First record of gynandromorphy in Andrena florivaga and an additional case in Nomada lathburiana from Germany (Hymenoptera, Apoidea)

Rare developmental anomalies can provide valuable insights into the mechanisms of sex differentiation, particularly when they manifest in clearly defined morphological patterns. In this study, we describe the first recorded gynandromorph of Andrena florivaga and a further gynandromorphic specimen of Nomada lathburiana from Germany. The Andrena florivaga specimen shows a predominantly bilateral display of sexually dimorphic traits, with male structures largely restricted to one side of the body while female traits dominate the opposite side; the head and forelegs represent entirely the female state. This pattern continues across the mesosoma, legs, and metasoma and involves both secondary sexual characters and terminal structures. The second specimen was identified as Nomada lathburiana and exhibits a mainly bilateral separation of male and female morphology, particularly in the tergites, sternites, mesosomal pubescence, and leg coloration. However, within certain body regions the assignment of traits alternates and transitions become indistinct, resulting in a bilateral gynandromorph with mosaic elements. The first recorded case of gynandromorphy in Andrena florivaga , together with a further morphologically distinct specimen of Nomada lathburiana , expands the known range of gynandromorphic phenotypes in wild bees and highlights the value of such anomalies for understanding sex differentiation and morphological pattern formation in Hymenoptera.