Sex determination of Propylea quatuordecimpunctata (Coleoptera: Coccinellidae) While working on a project focused on the use of Propylea quatuordecimpunctata for biological control, I needed to determine the sex of several hundreds of individuals. This was done based on the pattern on the head and the shape of its sixth sternite. These characters proved to be troublesome, however, while working, I noticed that the colour of the prosternum is white and contrasting with the sternites of the abdomen in males, while it is black in females. I checked this on several hundreds of specimens and found it to be reliable. This character allows sexing of P. quatuordecimpunctata with relative ease and makes it possible to determine the sex in the field.