Brown lacewings (Hemerobiidae) are a family of insects belonging to the order Neuroptera. Hemerobiidae is a family of Neuropteran insects, commonly known as brown lacewings, comprising approximately 500 species across 28 genera. While some genera, such as Hemerobius, Micromus, Sympherobius, and Wesmaelius, are widely distributed, most are confined to a specific biogeographical region. Like chrysopids, hemerobiids are predators, feeding primarily on aphids both as larvae and adults (Aspöcket al., 2016). The genus Wesmaelius is widely distributed in Asia, Africa, Europe, and North America and has a diversity of species in the temperate regions of North America and Eurasia. Presently, about sixty-five species are recorded in the world (Aspöck et al., 1980; Makarkin, 1986, 1996; Klimaszewski, Kevan, 1987), with ten specie srecorded from Ukraine (Zakharenko, 1997, Serediuk, 2016). Twenty-nine specimens of Wesmaelius, belonging to three species, are stored in the main collection of the museum. All of them were collected and identified by Józef Dziędzielewicz at the end of the 19th and beginning of the 20th century. Wesmaelius (Wesmaelius) concinnus (Stephens, 1836) is a transpalaearctic species. It has been recorded in Ukraine in the central part of the mixed forest zone and in the Carpathians (Ivano-Frankivska and Zakarpatska oblasts). The SMNH collection contains 11 specimens of W. concinnus. Six of them were collected in Lviv in June 1903 in Briukhovychi – four specimens, and one specimen without a specified collection date. One specimen was collected on June 17th in the village of Velykyi Liubin and another on June 19th in Kryvchytsi, in Lvivska oblast. Additionally, there are three W. concinnus specimens collected on June 15th and 17th (year not specified) in Lubaczów, Poland. Wesmaelius (Kimminsia) nervosus (Fabricius, 1793) is a European-West Siberian species. In Ukraine, it is only found in the Carpathian Mountains. Six specimens of W. nervosus are stored in the collection of the SMNH. Four of them were collected in Lviv in May, the year of which is unknown. The fifth specimen was collected on August 3, 1908 near the town of Vorokhta in Ivano-Frankivska oblast. There is no information about the place and date of collection for one more specimen. Wesmaelius (Wesmaelius) quadrifasciatus (Reuter, 1894) is a transpalaearctic species. In Ukraine, it is only known from the Carpathians (Lvivska, Ivano-Frankivska, and Zakarpatska oblasts). The SMNH collection contains 13 specimens of W. quadrifasciatus. Four of them were collected in Lviv (Vulka, Zubra, Stryiskyi park) in May and June 1904-1905 and 1910. Another specimen was collected in Rava-Ruska, Lvivska oblast July 18th, and the year of discovery is unknown. Six specimens were collected in the Ivano-Frankivska oblast. In 1908, two specimens were collected on June 17th in the vicinity of Vorokhta, and another specimen was collected on June 20th of the same year on Mount Rebrovachka. In 1905, one specimen was collected on June 29th in the vicinity of the village Tatariv, and another specimen was collected on July 2nd of the same year in the vicinity of the village of Yablunytsia. Also, there is one specimen in the collection collected in the slope of Mount Khomiak near the village Tatariv on June 12th, 1909. In addition, two specimens of W. quadrifasciatus are from Poland – one collected on July 7th, 1905 in Jasień, and another collected on July 27th, 1909 in the vicinity of Zawoja (Babia Góra Mount).