
s
gi
ven
by
Wa
ll
wor
k
(1970) an
d
Con
d
´ean
d
Pa
g
´es
(
1991). Most Nort
h
Amer
i

can spec
i
es can
b
e
id
ent
i
fie
df
rom Sm
i
t
h
(19
6
0), t
h
eBr
i
t
i
s
h
species from Delany (19
5
4), and the Australian families from Cond´e and Pag´es (1991)
.
Cond´e, B., and Pag´es, J., 1991, Diplura, in:
T

he Insects o
f
Australi
a
,
2nd ed., Vol. I (CSIRO, ed.), Melbourne
U
n
i
vers
i
t
y
Press, Car
l
ton, V
i
ctor
i
a
.
Delan
y
, M. J., 19
5
4, Th
y
sanura and Di
p
lura

,
R. Entomol.
S
oc. Handb. Ident. Br. Insects
1
(
2
)
:1–7.
P
aclt, J.,1957, Diplura,
G
enera Insect.
212
:1
–
123.
S
m
i
t
h
, L. M., 19
6
0, T
h
e
f
am
ily

Pro
j
a
pygid
ae an
d
Ana
j
a
pygid
ae (D
ipl
ura)
i
n Nort
h
Amer
i
ca
,
A
nn. Entomo
l
. Soc
.
A
m
.
5
3

:575
–
583.
W
allwork, J. A., 1970
,
Ecology o
f
Soil Animals
,M
c
Graw-Hill, New York
.
122
C
H
A
PTER
5
5. Microcoryphia
Synonyms
:
A
rc
h
eo
g
nat
h
a, Ectotro

phi
(
i
n
p
art)
,
C
ommon name:
b
r
istletails
E
cto
g
natha (in
p
art)
Small or moderately sized apterygote insects; head with long multiannulate antennae, large
c
ont
ig
uous com
p
oun
d
e
y
es, oce
lli

, ecto
g
nat
h
ous c
h
ew
i
n
g
mout
hp
arts, man
dibl
es w
i
t
h
s
i
n
gl
ear-
ticulation, maxillar
yp
al
p
s 7-se
g
mented; thorax stron

g
l
y
arched with ter
g
a extendin
g
over
p
leura
,
l
egs w
i
t
h
3 (rare
l
y 2) tarsa
l
segments; a
bd
omen 11-segmente
d
,t
h
oug
h
10t
h

segment re
d
uce
d
an
d
ter
g
um o
f
11t
hf
orm
i
n
g
me
di
an cau
d
a
l
fi
l
ament,
p
a
i
re
d

st
yli p
resent on eac
h
a
bd
om
i
na
l
se
g
ment
,
long cerci with multiple subdivisions present.
As note
di
nt
h
e Intro
d
uct
i
on to t
hi
sc
h
a
p
ter, M

i
crocor
yphi
aan
d
Z
yg
entoma (see Sect
i
o
n
6
) were or
igi
na
lly
un
i
te
di
nt
h
eor
d
er T
hy
sanura. However,
f
un
d

amenta
l diff
erences
i
nt
h
e
ir
structure (compare t
h
e
d
efin
i
t
i
ons o
f
t
h
eor
d
ers)
h
ave
l
e
d
to t
h

e
i
r separat
i
on as
di
st
i
nct
o
rders. The Microcoryphia form a small (about 3
5
0 species) but cosmopolitan group, wit
h
about 35 s
p
ecies in North America (mostl
y
Machilidae), 7 in Australia (all Meinertellidae),
an
d
7
i
nBr
i
ta
i
n(a
ll
Mac

hilid
ae)
.
Structur
e
Microcoryphia (Figure
5
.4A) are elongate insects up to 20 mm in length. Their body i
s
strongly convex dorsally (with the large terga extending around the sides to cover the pleura)
,
g
enerall
y
ta
p
ered
p
osteriorl
y
, and covered with scales. The head is h
yp
o
g
nathous, in som
e
s
p
ec
i

es
p
ro
g
nat
h
ous, an
d
carr
i
es
p
rom
i
nent c
h
ew
i
n
g
mout
hp
arts, t
h
e
l
on
g
, 7-se
g

mente
d
max
ill
ar
yp
a
lp
s
b
e
i
n
gp
art
i
cu
l
ar
ly
cons
pi
cuous. Eac
h
man
dibl
e
h
as a s
i

n
gl
e art
i
cu
l
at
i
on w
i
t
h
t
h
e
h
ea
d
.T
h
e antennae are fi
lif
orm an
d
compr
i
se 30 or more su
bdi
v
i

s
i
ons t
h
at
l
ac
ki
ntr
i
ns
ic
musculature. Compound eyes are well developed and contiguous (meet in a middorsa
l
p
osition). Median and paired lateral ocelli are also present. The legs have three tarsal
se
g
ments an
d
,
i
n some s
p
ec
i
es, t
h
ose o
f

t
h
e mesot
h
orax an
d
metat
h
orax
b
ear coxa
l
st
yli
.
Abd
om
i
na
l
st
yli
occur on se
g
ments 2–9, an
d
evers
ibl
eves
i

c
l
es are a
l
most a
l
wa
y
s
f
oun
d
o
na
bd
om
i
na
l
segments 1–7. In
f
ema
l
es an ov
i
pos
i
tor
i
s

f
orme
df
rom t
h
e appen
d
ages o
f
(
Machil-
e
d from
ni
vers
i
t
y
,
9th ed
.
123
A
PTERY
GO
TE
H
EX
A
PODS

abdominal segments 8 and 9. In males the appendages of the ninth abdominal segment fus
e
t
o form a median
p
enis.
I
nterna
lly
M
i
crocor
yphi
aex
hibi
t
f
eatures t
h
at m
igh
t
b
eex
p
ecte
d
o
fp
r

i
m
i
t
i
ve
i
nsects.
T
h
ey
h
ave 12–20 Ma
l
p
i
g
hi
an tu
b
u
l
es, a nervous system t
h
at
i
nc
l
u
d

es pa
i
re
dl
ong
i
tu
di
na
l
connectives, 3 thoracic and 8 abdominal ganglia, 9 pairs of spiracles and tracheae that d
o
n
ot anastomose with those of adjacent segments, and a primitive reproductive system. In
females there are t
yp
icall
y
sevenorei
g
ht
p
anoistic ovarioles on each side of the bod
y
,an
d
i
n some s
p
ec

i
es t
h
ese are arran
g
e
di
n a more or
l
ess se
g
menta
l
manner. Fema
l
es
l
ac
k
a
spermat
h
eca. In ma
l
es eac
h
test
i
s compr
i

ses t
h
ree or
f
our
f
o
lli
c
l
es, an
d
t
h
evas
d
e
f
erens on
e
ach side is double, the two channels being connected by several transverse tubes.
L
if
eH
i
story and Hab
i
ts
Mi
crocor

yphi
a are usua
lly
nocturna
l
,
hidi
n
gbyd
a
yi
n rott
i
n
g
woo
d
, amon
gl
eaves,
i
n
crev
i
ces, un
d
er stones, etc., an
d
are restr
i

cte
d
to suc
hh
a
bi
tats
b
yt
h
e
i
r
i
na
bili
ty to res
i
st
d
esiccation. They are phytophagous or omnivorous, feeding on algae, lichens, leaf litter
,
and sometimes other arthropods. Bristletails can run fairly quickly and sometimes jump (up
t
o
10
cm
).
Deta
il

so
f
t
h
e
lif
e
hi
stor
y
o
f
M
i
crocor
yphi
a are not we
ll k
nown. T
h
ou
gh p
art
h
eno-
g
enes
i
s occurs
i

n some spec
i
es, repro
d
uct
i
on
i
s usua
ll
y sexua
l
,ma
l
es
l
eav
i
ng sta
lk
e
d
sper-
m
atophores on the substrate or placing a sperm droplet on the ovipositor. Females lay eggs
singly or in batches of up to 30 in crevices or holes dug with the ovipositor. The absence of
as
p
ermatheca su
gg

ests that matin
g
must occur fre
q
uentl
y
. Postembr
y
onic develo
p
ment i
s
s
l
ow (
g
enera
lly
ta
ki
n
g
severa
l
mont
h
stoa
y
ear
f

rom
h
atc
hi
n
g
to a
d
u
l
t
h
oo
d
)an
di
nc
l
u
d
es
at
l
east five
j
uven
il
e
i
nstars

i
n
M
ac
h
i
l
i
s.
M
o
l
t
i
n
g
cont
i
nues
i
na
d
u
l
ts.
Phylogeny and
C
lass
ifi
cat

i
on
Fossil machilids are known from as earl
y
as the Lower Devonian of Quebec. Ex
-
t
ant s
p
ec
i
es are
pl
ace
di
nt
h
es
i
n
gl
esu
p
er
f
am
ily
Mac
hil
o

id
ea, conta
i
n
i
n
g
two
f
am
i
-
li
es, t
h
e MACHILIDAE an
d
t
h
e more
p
r
i
m
i
t
i
ve MEINERTELLIDAE. T
h
e

f
ormer
is
pr
i
nc
i
pa
ll
y a Nort
h
ern Hem
i
sp
h
ere group w
hil
et
h
e
l
atter
i
sma
i
n
l
y
f
rom t

h
e Sout
h
ern
Hemisphere.
Literatur
e
S
ee un
d
er Sect
i
on
6
(Zygentoma)
.
6
.Zy
g
entoma
S
ynonyms:
T
h
y
sanura
(
s
ensu str
i

ct
o
)
,
C
ommon name
:
silverfish
,
firebrats
Ectotrop
hi
(
i
n part),
Ecto
g
natha (in
p
art)
S
mall or moderatel
y
sized, dorsoventrall
y
flattened a
p
ter
yg
ote insects; head with lon

g
mul-
ti
annu
l
ate antennae, compoun
d
eyes sma
ll
or a
b
sent, oce
lli
a
b
sent (except Lep
id
otr
i
c
hid
ae),
e
cto
g
nathous chewin
g
mouth
p
arts, mandible with dicond

y
lic articulation, maxillar
yp
al
p
5
-segmented; legs with 2–4 tarsal segments; abdomen 11-segmented but with 10th segment
124
C
H
A
PTER
5
r
educed and ter
g
um of 11th se
g
ment formin
g
median caudal filament,
p
aired st
y
li on abdominal
segments 7–9 (rare
l
y 2–9), cerc
i
genera

ll
y
l
ong w
i
t
h
mu
l
t
i
p
l
esu
bdi
v
i
s
i
ons,
b
ut somet
i
mes qu
i
te
short, stron
g
l
y

diver
g
in
g
from bod
y
.
T
he Z
yg
entoma is a small, worldwide order of about 370 s
p
ecies that are both struc-
tura
lly
an
d
eco
l
o
gi
ca
lly
more
di
verse t
h
an m
i
crocor

yphi
ans. A
b
out 30 s
p
ec
i
es
h
ave
b
een
d
escr
ib
e
df
rom Nort
h
Amer
i
ca, w
i
t
h
a
b
out t
h
e same num

b
er
f
rom Austra
li
a,
i
nc
l
u
di
n
g
some
t
h
at are cosmopo
li
tan an
d
occas
i
ona
ll
y pests, an
d
2
f
rom Br
i

ta
i
n(
b
ot
h
Lep
i
smat
id
ae).
S
tructur
e
Zyg
entoma (Fi
g
ure 5.4B) are broadl
y
similar to Microcor
yp
hia, and onl
y
the more
i
m
p
ortant
diff
erences

i
n structure w
ill b
e note
dh
ere. T
h
e
b
o
dy
o
f
Z
yg
entoma
i
s
d
orsoven-
tra
ll
y
fl
attene
d
an
d
may or may not
h

ave sca
l
es. Compoun
d
eyes are re
d
uce
d
or a
b
sent an
d
o
celli do not occur (except in Lepidotrichidae). The maxillary palps are
5
-segmented, and
the mandibles have a dicond
y
lic articulation with the head, as do those of
p
ter
yg
ote insects.
Th
e
l
e
g
s
i

nc
l
u
d
e 2–4 tarsa
l
se
g
ments. A
bd
om
i
na
l
st
yli
norma
lly
occur on
ly
on se
g
ments
7
–9, t
h
ou
gh i
nN
i

co
l
et
iid
ae t
h
e
y
are
f
oun
d
on se
g
ments 2–9. Evers
ibl
eves
i
c
l
es are a
b
sent
in
many Lep
i
smat
id
ae
b

ut occur on a
bd
om
i
na
l
segments 2–7
i
nN
i
co
l
et
iid
ae an
d
Lep
id
otr
i
c
hi
-
dae. In most species the cerci are long, multiannulate structures that diverge sharply fro
m
the body (Figure 5.4B). However, in some inquiline Nicoletiidae the cerci are very short
.
F
our to e
igh

tMa
lpighi
an tu
b
u
l
es are
p
resent. Ten
p
a
i
rs o
f
s
pi
rac
l
es occur an
d
t
h
e tra
-
ch
ea
l
s
y
stem

i
swe
ll d
eve
l
o
p
e
d
com
p
are
d
to t
h
at o
f
M
i
crocor
yphi
a. On eac
h
s
id
eo
f
t
h
e

b
o
dy
a
l
ong
i
tu
di
na
l
trun
kli
n
k
st
h
e trac
h
eae or
i
g
i
nat
i
ng
f
rom t
h
esp

i
rac
l
es, an
d
transverse seg-
mental tracheae unite one side with the other. The female reproductive system includes 2–
7
p
anoistic ovarioles, a spermatheca, and accessory glands. The number of lobes comprisin
g
each testis is
g
reater than in Microcor
yp
hia (ei
g
ht lobes in Le
p
ismatidae, man
y
in Nicoleti
-
id
ae an
d
Le
pid
otr
i

c
hid
ae).
Lif
eH
i
story and Hab
i
t
s
T
hough many Zygentoma resemble Microcoryphia in their general habits, living in
l
eaf litter, under bark, and in other
p
laces with hi
g
h humidit
y
, others are extremel
y
resistan
t
to
d
es
i
ccat
i
on an

dh
ave t
h
ea
bili
t
y
to ta
k
eu
p
water
f
rom t
h
e atmos
ph
ere. A
ll
are ver
y
a
gil
e
i
nsects. Zygentoma are omn
i
vorous or p
h
ytop

h
agous
.
E
ggs are laid singly or in groups, in crevices, etc. Individuals may live for severa
l
y
ears, and as many as 60 molts have been recorded. About a dozen molts occur before
sexual maturit
y
is reached. Because the linin
g
of the s
p
ermatheca is shed at each molt,
f
ema
l
es must mate
b
etween mo
l
ts
i
nor
d
er to
p
ro
d

uce
f
ert
ili
ze
d
e
gg
s. T
h
ema
j
or
i
t
y
o
f
s
p
ec
i
es re
p
ro
d
uce sexua
lly
,ma
l

es
p
ro
d
uc
i
n
g
sta
lk
e
d
s
p
ermato
ph
ores t
h
at are
d
e
p
os
i
te
d
on
t
h
esu

b
strate
f
or
f
ema
l
es to p
i
c
k
up as
i
nM
i
crocoryp
hi
a. However, part
h
enogenes
i
s pro
b
a
bl
y
o
ccurs in a few species where males are very scarce.
P
hylo

g
eny and Classificatio
n
Th
e ear
li
est
k
nown
f
oss
il
z
yg
entoman
is
Rams
d
e
l
epi
d
ion sc
h
usteri
f
rom t
h
eU
pp

er
C
arboniferous of Illinois. This was a large (6 cm long) insect with such primitive features a
s
a full set of long, abdominal, fully segmented leglets, and two pairs of vesicles on the ventral
125
A
PTERY
GO
TE
H
EX
A
PODS
side of abdominal segments 1–7. Extant species fall into four families (LEPISMATIDAE,
N
ICOLETIIDAE, LEPIDOTRICHIDAE, and MAINDRONIIDAE), of which onl
y
the first
t
wo are o
f
an
y
s
i
ze. T
h
ou
gh

most Le
pi
smat
id
ae
li
ve
i
n
li
tter, un
d
er
b
ar
k
, etc., t
h
e
f
am
ily
i
nc
l
u
d
es a num
b
er o

fd
om
i
c
ili
ar
y
s
p
ec
i
es (
f
oun
di
n
b
u
ildi
n
g
s) t
h
at
h
ave
b
een trans
p
orte

d
w
orldwide by human activity, including the common silverfish,
L
epismo
d
es inqui
l
inus
,
and the firebrat, T
h
ermo
b
ia
d
ome
s
tica
.
The former prefers warm and humid environment
s
and is often found in
p
laces such as bookcases, cu
p
boards, and bathrooms. Firebrats, in
contrast,
li
ve

i
n
h
ot,
d
r
y
env
i
ronments,
f
or exam
pl
e,
i
nt
h
ev
i
c
i
n
i
t
y
o
f
fire
pl
aces,

f
urnaces
an
db
o
il
ers, an
di
n
b
a
k
er
i
es. T
h
ey are
hi
g
hl
y res
i
stant to
d
es
i
ccat
i
on. Bot
h

spec
i
es may cause
considerable damage to books, clothing, and foods that contain starch or cellulose, and they
are among the few animals that produce an intrinsic gut cellulase. The Nicoletiidae, which
are distin
g
uished from Le
p
ismatidae b
y
not havin
g
com
p
ound e
y
es, live
p
rinci
p
all
y
in cave
s
or un
d
er
g
roun

d
t
h
ou
gh
some are
i
n
q
u
ili
nes
i
nt
h
e nests o
f
ants an
d
term
i
tes, stea
li
n
g
t
he
h
osts’
f

oo
d
or caus
i
n
g
t
h
e
h
ost to re
g
ur
gi
tate
fl
u
id
sonw
hi
c
h
t
h
e
yf
ee
d.
T
h

e Lep
id
otr
i
c
hid
ae s
h
ou
ld b
e ment
i
one
di
nv
i
ew o
f
t
hi
s
f
am
il
y’s
i
mportant p
h
y
l

o
-
g
enetic position. Prior to 1961 the family was known only as fossils. However, in 1961
Wyg
odzinsk
y
discovered a livin
g
re
p
resentative
,
Tricholepidion gertschi,i
n
California, tha
t
p
ossesses a
l
ar
g
e num
b
er o
fp
r
i
m
i

t
i
ve c
h
aracters. T
hi
ss
p
ec
i
es
i
sc
l
ear
ly
t
h
e most arc
h
a
ic
li
v
i
n
g
a
p
ter

yg
ote
i
nsect
di
scovere
d
to
d
ate an
di
s
lik
e
ly
to
b
es
i
m
il
ar to t
h
e common ancestor
o
f
ot
h
er mo
d

ern groups.
L
i
t
e
r
a
t
u
r
e
A
ccounts o
f
t
h
e
bi
o
l
o
gy
o
f
M
i
crocor
yphi
aan
d

Z
yg
entoma are
p
rov
id
e
dby
De
l
ane
y
(
19
5
7) and Sharov (1966). Keys for identification are given in the papers by Delany (19
5
4)
[British species], Wygodzinsky (1972) [North and Central American Lepismatidae], and
W
ygodzinsky and Schmidt (1980) [Microcoryphia of eastern North America].
Delany, M. J., 19
5
4, Thysanura and Diplura
,
R. Entomo
l
. Soc. Han
db
.I

d
ent. Br. Insects
1
(2)
:
1
–7.
Delan
y
, M. J., 19
5
7, Life histories in the Th
y
sanura
,
Acta Zool.
C
raco
v.
2
:61–
9
0.
S
harov, A. G., 1966
,
B
asic Arthro
p
odan Stock,

P
ergamon Press, Elmsford, NY
.
W
ygo
d
z
i
ns
k
y, P ., 19
6
1, On a surv
i
v
i
ng representat
i
ve o
f
t
h
e Lep
id
otr
i
c
hid
ae (T
h

ysanura)
,
Ann. Entomo
l
. Soc. Am.
54
:6
21–
6
2
7.
W
ygodzinsky, P., 1972, A review of the silverfish (Lepismatidae, Thysanura) of the United States and the Caribbean
W
W
A
rea
,
Am. Mus. Novit.
2481
:
2
6
.
Wyg
odzinsk
y
, P., and Schmidt, K., 1980, Surve
y
of the Microcor

yp
hia (Insecta) of the northeastern United States
and adjacent provinces of Canada
,
A
m. Mus. Novit
.
27
0
1
:17.