Damage - Though they may be a nuisance, soldier flies do not bite and are not known to transmit any diseases. Occasionally larvae accidentally infest the intestinal tract of man or animals. Fortunately, such cases are not common and the maggots pose little real threat. In fact, this species has the beneficial effect of rendering the breeding media less suitable for the production of house flies. Life History - Larvae of black solder flies develop through the winter in decaying organic matter.
Development slows greatly in extremely cold weather.
Depending on temperature and other environmental conditions, pupation occurs in spring and lasts from 9 days to 5 months. Therefore, some adults appear as early as April but many do not emerge until late summer. The larvae seek sheltered, dry locations to pupate. Newly emerged soldier flies mate in flight. Soon afterwards females begin to deposit egg masses near edges of decaying organic matter.