1. Despite a growing interest in forest canopy biology, very few studies have examined the vertical distribution of forest bees. In this study, bees were sampled using 12 pairs of flight-intercept traps suspended in the canopy ( ‡15 m) and near the ground (0.5 m) in a bottomland hardwood forest in the southeastern United States.2. In total, 6653 bees from 5 families and 71 species were captured. Augochlora pura (Say) (Halictidae), accounted for over 91% of all bees collected and was over 40 times more abundant on average in the canopy than near the ground.3. Even after removing A. pura from the dataset, bee abundance, richness and Shannon's diversity were considerably higher in the canopy than near the ground.4. According to both non-metric multidimensional scaling and analysis of similarities, the bee community in the canopy was distinct from that near the ground. Based on indicator species analysis, A. pura, Lasioglossum imitatum (Smith), Lasioglossum versatum sensu Mitch., and Lasioglossum zephyrum (Smith) were significantly associated with the canopy whereas Andrena personata Robertson and Lasioglossum macoupinense (Robertson) were significantly associated with the ground. 5. Augochlora pura was consistently more abundant in the canopy than near the ground throughout the season, but was more so in mid-to-late summer (i.e., June-September), a period coinciding with low floral resource availability. As a group, the remaining bee community exhibited a similar pattern.6. We suspect that bees frequent the canopy, particularly during times of low nectar and pollen availability, to acquire non-floral resources such as honeydew and sap.

The Empria longicornis species group (Hymenoptera, Tenthredinidae) is revised. Empria japonica Heidemaa & Prous, sp. nov. is described from Japan. The lectotypes of Empria gussakovskii Dovnar-Zapolskij, 1929, E. konowi Dovnar-Zapolskij, 1929, Poecilosoma longicornis Thomson, 1871, P. mongolica Konow, 1895, and P. tridens Konow, 1896 are designated. Empria konowi Dovnar-Zapolskij, 1929 (syn. nov.) and E. gussakovskii Dovnar-Zapolskij, 1929 (syn. nov.) are synonymized with E. tridens (Konow, 1896), and Empria waldstaetterense Liston, 1980 (syn. nov.) with E. alector Benson, 1938. Empria alpina Benson, 1938 and E. minuta Lindqvist, 1968, earlier misidentified as E. gussakovskii, are treated as valid species. Nine species are confirmed to belong in the longicornis-group: E. alector, E. alpina, E. basalis, E. japonica, E. loktini, E. longicornis, E. minuta, E. mongolica, and E. tridens. Distributional data of the species and a key to the imagines are provided. Ex ovo rearings of the four most common and often misidentified species in the group (E. alector, E. basalis, E. longicornis, and E. tridens) were carried out to verify their host plants and male conspecifics. External morphology, morphometrics (geometric and traditional), and DNA sequences (mitochondrial COI and nuclear ITS1 and ITS2) are used to delimit species within the group and to assess their phylogenetic relationships. Mitochondrial DNA sequences analyzed are mostly regarded as unsuitable for species circumscription, DNA barcoding and for reconstructing species phylogeny within the group. In this regard, analyses of the ITS sequences yielded more concordant results.

A critical and annotated review of published records of the Chrysididae of the Nordic and Baltic countries and the Russian part of Fennoscandia is presented with some taxonomic and faunistic notes. A total of 73 species are listed from the region. Additionally, 17 species are deleted. Three species are recorded for the first time from Denmark, six species from Estonia, one from Finland, eleven from Latvia, four from Norway, one from Sweden and 15 from Russian Fennoscandia. Elampus foveatus and Chrysis pulcherrima are reported for the first time from the Nordic and Baltic countries. Lectotypes are designated for Hedychrum cupreum Dahlbom, 1845, Chrysis zetterstedti Dahlbom, 1845, Chrysis succincta var. chrysoprasina Trautmann, 1927, Chrysis succincta var. virideocincta Trautmann, 1927 and Chrysis succincta var. nordstromi Trautmann, 1927. Information and images of the holotypes of Hedychrum metallicum Dahlbom, 1854, Chrysis var. westerlundi Trautmann, 1927 are given. Chrysis integra Dahlbom, 1829 is found to be a new synonym of Hedychridium ardens (Coquebert, 1801) and Chrysis scintillans Valkeila, 1971 a new synonym of Chrysis solida Haupt, 1957. Chrysis terminata Dahlbom, 1854 is reported for the first time as the valid name for C. ignita Form A sensu Linsenmaier, 1959.

The following eleven Empria species are reported from Japan: Empria candidata (Fallén, 1808), Empria japonica Heidemaa & Prous, 2011, Empria liturata (Gmelin, 1790), Empria loktini Ermolenko, 1971, Empria plana (Jakowlew, 1891), Empria quadrimaculata Takeuchi, 1952, Empria rubicola Ermolenko, 1971, Empria tridens (Konow, 1896), Empria tridentis Lee & Ryu, 1996, Empria honshuana Prous & Heidemaa, sp. n., and Empria takeuchii Prous & Heidemaa, sp. n. The lectotypes of Poecilosoma pallipes Matsumura, 1912, Empria itelmena Malaise, 1931, Tenthredo candidata Fallén, 1808, and Tenthredo (Poecilostoma) hybrida Erichson, 1851 are designated. Empria itelmena Malaise, 1931, syn. n. is synonymized with Empria plana (Jakowlew, 1891). Poecilosoma pallipes Matsumura, 1912, previously assigned to Empria, is transferred to Monsoma, creating Monsoma pallipes (Matsumura, 1912), comb. n. Results of phylogenetic analyses using mitochondrial (COI) and nuclear (ITS1 and ITS2) sequences are also provided.

The Chrysididae are a group of cleptoparasitic and parasitoid aculeate wasps with a large number of rare and endangered species. The taxonomy of this group has long been confusing due to the similarity of species and extensive intraspecific variation. We present for the first time a comprehensive dichotomous key for all 74 species found in the Nordic and Baltic countries. In addition to diagnostic characters, information on the distribution and biology of each species is also presented. A new species, Chrysis borealis Paukkunen, Ødegaard & Soon, sp. n. is described on the basis of specimens collected from Fennoscandia. Chrysis gracillima Förster, 1853 is recorded as new to the Nordic and Baltic countries.