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 Oboňa J., Horvat B., Novikmec M., 2014: First record of Wiedemannia (Chamaedipsia) mikiana (Diptera: Empididae) from Slovakia. (Prvý nález druhu Wiedemannia (Chamaedipsia) mikiana (Diptera: Empididae) na Slovensku). 2 pp. Klapalekiana 50(3-4): 235-236.

 Oboňa J., Ježek J., 2012: First records of dendrolimnetic moth flies (Diptera: Psychodidae) from Slovakia. Prvonálezy dendrotelmovch kútoviek (Diptera: Psychodidae) zo Slovenska. 9 pp. (in English). Klapalekiana 48(3-4): 279-287.

 Ode P. E., Matthysse J. G., 1967: Bionomics of the face fly, Musca autumnalis DeGeer. 87 pp. 

 Offenberger M., Klarenberg A. J., 1997: Hymenopteran parasitoids of Drosophila breeding in decaying herbage (Diptera: Drosophilidae). 9 pp. [DIP 2448] Nachrichtenblatt der Bayerischen Entomologen 46(1/2): 11-19.

 Ohnesorge B., 1971: Beobachtungen über den Einfluß von Außenfaktoren auf die Fangergebnisse in Fritfliegenfallen. (Oscinella frit. L., Dipt., Chlorop.). 12 pp. (in German). Zeitschrift für Angewandte Zoologie 58: 105-116.

 Ohnishi S., Kawanishi M., 1981: The sexcomb of Drosophila simulans: geographical variation and genetic analysis. 8 pp. Kontyu, Tokyo 49(1): 37-44.

 Ohno S., Haraguchi D., Kohama T., 2006: New host and distribution records of the fruit fly, Bactrocera scutellata (Hendel) (Diptera: Tephritidae), in southwestern Japan, and a case of infestation of the species on cucumber fruits at Okinawa island. 3 pp. Japanese Journal of Entomology (N.S.) 9(1): 7-9.

 Ohno S., Tamura Y., 2008: First detection of the fruit fly Bactrocera synnephes (Diptera: Tephritidae) on Iriomote Island , south-western Japan. 6 pp. Entomological Science 11(1): 105-110.

 Ohwaki A., Nakamura K., 2010: Population persistence of the parasitoid fly Zaira cinerea (Fallén) (Diptera: Tachinidae) utilizing multiple host carabid beetles with different seasonality and quality. 8 pp. Entomological Science 13(3): 280-287.

 Oikawa A., Mori N., Kimura M. T., 2006: Comparison of oxygen consumption in drosophilid flies from different climates. 8 pp. Entomological Science 9(4): 347-354.

 Okada I., 1938: Einige fungivoriden vom Daisetsu-Gebirge in Hokkaido (Dipt., Nematocera). 8 pp. 

 Okada T., 1973: Drosophilidae and Diastatidae from Mongolia (Diptera). 9 pp. 

 Okada T., 1974: Drosophilidae (Diptera) from Korea. 7 pp. Ann. Hist.-nat. Mus. Nat. Hung. 66: 269-275.

 Okada T., 1975: The oriental Drosophilids breeding in flowers. 8 pp. Kontyu, Tokyo 43(3): 356-363.

 Okada T., 1978: Pseudostegana, a new subgenus of the genus Stegana Meigen (Diptera, Drosophilidae. 8 pp. Kontyu, Tokyo 46(3): 392-399.

 Okada T., 1980: A revision of the genera Hypselothyrea de Meijere and Tambourella Wheeler (Diptera, Drosophilidae). 16 pp. Kontyu, Tokyo 48(4): 501-516.

 Okada T., 1980: Synhospitalic evolution of the genus Drosophilella Duda (Diptera, Drosophilidae), with description of a new species from Okinawa and Taiwan. 8 pp. Kontyu, Tokyo 48(2): 218-225.

 Okada T., 1992: New or Little Known Species of the Genera Liodrosophila Duda and Sphaerogastrella Duda (Diptera, Drosophilidae) from Papua New Guinea and S. E. Asia. 12 pp. 

 Okada T., Nishiharu S., 1981: A new species of the subgenus Scaptodrosophila of the genus Drosophila (Diptera, Drosophilidae) visiting flowers in Japan. 4 pp. Kontyu, Tokyo 49(3): 422-425.

 Okáli I., 1986: List of the type specimens in the collections of the Slovak national museum – institute of natural history, Bratislava: Insecta, Diptera. 2 pp. 

 Okáli I., Labuda M., 1986: History of the research of malaria in Slovakia. 3 pp. (in Slovakian). 

 Okamoto T., Macgowan I., Su Z. H., 2012: Predation on the pollinating fig wasp of Ficus erecta by larvae of Silba sp. (Diptera: Lonchaeidae). 6 pp. Entomological Science 15(3): 288-293.

 Okazawa T., Miyagi I., Yong H. S., 1992: Oviposition and Eggs of Armigeres (Leicesteria) flavus (Diptera, Culicidae). 5 pp. 

 Okazi I., Labuda M., 1988: Dejiny výskumu malárie na Slovensku. 18 pp. 

 Okely E. F., 1974: Description of the puparia of twenty-three British species of Sphaeroceridae (Diptera, Acalyptratae). 16 pp. 

 Oldenberg L., 1901: Blepahrocera fasciata Westw. (Dipt.). 8 pp. 

 Oldenberg L., 1904: Aus der „Zeitschrift für Hymenopterologie und Dipterologie“. Heft 2, 1904. Die Gattung Saucropus Lw. (Dipt.). 16 pp. 

 Oldenberg L., 1914: Beitrag zur Kenntnis der europäischen Drosophiliden (Dipt.). 42 pp. 

 Oldenberg L., 1914: Berichtigung zu meiner Drosophilidenarbeit. 1 pp. 

 Oldenberg L., 1916: Einige Dolichopodiden meiner Ausbeute (Dipt.). 12 pp. 

 Oldenberg L., 1917: Die Rhamphomyien (Dipt.) des Wiener Hormuseums. 14 pp. 

 Oldenberg L., 1922: Bemerkungen über die ehemaligen Drosophiliden (Dipt.). 2 pp. 

 Oldenberg L., 1923: Neue Acalyptraten (Dipt.) meiner Ausbeute. 13 pp. Deutsche entomologische Zeitschrift 1923: 307-319.

 Oldenberg L., 1924: Die bei Eriopeltis lichtensteini schmarotzende Leucopis (Dipt.). 3 pp. 

 Oldenberg L., 1924: Zur Kenntnis der Asiliden-Gattung Lasiopogon (Diptera). 8 pp. [M15] [M40] 

 Oldenberg L., 1927: Anthomyza fasciipennis sp. n. (Dipt.). 3 pp. 

 Oldengerg L., 1920: Dipteren aus den Alpen. 14 pp. 

 Oldroyd H., 1937: Bombyliidae from Chile and Western Argentine (Part II). 11 pp. 

 Oldroyd H., 1939: Chrysopilus nubecula Fallén (Diptera: Rhagionidae), a species new to Britain. 2 pp. 

 Oldroyd H., 1949: Diptera. Introduction, and keys to families. 4 pp. 

 Oldroyd H., 1955: A wingless Dolichopodid (Diptera) from Campbell Island. 4 pp. 

 Oldroyd H., 1960: Diptera Asilidae. Mission zoologique de l’I.R.S.A.C. en Afrique orientale. (P. Basilewsky et N. Leleupt, 1957). XXIX. 5 pp. 

 Oldroyd H., 1960: Some Tabanidae (Dipt.) from Madagascar. 6 pp. [M42] 

 Oldroyd H., 1961: Ergebnisse der Deutschen Afghanistan-Expedition 1956 der Landessammlungen für Naturkunde Karlsruhe. 4 pp. 

 Oldroyd H., 1963: The 3rd Danish Expedition to Central Asia. Zoological results 32. Asilidae (Insecta) from Afghanistan. 5 pp. [M42] 

 Oldroyd H., 1966: Notes on Coenomyia Latreille (Diptera: Coenomyiidae). 10 Figs., 11 pp. [B18] 

 Oldroyd H., 1966: Notes on Coenomyia Latreille (Diptera: Coenomyiidae). 10 Figs., 11 pp. [DIP 2473] [B18] [M15] 

 Oldroyd H., 1968: Contributions a la connaissance de la faune entomologique de la Cote-d’Ivoire (J. Decelle, 1961-1964). XXV. Diptera Asilidae. 15 pp. 

 Oldroyd H., 1968: Diptera Tabanidae. Pp. 373-378. Contributions a la connaissance de la faune entomologique de la Cote-d’Ivoire. J. Decelle, 1961-1964. Premiere partie. XXIV. 6 pp. Ann. Mus. Roy. Afr. Centr. Zool. 165: 373-378.