PROC. ENTOMOL. SOC. WASH. 95(3), 1993, pp. 377-382 BIOLOGY OF HYADINA ALBOVENOSA (DIPTERA: EPHYDRIDAE), A CONSUMER OF CYANOBACTERIA B. A. FooTE Department of Biological Sciences, Kent State University, Kent, Ohio 44242. Abstract. —Information is presented on the life cycle and larval feeding habits ofHyadina albovenosa Coquillett, a common and widely distributed shorefly species of the subfamily Hyadininae and tribe Hyadinini. Larvae were found in nature only on soil-inhabiting colonies of Anabaena, a genus of Cyanobacteria (blue-green algae). Laboratory feeding tests indicated that the larvae can develop on a wide mixture of Cyanobacteria and even on such true algae as the diatom Navicula pelliculosa and the euglenophyte Euglena gracilis. Under laboratory conditions, the life cycle was completed in 18-19 days if A. variabilis served as the larval food. Eight generations a year can be produced in northeastern Ohio. The larval food preference of H. albovenosa is contrasted and compared with those of other species of Hyadininae that utilize soil-inhabiting Cyanobacteria. Key Words: Insecta, Diptera, Ephydridae, biology, Hyadina albovenosa The superfamily Ephydroidea, consisting of 5 families (Curtonotidae. Camillidae, Drosophilidae, Diastatidae, Ephydridae), contains some 4000 species and has a worldwide distribution (McAlpine 1989). Undoubtedly the larger and better known families biologically are the Drosophilidae and Ephydridae whose larvae commonly have microphagous habits. Many species of Drosophilidae occur in forested habitats where they consume heterotrophic micro-organisms, particularly yeasts (Ferrar 1987), whereas many species of Ephydridae occur in open, wetland habitats where their larvae feed on a wide variety of algae (Foote 1977, 1979). Two of the more interesting assemblages of phycophagous Ephydridae are in the tribes Hyadinini {Axysta, Hyadina, Lytogaster, Microlytogaster, Pelina, Pseiidohyadina) and Philygriini (Nostima, Philygria) of the sub-family Hyadininae (Mathis and Zatwar-nicki 1990). Larvae of species of these two tribes seemingly are specialized for the con-sumption of Cyanobacteria (blue-green al-gae) (Foote 1977). The larval feeding habits of Lytogaster excavata (Sturtevant and Wheeler), Nostima approximata Sturtevant and Wheeler, and Pelina truncatula Loew have been elucidated in earlier papers (Foote 1981a, b, 1983). This paper discusses the larval feeding habits of Hyadina albovenosa Coquillett and presents data on its utilization of different microbial species. Trophic resource parti-tioning among certain species of Hyadini-nae is also discussed. Materials and Methods All field work was carried out in north-eastern Ohio in Portage County. The lab-oratory rearings and larval feeding tests were maintained in an environmental chamber programmed to give a photoperiod of 15L: 9D and a temperature of 22°C (+ 1°C). Most of the algae used in the feeding tests were obtained from the University of Texas Cul-ture Collection of Algae (Starr 1978). Spe-
BioStor
