Paragus tibialis (Fallén, 1817)
Biology & ecology:
The larva feeds on a range of ground layer and arboreal aphids. In Britain, adults appear to be restricted to dry heathland, where they behave in a very similar way to P. haemorrhous, the two species sometimes occurring together. A very similar species, P. constrictus, has recently been recognised from limestone pavement in the Burren, Ireland (mentioned under P. tibialis in Stubbs & Falk, 1983), and any specimens from limestone pavement in north-west England should be checked for this species.
A rare species of dry heathland in southern Britain, which may be overlooked amongst the much commoner P. haemorrhous. Before the revision by Speight (1978), the only species recognised in this genus in Britain were P. albifrons and P. tibialis, but earlier specimens which have been checked have mostly proved to be P. haemorrhous. Consequently, all pre-1978 records must be considered suspect unless specimens are available and have been re-examined.
Status & conservation:
No obvious trend. The spike in frequency of occurrence in 1998 is due to the Dipterists Forum Summer Field Meeting in Dorset!