Axenic culture of Lambornella clarki (Ciliophora: Tetrahymenidae), an endoparasite of Aedes sierrensis (diptera: Culicidae)

Abstract

Lambornella clarki (Ciliophora: Tetrahymenidae) is a facultative parasite of the western treehole mosquito Aedes sierrensis (Diptera: Culicidae). In response to waterborne substances produced by larval mosquitoes, free-living trophonts of L. clarki are induced to form parasitic theronts that attach to and infect the larvae. Reported here are methods for establishing and maintaining axenic and monoxenic trophont cultures, determining cell growth rates, and inducing theront formation of L. clarki. Results from laboratory experiments indicate that these methods provide for reliable cell growth and induction of theronts. After 19 months in continuous axenic culture, theront formation by trophonts exposed to ground A. sierrensis larvae declined, while moderate levels of theronts (16%) were still obtainable from trophonts exposed to water previously containing larvae. Highest cell densities and theront production were achieved from trophonts cultured in media that also contained Streptomyces sp.