|Leaf mine in Polygonatum multiflorum - the arrows indicate small groups of feeding larvae|
|Larva of Parallelomma paridis. The head is to the bottom of the photo (note the black mouthparts) and the pair of posterior respiratory processes (PRPs) can be seen at the rear. Yellow-green gut contents are also visible.|
The mines of this genus start near the eggs which are laid in small groups with the larvae then feeding communally.
|Empty eggs of P. paridis - note the elongate shape and longitudinal ridges. The slit to the right appears to be the entrance to the mine|
|A small group of P. paridis larvae feeding together in the leaf mine. The arrows indicate the small, black, hooked mouthparts.|
As well as muscle contractions, movement through the narrow mine is aided by the additional grip created by rings of tiny spikes on the surface of the larva, running around the front edge of each segment.
|The head of the P. paridis larva - note the rings of tiny black spikes around the front of each segment. A pair of 'eye-lash' shaped tufts (probably with a sensory function) can also be seen, if a little out of focus, on the first segment.|
Pupation, with the associated hardening and darkening of the cuticle, appears to begin with the PRPs and then progress inwards from both ends of the larva. So, I would like to finish with a series of images showing the progress of pupation in this species and some of the structures of the pupa itself.
|Larva of P. paridis with the PRPs having darkened as pupation is about to begin.|
|Larva of P. paridis showing partial pupation.|
|Pupa of P. paridis (approx 4mm long)|
|Head of P. paridis pupa showing the 'eye-lash' shaped tufts also seen in the larva above|
|Rear of P. paridis pupa showing the pair of PRPs and several smaller spines|
|Rear of P. paridis pupa showing the pair of PRPs and rings of small spikes around the articulations of segments.|
|Rear of P. paridis pupa showing the pair of PRPs and smaller lateral spines|
Chandler, P.J. (1998). Checklists of insects of the British Isles (new series) part 1: Diptera. Handbooks for the Identification of British Insects 12(1): i-xx; 1-234.
Nelson, M. (1990). Observations on the biology and status of British dung flies of the genus Parallelomma Becker (Dipt., Scathophagidae). Entomologist's Monthly Magazine 126: 187-189.
Pitkin, B., Ellis, W., Plant, C. & Edmunds, R. (2012). The Leaf and Stem Mines of British Flies and Other Insects: Parallelomma vittatum (Meigen, 1826) [accessed 05/06/2012].
Smith, K.G.V. (1989). An introduction to the immature stages of British flies. Handbooks for the Identification of British Insects 10(14): 1-280.