I have a female Sargus which is hard to place as between S. cuprarius and C. irridatus. The text in the Soldierflies book accepts there will be problems and identification can be confirmed only via the genitalia. When I examined this female she proved to have a clutch of six eggs in the end of the addomen. Apart from i/d, therefore, I'd welcome guidance on whether by careful conservation I could keep the eggs viable through to the adult stage.
Anthony Bainbridge