Lonchoptera lutea Panzer, 1809. (Lonchopteridae). Yellow Spear-winged Fly larvae found at Ribbesford Woods, Worcestershire
The 28th March 2015 meeting of the Wyre Forest Study Group at Ribbesford Woods was entitled 'Early Insects on Blossom' but a late spring hampered our efforts and the expected sallow blossom was not out. Our attention was turned to other areas and grubbing in the leaf litter provided two strange woodlouse-like larvae some 4 mm long with long hair-like bristles at grid reference SO784721 (01, 02). At first their identity was a mystery but Coleoptera or Diptera larvae were on the list. I took one home to photograph and posted the image around to group members. It was a pupa and Mike Blyth suggested a hoverfly was possible. Further looking into Diptera revealed an image of a Lonchoptera fly larvae in a rather old but useful book (Lyneborg 1968). Internet on-line checking confirmed it was a Lonchoptera fly, possibly L. lutea, the commoner species of this group. Four days after the field meeting the pupa I had taken home hatched and a rather small (3mm) but quite interesting fly emerged (03, 04).
The fly appears to be quite common but the larvae are very unusual and hopefully of some interest to readers. To quote from the internet; Lonchoptera are tiny to small (2-5mm), slender, yellow to brownish-black bristly Diptera. Their common name refers to their subacute (pointed) wings which have a distinct and sexually dimorphic venation. The larvae are dorsally flattened, with two pairs of head bristles, and feed on rotting vegetable matter.
Our editor Harry Green provided a reference paper to the species by John Lubbock dated 1862. (Lubbock 1862). Quite how Harry manages to find such information is a mystery? The paper gives a very detailed account of the larvae and development of the fly, including an illustrated plate of the larvae. I was drawn to Lubbock's description of the larvae (05):
The Royal Entomological Society (RES) key on the Immature Stages of British Flies is also available on line as a download but without the illustrations that appear in the printed version (Smith 1989). Thanks to Harry Green for providing this information.
Lubbock, J. 1862-64. On the development of Lonchoptera. Transactions of the Entomological Society of London. Third series volume 1:338-344.
Lyneborg, L. 1968 Field and Meadow Life. (English Edition, A. Darlington). Blandford Press.
Internet information at http://en.wikipedia.org/wiki/Lonchoptera
RES Key to Immature Stages of British Flies; http://www.royensoc.co.uk/sites/default/files/Vol10_Part14_MainText.pdf (no illustrations).
Smith, K. V. G. 1989. An introduction to the immature stages of British flies: Diptera larvae with notes on eggs, puparia and pupae. Handbooks for the identification of British Insects. Volume 10, part 14. Royal Entomological Society of London.
01. Lonchoptera lutea pupa Ribbesford Wood. John Bingham
02. Lonchoptera lutea pupa Ribbesford Wood. John Bingham
03. Lonchoptera lutea Ribbesford Wood. John Bingham
04. Lonchoptera lutea Ribbesford Wood. John Bingham
05. Extract from Lubbock’s 1862 paper on the development of Lonchoptera.