Springtail genera/species to
know in the
Entomobryomorpha
Peter Shaw
Introduction
• Entomobryomorpha are “typical”
springtails and generally have a well
developed furca. If you see some in your
garden or pitfall traps without a lens it’s
usually this group!
• They are further subdivided into those
where body segments are about equal
length (Isotomidae = equally cut), and
those where abd 3 or 4 is enlarged
reflecting large muscles (Entomobryidae).
Equal length
Unequal length – abd 4 enlarged
Genera in the Entomobryidae
• Generally large with ciliated
macrochaetae and well developed
furca. Some have scales.
Tomocerus, etc
•
It used to be simple – a very big scaly springtail with ant3 elongated and
annulated was Tomocerus, and for me always will be. (6 eyes, oddly).
Then someone removed the biggest of all, T. longicornis, to the genus
Pogonognathellus.
The furcula lies in a
groove in the abdomen
Tomocerus sp – note long ant. III. In this
genus ant3 hardly tapers at all and hs no
scales.
6 eyes on
Tomocerus
Tomocerus minor and vulgaris
Tomocerus minor, <=
4.5mm with an irridescent
blue sheen. I found this
all over St Helena,
presumably introduced by
humans.
T. minor was once
“tridentifera” due to distinctive
tridentate teeth at base of
furca.
T. vulgaris looks similar, but
has simple teeth here.
Both lack empodial
filament
Pogonognathellus longicornis
(<= 6mm, with <=8mm antennae – our largest
springail). Note lyre-like curving of antennae,
diagnostic of the species. Blow on them in the field!
This species is easily told from Tomocerus by
microscopic examination of the foot – the empodium
has a long filament. Also antenna 3 tapers and carries
micro-scales. Formally the labium has a complex
ciliated field (‘bearded jaw’), along with the scarce
species P. flavescens).
Pogonognathellus
longicornis (next
to Megalothorax
minimus)
Entomobryas
These are hairy but scale-less, often boldly
marked, active collembola running around on bark
or posts.
E. nivalis
E. albocincta –
mainly in
canopy
E. intermedia
E. nicoleti
E. multifasciata
- stripy!
Note the paired spots)
Lepidocyrtus
Lepido = scaly, and they are! The scales are so thick on
some as to give them an iridescent sheen, a bit like living
drops of mercury. They jump well too.
Lepidocyrtus
cyaneus –
very common
in litters and
on surfaces.
<=1.5mm.
Lepidocyrtus
probably lignorum
(based on rainbow
patterns on ant1-2
and legs)
Lepidocyrtus
lanuginosus–
very common in
canopy
communities,
also litters.
Lepidocyrtus
paradoxus –
note the
prominent Th2.
Orchesella
As adults these are easily spotted by the 2 basal
antennal segments being doubled, giving the
appearance of 6 segments.
Orchesella cinta
There are 2 big very common species: Orchesella
cinta (= “belted”, white abd2 vs black abd3), and O.
villosa (an Entomobrya-like pattern but huge hairs).
Another 5 species (?), probably scarce, ID by colour
pattern.
O. villosa
Genera in the Isotomidae
• Generally smaller with smooth
macrochaetae [not all] and shorter
furca; never any scales.
Parisotoma notabilis
• Everywhere all the time, all over europe
too.
0.1-2.0 mm long, the giveaway is the square dot of an eyepatch with 4
ocelli.
Isotoma, s. lat.
This genus has been split down into Isotoma, Desoria, and Paraisotoma. They all
look pretty similar, and a few of species have the habit of turning up in ridiculously
disparate habitats. About 10 other species too. Big Isotomas have ciliated
macrochaetae and can be mistaken for entomobryids.
Isotoma viridis (and I. anglicana, and I.
caerulea). These 3 are told apart by
ridges (1 or 2) on the manubrium and
hairs (2 or 3) at the base of the dens.
Collectively ubiquitous. Viridis means
green, but can also be shades of
red/brown/grey.
Isotoma viridis, 3mm
Parisotoma notabilis –
distinctive square eye
patch / 4 eyes. Clonal? 4
gene lines in UK (at least!)
Vertagopus
Take a small grey/brown Isotoma, give it clubbed hairs (tenant setae) on its legs
and make it a keen tree climber, and you’ve got a Vertagopus! 2 species, both
common but only near the ground in low habitats like lichen heath.
Vertagopus arboreus.
These have a thick waxy
cuticle, that can give good
iridescence in the correct
lighting.
(Flickr: Andrew Robertson)
Vertagopus cinerea is browner with a shorter furca.
Take an Isotoma viridis -like animal, give it trichobothria on its
abdomen and a love of water, and you have Isotomurus. (The
mucro looks a bit different too).
trichobothria
Isotomurus palustris –
exceedingly common
Isotomurus maculatus
4 mucronal teeth
Tetracanthella
I associate the upland species in this genus with my PhD in Northumberland;
Tetracanthella wahlgreni an ice age relic. Blue-black with 4 orange spines on
abd 6. Have since collected from pennines and Cairngorms – am always
pleased to see them. Other species in moss on walls / trees but always
scarce.