Like other Rhopalidae, Stictopleurus abutilon has an annual life cycle consisting of an egg followed by five successive nymphal stages before becoming an adult.
Stictopleurus abutilon looks very similar to another Strictopleurus species that occurs in The Netherlands: Stictopleurus punctatonervosus.
In young individuals (nymphs), the two black dots on the back tell you the difference: in Stictopleurus punctatonervosus they are of equal size; in Stictopleurus abutilon one is much smaller than the other.
In adult individuals, Stictopleurus abutilon shows two round (closed) circles (like spectacles) on it shield behind the eyes whereas Stictopleurus punctatonervosus shows here two half circles (not closed).
In addition, Stictopleurus abutilon is always brownish whereas Stictopleurus punctatonervosus is usually more greyish.

1st & 2nd photo: An adult. Crailo, Huizen, The Netherlands, 11 October 2018
3rd & 4th photo: An adult. Landgoed Boekesteyn, 's-Graveland, The Netherlands, 10 September 2019