Sargus cuprarius
Sargus cuprarius, the clouded centurion, is a European species of soldier fly. Description
Body length 6–12 mm. Green eyes with a purple transverse line, upper edge dark or violet. Face and frons  with erect fine black hair; White 
spot at the base of each antenna. Proboscis yellowish brown. Black antennae. A shiny metallic green blue thorax, covered with fine yellow hair ( whitish in male). Wings with distinct darker spots below stigma. Black legs, yellow knees. Abdomen
copper, darker than the thorax with a purple or violet end (male);  violet with a copper base (female)

Biology
Found in open and wooded habitats and  humid places, from June. Larva in decomposing vegetable matter. Distribution
It is found in Western Europe, North and South European Russia, the Caucasus, mountains of Central Asia, Mongolia, and North America. References

External links
Images representing Sargus cuprarius at Bold

Stratiomyidae
Diptera of Europe
Diptera of Asia
Diptera of North America
Flies described in 1758
Taxa named by Carl Linnaeus