Hadrodemus noualhieri

Appearance

The species is very similar to its congener Hadrodemus m-flavum, which has a much wider distribution range to the north an east in Europe. Differences often quoted include:
The length of the first antennal segment vs. the length of the head, but it is probably better to use this vs the width of the head with different quota for males and females: See Wagner (1966).
The body of noualhieri is more slender, mostly parallel-sided (especially in males), vs a bit wider ovally in m-flavum
The differences in male genitalia are quite subtle, but well described by Wagner (1966)
Colour differences often quoted will have noualhieri with darker orange-yellow hues as thinner pale lines on pronotum and fore wings vs generally paler yellow with broader pale lines on m-flavum, but there is considerable variability in this.
Sometimes the colour of the legs is quoted as more darkish red in m-flavum vs black in noualhieri, but looking at series of specimen this is not a reliable character (both black legs in m-flavum and reddish legs in noualhieri do occur).
One possibly useful character brought forward by Wagner is that the tip (and part of the outside margin) of the cuneus is black in noualhieri and (usually?!?) pale in m-flavum.

Naming

Hadrodemus noualhieri was originally described as Grypocoris noualhieri by Reuter in 1896. In 1966 Wagner had a chance to analyze a series of specimen and convincingly argued that the species was much more similar to Hadrodemus m-flavum and hence should be transferred to the same genus. He also showed that characters to separate the two genera, used to that date, did not hold their ground and redescribed the diagnosis for the two genera.

Distribution

In Europe it's known range is limited to the Iberian peninsula