Yasumatsu K., 1955: On the bee fauna of the Bonin Islands. 5 pp. 

 Yasumatsu K., 1955: Taxonomic notes on three wireworm parasites of the genus Pristocera from the far east (Hymenoptera: Bethyloidea). 17 pp. 

 Yasumatsu K., 1956: Two new species of Roproniidae (Hymenoptera). 6 pp. 

 Yasumatsu K., 1958: A new addition to the genera of the Sclerogibbide (Hymenoptera). 5 pp. 

 Yasumatsu K., 1958: A new species of the genus Ropronia from Saghalien (Hymenoptera, Roproniidae). 3 pp. 

 Yasumatsu K., 1960: Notes on two species of Japanese Bethyloidea (Hymenoptera). 6 pp. 

 Yasumatsu K., 1960: The identity of Paralipsis enervis (Nees) and P. eikoae (Yasumatsu) (Hym., Aphidiidae). 2 pp. 

 Yasumatsu K., 1962: A new species of Telenomus from the Ryukyus (Hym., Scelionidae). 2 pp. 

 Yasumatsu K., Hirashima Y., 1952: Nomada comparata Cockerell and its allied species, Nomada hananoi n. sp. from S. Manchuria (Hymenoptera, Apidae). 6 pp. 

 Yasumatsu K., Hirashima Y., 1953: Three new species of the genus Nomada from Japan and Korea (Hymenoptera, Apidae). 8 pp. 

 Yasumatsu K., Hirashima Y., 1964: Carpenter bees of Japan and the Ryukyus, with a note on Xylocopidae nest by J. C. Harrell (Hymenoptera, Apoidea). 11 pp. 

 Yasumatsu K., Hirashima Y., 1965: Bees (Excluding Halictidae) of the Ruykyu Islands taken in the 1963 and 1964 surveys (Hymenoptera, Apoidea). 13 pp. 

 Yasumatsu K., Hirashima Y., 1965: Two new species of Megachile from Taiwan (Hymenoptera, Apoidea). 12 pp. 

 Yasumatsu K., Ishikawa R., 1955: Four new or little known Pompilidae from Japan (Hymenoptera). 4 pp. 

 Yefremova Z. A., 1994: A new species of the genus Euplectrus Westwood from Vietnam (Hymenoptera, Eulophidae). 2 pp. Russian Entomol. J. 3(1-2): 149-150.

 Yefremova Z. A., 1997: Trophic links of chalcids of the subfamily Eulophinae (Hymenoptera, Eulophidae) and their evolution. 12 pp. (in Russian). Entomologitsheskoe obozrenie 76(3): 535-546.

 Yefremova Z. A., Kriskovich M. V., 1996: A new species of Closterocerus Westwood, 1883 from Middle Asia (Hymenoptera, Eulophidae, Entedontinae). 4 pp. Entomofauna 17/28: 425-428.

 Yefremova Z. A., Shroll O. Yu., 1996: The male of Sympiesis albiventris Storozheva, 1981 (Hymenoptera, Eulophidae) from Turkmenistan. 2 pp. Russian Entomol. J. 5(1-4): 109-110.

 Yefremova Z. A., Vidal S., 1997: A new species of Hyssopus Girault, 1916 from Germany (Hymenoptera, Chalcidoidea: Eulophidae). 4 pp. [M23] Entomofauna 18/24: 401-404.

 Yefremova Z., Ebrahimi E., Yegorenkova E., 2007: The subfamilies Eulophinae, Entedoninae and Tetrastichinae in Iran, with description of new species (Hymenoptera: Eulophidae). 36 pp. Entomofauna 28/25: 321-356.

 Yegorenkova E. N., Lengesova N. A., Yefremova Z. A., 2010: Some biological data of Fenusa ulmi Sundevall, 1847 (Hymenoptera: Tenthredinidae) in Ulyanovsk region (Russia). 4 pp. Caucasian Entomological Bulletin 6(2): 199-202.

 Yen-ju W., Tai-lu C., Ting-shi L., Jyuhn-hua H., 1979: Descriptions of six new species of Telenomus (Hymenoptera: Scelionidae). 1 pp. 

 Yildirim E., 2016: Overview of the distribution and biogeography of Sapygidae in Turkey (Hymenoptera: Aculeata). 8 pp. Entomofauna 37: 565-572.

 Ying-Tou Mao, 1949: The species of ichneumon-flies of the genus Cardiochiles occurring in America North of Mexico. 40 pp. 

 Yokoi T., Hirooka T., Terada T., Sugimoto S., Tamaru M., Satoh S., Kandori I., 2012: Strongly biased sex ratio in cuckoo wasp Chrysura hirsuta (Hymenoptera: Chrysididae), a parasitoid of the mason bee osmia orientalis. 3 pp. Entomological Science 15(2): 250 – 252.

 Yokota S., Yamawo A., Suzuki N., 2012: Foraging, nutrition storage, and phenotypic plasticity in the major worker subcaste of Pheidole noda Smith (Hymenoptera: Formicidae). 12 pp. Japanese Journal of Entomology (N. S.) 15(4): 252-263.

 Yokoyama J., 1996: The Occurrence of Eupristina (Parapristina) verticillata Waterston (Hymenoptera, Agaonidae) in the Bonin Islands. 2 pp. 

 Yoneda Y., 1978: A new species of the genus ascogaster Wesmael (Hymenoptera, Braconidae) from Japan. 6 pp. Kontyu, Tokyo 46(2): 291-296.

 Yoon E. Y., Nam Y., Ryoo M. I., 2005: Effects of the milling degree of rice and storage volume on the interaction between Plodia interpunctella (Lepidoptera: Pyralidae) and its parasitoid Bracon hebetor (Hymenoptera: Braconidae). 6 pp. Journal of Asia-Pacific Entomology 8(3): 273-278.

 Yoshida N., Hirashima Y., 1979: Systematic studies on proctotrupoid and chalcidoid parasites of gall midges injurious to Pinus and Cryptomeria in Japan and Korea (Hymenoptera). 21 pp. 

 Yoshida T., Konishi K., 2008: Taxonomic study of the genus Dichrogaster Dourmec (Hymenoptera: Ichneumonidae: Cryptinae) in Japan. 12 pp. Entomological Science 11(2): 247-258.

 Yoshida T., Konishi K., 2014: A new species of the genus Polyaulon from Taiwan (Hymenoptera: Ichneumonidae: Cryptinae). 3 pp. Japanese Journal of Systematic Entomology 20(1): 21-23.

 Yoshikawa K., 1955: A polistine colony usurped by a foreign queen ecological studies of Polistews wasps, II. 6 pp. 

 Yoshikawa K., Ohgushi R. I., Sakagami S. F., 1969: Preliminary report on entomology of the Osaka City University 5th Scientific Expedition to Southeast Asia 1966. With descriptions of two new genera of stenogasterina wasps by J. van derVecht. 47 pp. 

 Yoshimoto C. M., 1958: A new species of Odynerus from the Hawaiian Islands (Hymenoptera: Vespidae). 2 pp. 

 Yoshimoto C. M., 1958: Revision of the Hawaiian Pemphredoninae (Hymenoptera: Sphecidae). 22 pp. 

 Yoshimoto C. M., 1960: Revision of Hawaiian Crabroninae with synopsis of Hawaiian Sphecidae (Hym.). 37 pp. 

 Yoshimoto C. M., 1962: Insects of Micronesia. Hymenoptera: Eucoilinae (Cynipoidea). 21 pp. 

 Yoshimoto C. M., 1963: Synopsis of Polynesian Cynipoidea (Hymenoptera: Eucoilinae). 11 pp. 

 Yoshimoto C. M., 1969: A biological note on Megachile (Eumegachile) umbripennis Smith (Hymenoptera, Apoidea). 2 pp. 

 Yoshimoto C. M., 1970: A new Eulophid parasite (Hymenoptera: Chalcidoidea) from eggs of the nursery pine sawfly, Diprion frutetorum (Hymenoptera: Tenthredinoidea). 3 pp. 

 Yoshimoto C. M., 1970: A new species of Astichus (Hymenoptera: Eulophidae) associated with the birch bracket fungus Polyporus betulinus and woody fungus Ganoderma applanatum in Eastern Canada. 5 pp. 

 Yoshimoto C. M., 1970: A new species of Tetrastichus (Hymenoptera: Eulophidae) parasitizing pupae of Sesamia inferens (Lepidopera: Noctuidae). 3 pp. 

 Yoshimoto C. M., 1970: A new subfamily of Cynipoidea (Hymenoptera) from Nepal. 3 pp. 

 Yoshimoto C. M., 1971: A new genus of Euderinae from South America (Hymenoptera, Chalcidoidea: Eulophidae). 5 pp. 

 Yoshimoto C. M., 1971: A new species of the genus Zamischus and description of the male Z. braziliensis (Hymenoptera, Cynipidae: Eucoilinae). 4 pp. 

 Yoshimoto C. M., 1971: Revision of the genus Euderus of America North of Mexico (Hymenoptera: Eulophidae). 38 pp. 

 Yoshimoto C. M., 1973: A new nearctic Derostenus (Hymenoptera: Eulophide) parasitic on Nepticula (Lepidoptera: Nepticulidae) in North America. 5 pp. 

 Yoshimoto C. M., 1973: Review of North American Chrysocharis (Kratochviliana) (Eulophidae: Chalcidoidea) North of Mexico, especially species attacking birch casebearer (Lepidoptera: Coleophoridae) and birch leafminer (Hymenoptera: Tenthredinidae). 31 pp. 

 Yoshimoto C. M., 1973: Revision of the genus Chrysocharis Förster (subgenus Chrysocharis s. str.) (Eulophidae: Chalcidoidea) of America North of Mexico. 29 pp.