Twee gynandromorfen van de rotsbehangersbij (Megachile pilidens)

The author describes two gynandromorphs of Megachile pilidens from the previous collection of G. van der Zanden, found in the NBC Naturalis in Leiden. He explains the origin of these gynandromorphs based on the information about the sex determination of Hymenoptera and the embryology of insects. He criticizes two recent articles where embrological components are missing in explanations of gynandromorphs.