Microdon myrmicae Schönrogge, Barr, Wardlaw, Napper, Gardner, Breen, Elmes & Thomas, 2002
The 'Microdon mutabilis' of earlier works (e.g. Stubbs & Falk 1983) was split by Schonrogge et al. 2002, into two species M. mutabilis and M. myrmicae and most of the records formerly ascribed to M. mutabilis are believed to relate to M. myrmicae.
Biology & ecology:
The larva is associated with ant nests, and at the moment the principal host appears to be Myrmica ruginodis which is a widespread and common ant that favours cooler temperatures than many others within the genus. There is some evidence that adult Microdon from particular ant nests may stand the greatest prospect of breeding successfully if they lay their eggs in association with the original host colony, thereby suggesting a degree of sub-speciation linked to the characteristics of individual ant colonies.
This seems to be a highly localised species that occurs in southern and western England and Wales, including Cornwall, Devon, Hampshire and Surrey, mid-Wales and Cumbria.
Status & conservation:
The frequency of occurrence plot is for 'M. mutabilis sensu lat.' Recent advances in finding the larvae have shown that it is more widespread than was previously thought. The rising trend in frequency of occurrence therefore reflects better recording.