Fig. 1

Pictures of female and male from different species of Latrodectus in copula representing the different mating copulatory positions and behaviours observed in females and males (A1 = male abdomen, A2 = male insertion of copulatory organ, A3 = female fangs). Picture A shows Latrodectus hesperus copulating in the posture also observed in L. mactans, where the males rest his abdomen on top of the female’s abdomen during mating. Picture B shows L. hasselti copulating in the posture also adopted by L. geometricus, where the male is in the ‘somersault’ position, placing their abdomen in close proximity to the fangs of the female (A1 = male abdomen, A2 = male insertion, A3 = female fangs). Picture C shows L. mirabilis in copula with the male wrapped in silk by the female, and the female clasping the male’s abdomen near to her fangs. Pictures A and B were taken by Sean McCann, picture C was taken by LB