A synthesis of gynandromorphy among wild bees (Hymenoptera: Apoidea), with an annotated description of several new cases

We here describe six new specimens of gynanders (i.e. specimens where male and female phenotypic characters occur on the same individual) from distinct families of wild bees (Hymenoptera, Apoidea). The newly described cases include Melitta haemorrhoidalis (Fabricius 1775) (Melittidae), Dasypoda hirtipes (Fabricius 1775) (Melittidae), Anthophora plumipes (Pallas 1772) (Apidae), Bombus monticola rondoui Vogt 1909 (Apidae), Bombus vestalis vestalis (Fourcroy 1785) (Apidae) and Bombus vestalis sorgonis (Strand 1917) (Apidae). Descriptions are accompanied by behavioural observations of gynanders under natural conditions before their capture for two cases. We also list 109 gynanders already described in bees and we interpret the newly described cases along these previous records. The putative origins of gynandromorphy are then discussed in the light of recent advances in the field of sex determination in Hymenoptera.