Evidence of Monandry in a Mosquito (Sabethes cyaneus) with Elaborate Ornaments in Both Sexes Sandra H. South & Göran Arnqvist Revised: 22 April 2008 / Accepted: 25 June 2008 / Published online: 30 July 2008 # Springer Science + Business Media, LLC 2008 Abstract Despite the benefits of multiple mating to females many mosquitoes appear to be monandrous. Members of the mosquito tribe Sabethini are unique among the mosquitoes for they possess iridescent scales and elaborate ornaments in both sexes. Additionally, this tribe boasts the only reported cases of courtship display within the mosquitoes. Due to these singular traits and behaviors, we predicted that members of this tribe have a different mating system with relatively high female mating rate. We tested this prediction in the ornamented mosquito Sabethes cyaneus. Contrary to our prediction, however, females were monandrous throughout their lifetime and multiple gonotrophic cycles. We discuss the possible implications of monandry on the evolution of sexually homologous ornaments, with particular consideration of mutual mate choice. Keywords Mating rate . mating system . polyandry . signal . sexual selection . Diptera Introduction Mosquitoes in the tribe Sabethini (Diptera: Culicidae) possess a suit of characteristics that make them unique among the mosquitoes: diurnal activity, a greater reliance on vision (Shannon 1931; Haddow and Corbet 1961; Hancock et al. 1990a), and mating on a substrate (Hancock et al. 1990a). Most notable are the colorful iridescent scales that cover much of the body of these mosquitoes (Judd 1996). This coloration is complemented with elaborate paddle-like ornaments on the legs of some species (henceforth referred to simply as ‘paddles’) (Harbach 1991). In those species with the most elaborate paddles both males and females express these ornaments and the degree of sexual dimorphism is relatively limited, although there are some species in which the paddles are relatively small in males and absent or reduced in females (R. Harbach, personal communication). The lack of pronounced sexual dimorphism in J Insect Behav (2008) 21:451–459 DOI 10.1007/s10905-008-9137-0 S. H. South (*) : G. Arnqvist Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden e-mail: sandra.south@ebc.uu.se