Studies on the Chromosomes of Mosquitoes1

Abstract

The prophase and anaphase chromosomes of Aedes canadensis Theobald are illustrated, as are the metaphase chromosome complements of 16 other species, as follows: Culex quinquefasciatus Say, C. salinarius Coquillett, C. tarsalis Coquillett, C. territans Walker, Aedes atropalpus Coquillett, A. hendersoni Cockerell, A. triseriatus (Say), A. vexans (Meigen), A. zoosophus Dyar and Knab, Orthopodomyia alba Baker, O. signifera (Coquillett), Haemagogus equinus Theobald, Anopheles pseudopunctipennis Theobald, Culiseta inornata (Williston), Psoropliora longipalpus complex, and Toxorhynchites rutilans septentrionalis (Dyar and Knab). Additional species examined but not illustrated include Culex restitans Theobald. C. erraticus Dyar and Knab, C. coronator Dyar and Knab, Aedes sollicitans (Walker), Uranotaenia syntheta Dyar and Shannon. Psorophora confinnis (Lynch Arribalzaga), and P. discolor (Coquillett). The chromosomes of 16 of these species had not previously been examined. The number 2n = 6 was found in all species studied. Distinctive chromosome complements were found at prophase in O. alba, O. signifera , and T. r. septentrionalis , and at metaphase for Anopheles pseudopunctipeiinis . Except for this last, the chromosome complements of the species examined at metaphase are quite similar. Mitosis in Culex salinarius is illustrated and briefly compared with that previously reported for C. pipiens . These studies were made on brain tissue of prepupae, using the squash technique with aceto-orcein as the stain, and these techniques are discussed. Future work suggested includes studies of salivary gland chromosomes and of meiosis. continued search for unique karyotypes, the use of different tissues and techniques, and studies of mitotic stages other than metaphase.