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--- Introduction ---
Traps --- Key
--- References
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Identification of the specimens was done under a binocular microscope with the flies in either 70% ethanol or high salt EDTA, depending on the storage media. For those specimens where identification could be made using wing characters only, this was sufficient. For specimens where more detailed characters needed to be examined, they were slide mounted.
Slide mounted specimens were all C. obsoletus group males and also those female species that needed antennal details examined. The specimens were mounted using Aquamount, and dissected so the layout of the slide was as follows:
| Abdomen, ventral side up | Head, 'neck' down and antennae spread |
| Thorax and legs; top of thorax separated and laid beside the rest | Wings both in the same orientation, i.e. one the top side up and the other upsides down. |
These were then examined under appropriate magnification to show details.
The pattern of markings on the wings is the first feature used for species identification.
The main feature used for identification in the females is the sensilla coeloconica on the antennae. The distribution of these vary from species to species.
Males are identified mainly by the features of their genitalia, on the end of the abdomen.
Photographs of all the specimens were taken using a digital camera attached to a microscope. A key was constructed to identify the species found in this study - but only these species. Other midge species are not included.
The effect of the storage media (next page) on the taxonomic features was also investigated.