Flies getting filthy: The precopulatory mating behaviours of three mud-dwelling species of Australian Lispe (Diptera: Muscidae)

Lispe (Diptera: Muscidae) is a cosmopolitan genus of predatory flies that inhabit the muddy and sandy surrounds of water bodies. There are more than 163 described species worldwide, many of which are known to exhibit cursorial courtship displays which involve complex visual and vibratory signals. Despite the widespread distribution of these flies and their remarkable courtship displays, the biology and behaviour of most species are entirely unknown. Here, for the first time, we describe the pre-copulatory mating behaviours of three widespread and common Australian species: Lispe sydneyensis, Lispe albimaculata and Lispe xenochaeta. We demonstrate that all three species exhibit entirely unique courtship displays, consisting of complex behavioural repertoires. Importantly, we highlight intrasexual competition in L. sydneyensis, where males engage in competitive dances and combat. We also report female-male aggression in L. albimaculata and L. xenochaeta where females charge and display towards males. These novel mating systems provide unique opportunities to test ecological and evolutionary hypotheses.