Functional morphology of the male genitalia and copulation in lower Hymenoptera, with special emphasis on the Tenthredinoidea s. str. (Insecta, Hymenoptera, ‘Symphyta’)

A general description of the male reproductive organs of lower Hymenoptera is given. The terminology of the male genitalia is revised. The male external genitalia of Tenthredo campestris are treated in detail as a specific example of the morphology. The interaction of the male and female parts during copulation is described for Aglaostigma lichtwardti . The possible function of sclerites and muscles of the male copulatory organ of Tenthredinoidea s. str. is discussed. Additional observations on morphology and function made in non‐tenthredinoid lower Hymenoptera are included. The assumption that the gonomaculae act as suction cups is confirmed for the first time. The evolution of obligate and facultative strophandry is discussed. The stem species of all Hymenoptera was probably orthandrous and facultatively strophandrous.