Springs Can Only Get Better

Monobella grassei.

I've got to admit not putting too much effort into springtail recording recently. Partly this is a hangover from the summer and partly it's because I've been busy with other things, but I do regularly record springtails when I'm out and recently it's become clear that what I think of as the "winter species" are here. Foremost among these is one of my favourites, Monobella grassei, which i've found several times recently.

I can't wait for the leaf litter season to kick off.

Wishing you a Collembola Christmas

With Monobella grassei baubles.

The Science Bit:
Luminescent springtails have been recognized in the families Neanuridae and Onychiuridae (Harvey, E.N. (1952) Bioluminescence. Academic Press; Haneda, Y. (1955) Luminous organisms of Japan and the Far East. The luminescence of biological systems), but the observations are quite limited. It is not clear whether collembolan luminescence is true bioluminescence (endogenous) or accidental due to ingestion of luminous bacteria or fungi. A Japanese springtail Lobelia spp. (Neanuridae) may be self-luminous. This species is ∼3 mm long, found in leaf litter and emits a continuous weak green light from abdominal tubercles. The biological function this luminescence is unknown, but it may be either for defence or sexual communication, since the luminescence is emitted on stimulation and also occurrs in the sexual phase (Lloyd, J.E. (1978) Insect bioluminescence. Bioluminescence in Action, 241-272).

Order Poduromorpha

Identified by a prominent Th1 segment, this group is common and widespread but most species are difficult to identify, hence they are mostly under recorded. Their small size means they are frequently overlooked:

Superfamily Hypogastruroidea
Family Hypogastruridae
Species in this family are difficult to identify, relying on features such as the internal structure of the mouthparts and anal spines. For this reason most people do not bother with them and I have so far made no positive identifications:

11.03.18 ~1mm in Beech leaf litter, roundish mouthcone, 2 anal spines:



Genus Hypogastrura - very short anal spines (c.f. Ceratophysella spp.) plus four-lobed post-antennal organ. 

More that 20 British "species" have been described in this genus, most of which are not valid as they are synonyms, misidentifications or based on a single historic specimen.  In the 2007 AIDGAP key, Steve Hopkin recognized nine UK species, three relatively common and the others rare. Unless microscopic evidence confirming the species is available they should be recorded as Hypogastrura spp. Separating these species is a two step process, first examining the numbers of clavate tenant seta on each tibiotarsus, followed by examination of the mucro, claw and empodium to confirm the species (the AIDGAP key has excellent comparative drawings of these features). The three common species are:

H.manubrialis: 111,  empodium tapers gradually and does not possess a lamella.

H. purpurescens: 232, mucro with bulge and empodium with lamella. 

H. viatica: 233, mucro with large bulge and empodium with lamella. 

Hypogastrura manubrialis

Hypogastrura manubrialis leg 3 - one clavate tenant seta

Hypogastrura manubrialis mucro

Superfamily Neanuroidea
Family Brachystomellidae
Genus Neanura - no furca - springless springtails:
Neanura muscorum. A very common blueish-purple springtail, usually found under bark on decaying wood. The eyes are highly distinctive with 3+3 ocelli. Pointed mouthcone, it lacks a furca. Easy to identify - the only UK species in this genus.






Genus Monobella
Monobella is a contraction of mono+lobella and refers to the single (transverse) lobe of the last body segment - c.f. Bilobella (2 posterior lobes).

Monobella grassei. A distinctive orange springtail with long body setae:







Family Poduridae
Genus Podura - Podura aquatica.
To follow.