Medical and Veterinary Entomology (2016) 30, 14–20 doi: 10.1111/mve.12143 Swarming and mating activity of Anopheles gambiae mosquitoes in semi-field enclosures D. A C H I N K O 1,2† , J. T H A I L A Y I L 3 , D. PATON 4 , P. O. M I R E J I 5,6 , V. TALESA 4 , D. M A S I G A 1 and F. C AT T E R U C C I A 3,4,7 1 Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya, 2 Department of Biochemistry and Molecular Biology, Egerton University, Njoro, Kenya, 3 Department of Life Sciences, Imperial College London, London, U.K., 4 Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Universita degli Studi di Perugia, Perugia, Italy, 5 Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya, 6 Division of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, U.S.A. and 7 Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, U.S.A. Abstract. Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) is the major Afro-tropical vector of malaria. Novel strategies proposed for the elimination and eradication of this mosquito vector are based on the use of genetic approaches, such as the sterile insect technique (SIT). These approaches rely on the ability of released males to mate with wild females, and depend on the application of effective protocols to assess the swarming and mating behaviours of laboratory-reared insects prior to their release. The present study evaluated whether large semi-feld enclosures can be utilized to study the ability of males from a laboratory colony to respond to natural environmental stimuli and initiate normal mating behaviour. Laboratory-reared males exhibited spatiotemporally consistent swarming behaviour within the study enclosures. Swarm initiation, peak and termination time closely tracked sunset. Comparable insemination rates were observed in females captured in copula in the semi-feld cages relative to females in small laboratory cages. Oviposition rates after blood feeding were also similar to those observed in laboratory settings. The data suggest that outdoor enclosures are suitable for studying swarming and mating in laboratory-bred males in feld-like settings, providing an important reference for future studies aimed at assessing the comparative mating ability of strains for SIT and other vector control strategies. Key words. Anopheles gambiae, genetic control, malaria, mating, semi-feld, sterile insect technique, swarming, vector control. Introduction Anopheles gambiae mosquitoes are the major vectors of human malaria, a disease that causes considerable morbidity and mortality in the tropics (Snow et al., 2005). According to recent World Health Organization (WHO) estimates, there were 216 million cases of malaria in 2010 and more than 600 000 Correspondence: Daniel Masiga, Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya. Tel.: + 254 20 863 2070; Fax: + 254 20 863 2001; E-mail: dmasiga@icipe.org and Flaminia Catteruccia, Department of Immunology and Infectious Diseases, Harvard School of Public Health, 886 Huntington Avenue, Boston, MA 02115, U.S.A. Tel.: + 1 617 432 1773; Fax: + 1 617 432 8077; E-mail: fcatter@hsph.harvard.edu † Present address: Sydney Brenner Institute for Molecular Bioscience, University of Witwatersrand, Johannesburg, South Africa. people died of this disease, most of whom were children under 5 years of age in sub-Saharan Africa (Murray et al., 2012; WHO, 2014). The management of Anopheles mosquitoes using various classes of insecticide has been hampered by several challenges, including widespread cross-resistance to insecticides (Chandre et al., 1999; Enayati & Hemingway, 2010). This presents a real and immediate threat to the effcacy of otherwise successful 14 © 2015 The Royal Entomological Society