Jordanathrix nr superba
Dicyrtoma fusca is a small globular springtail (1-2mm) which varies considerably in colour from a dark maroon red to a paler yellow form, the mottled patterning also varies:
The above (commonest) forms are known as Dicyrtoma fusca var.1. There is also a much rarer melanistic dark (almost black) form, Dicyrtoma fusca var.2 (not known from VC55), and a leucistic form with dark ocelli on a pale eyepatch, Dicyrtoma fusca var. rufescens:
A common species found throughout Britain. The name is of this species is confusing - some D. minuta specimens grow bigger than D. ornata. Typically pale gold and less pigmented than D. ornata (dorso-anterior pigmentation lacking in particular). Similar to D. ornata, there is a long, narrow pigment streak on the rear of the abdomen. Facial interocular pigmentation:
In D. minuta there are 2 dark spots: one on top of the head and one just below the antennal bases.
In D. ornata these spots are interconnected by a brown stripe.
The historical records for a number of groups of springtail are hopelessly confused. These include Entomobrya intermedia/nivalis and also Dicyrtomina ornata/saundersi. This species has been frequently identified by the large rectangular patch of dark pigment on the abdomen, but this species is very variable in pattern and colour. Key features:
- No sharp colour change along the length of the antennae
- Dorsal colour of the 6th abdominal segment (the dorsal anal valve) is dark:
- Distinct colour change at the joint of sections 2 and 3 of the antennae
- Dorsal colour of the 6th abdominal segment (the dorsal anal valve) is light:
Jordanathrix nr. superba
This species resembles but is distinct from Dicyrtomina superba from New Zealand. Thought to be a relatively recent introduction to the UK, first recorded about 10 years ago. This species has a patch of dark pigment on the abdomen and is similar in appearance to D. ornata but the colour of the eyepatch is much paler (with dark ocelli) than the all-dark eyepatch of D. ornata: