Sculptural patterns on the thorax of the four UK species
The photographs here are kindly provided by Villu Soon. They show the sculpture of the thorax of the four UK species. These photos should help to clarify the descriptions given in Morgan (1984).
Hedychridium coriaceum
"Punctuation of pronotum, mesoscutum and mesoscutellum coriaceous with distinct rugae formed by alignment of puncture margins."
Hedychridium roseum
Showing closely packed punctures which are adjacent and not separated by broad smooth spaces. 1, Compare to H. cupreum, then 2, compare to H. coriaceum and H. ardens.
Hedychridium ardens
"Punctuation of pronotum, mesoscutum and mesoscutellum separated, without rugae formed by alignment of puncture margins."
Hedychridium cupreum
"Mesoscutum with widely scattered punctures, broad spaces between glassy smooth; mesoscutum conspicuously less densely and coarsely sculptured than propodeal dorsum."