Meaningful ecological studies on insect communities require sampling protocols that take into consideration temporal fluctuations in abundance and species composition. Bees with their specific requirements for nutrition and nesting are good indicators of landscape structure and overall biodiversity, provided the ecological and seasonal patterns they show are taken into consideration. The present two year study traced the ecological and seasonal patterns on 2 km2 of a southern slope in the Swiss Alps, ranging from 1150 to 1550 m above sea level. The study area consisted mainly of grassland under different regimes, mostly hay meadows and pastures. By direct netting at five monthly intervals in each year a total of 247 bee species were recorded. This comprehensive sampling scheme identified one of the most diverse bee faunas in Central and Northern Europe, consisting of a statistically estimated 280 species. Most species were rare with 14.6% represented by a single individual. Ecological analysis of the bee community showed that the primitively eusocial species were over represented among the abundant species and the parasitic species among the rarest.Both abundance and species richness were subject to marked seasonal variations. A substantial turnover in species composition as well as changes in ecological patterns were observed. More than 25% of all species were recorded in only one of the two years, in particular many of the parasitic species. Singletons accounted for a higher proportion when individual years rather than the pooled data were analysed. All these findings underline the importance of season-long sampling and sampling over more than one year if bees are to be used as indicators in ecological and studies on bee communities.

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Ecological and seasonal patterns in the diversity of a species-rich bee assemblage (Hymenoptera: Apoidea: Apiformes)

Substantial industrial development, agricultural intensification, and an increasing human population have led to the demise of many seminatural habitats, such as wet meadows, in many countries of Europe. This process can cause the extinction and decline of associated insect species. The present paper is the first study analyzing wild bee diversity and abundance patterns in wet meadows. We surveyed bees using pan traps, transect walks, and nest traps in four Molinietum (Poaceae) meadows near Krakow, Poland. During one season, we identified a relatively high γ-diversity of wild bees, consisting of 105 species (13 from the Polish Red List) belonging to 22 genera, which represent almost one-fourth of the Polish bees. The wild bee fauna between sites was not variable, which was indicated by low s-diversity. We found that nesting preference of bees did not differ between the study area and xerothermic meadows, which suggests that differentiation in bee fauna of wet and dry grasslands is mostly due to food specialization rather than nesting preference. Abundance analysis of the bee community showed that the least abundant species were disproportionately comprised of oligolectic species, indicating that species closely associated to plants of wet meadows are especially threatened. Moreover, using occurrence data we found that 34% of the species belonging to the families Halictidae, Melittidae, and the tribe Nomadini found in wet meadows are considered rare in Poland. Our results highlight an urgent need to perform further investigations and develop specific protection plans for bees not only in Krakow’s Molinietum meadows, but also in wetlands throughout Europe.

https://bioone.org/journals/Wetlands/volume-28/issue-4/08-83.1/Diversity-Of-Wild-Bees-In-Wet-Meadows--Implications-For/10.1672/08-83.1.pdf

Diversity Of Wild Bees In Wet Meadows: Implications For Conservation

Bees comprise a monophyletic group of seven families with more than 16000 described species worldwide. Convincing new phylogenetic hypotheses suggest that one of the smallest families, the Melittidae, could be the basal group of the bee clade. Among the 14 melittid genera, the genus Melitta Kirby 1802, is the most widespread and one of the most diverse. Most revisionary studies of Melitta were confined to limited geographical areas. An overview of the literature and the examination of 7817 specimens from various collections, including type material, have enabled the first monographic revision of the genus Melitta. This revision includes a cladistic analysis, comprehensive catalogue and identification key. We provide diagnoses, global distributions, phenology and host plants for the 43 known species (including 2 new ones). Lectotypes are designated for M. albofasciata Friese 1900, M. caroli Cameron 1909, M. schultzei Friese 1909 and M. sibirica (Morawitz 1888). We described M. rasmonti n. sp., M. ...

https://www.tandfonline.com/doi/pdf/10.1080/00379271.2007.10697535

Monographic revision of the bee genus Melitta Kirby 1802 (Hymenoptera: Apoidea: Melittidae)

One of the most noticeable features of the urban climate is the air temperature increase in the city compared to the surrounding area (“urban heat island”). This study focused on the influence of urban climate on the occurrence of thermophilic and xerothermic bee species from southern Europe. The southern species were relatively common among the bee assemblages observed within the area of Poznan, Poland. In Central Europe, these species are observed only in isolated xerothermic localities and, as shown by the present study, in the urban areas. Cities enable some of the Southern European species of bees to move north. During this study, species that are rare in Poland were also observed. In that respect, the study also draws attention to the importance of urban areas in preserving biodiversity.

https://link.springer.com/content/pdf/10.1007%2Fs13592-013-0232-7.pdf

Are urban areas suitable for thermophilic and xerothermic bee species (Hymenoptera: Apoidea: Apiformes)?

The study focused on aculeate Hymenoptera recorded at 114 study plots on seven brown coal spoil heaps (reclaimed and under spontaneous succession) situated in the North Bohemian Brown Coal Basin, Czech Republic. In total, 2706 individuals of 212 species from 13 families were collected using Moericke traps. Of this number, 46 rare species (2 regionally extinct, 7 critically endangered, 14 endangered, and 23 vulnerable), 5 species protected by law, and 3 other rare species were recorded. Species typical of sand banks and open landscape were most numerous. The communities were dominated by Lasioglossum species, Diodontus minutus and Bembecinus tridens on unreclaimed sites, and Apis mellifera, Lasioglossum pauxillum, and Osmia rufohirta on reclaimed sites. Unreclaimed sites hosted twice as many rare species at four times greater abundances. Rare species occurred there more frequently than at reclaimed sites. Species known as regionally extinct, Evagetes littoralis and Nomada minuscula, were found only on unreclaimed sites. Redundancy analysis showed that especially threatened species are connected with sandy sites small in area and with sparse vegetation cover. The number of rare species slowly increased with age, but young sites, too, could be very rich. It is recommended to combine succession and reclamation approaches to create suitable nesting habitats, refuges, and food resources. It is essential to maintain a fine mosaic of habitats in various (above all young) successional stages.

Combination of reclaimed and unreclaimed sites is the best practice for protection of aculeate Hymenoptera species on brown coal spoil heaps

. In xerothermic swards and thickets at 17 research sites in the lower Vistula valley (N Poland), 253 species of bees (Apiformes) were recorded. Southern and southeastern species (Ponto-Mediterranean, Pontic and Mediterranean) accounted for 20% of all recorded species. Substantial differences in species composition, diversity, and dominance structure were found between research sites and also between small plots (about 3 ha each) within one reserve. A discussion of the origin of the fauna of the study area suggests that the migratory route along the Vistula river from the Podolye refuge (W Ukraine) probably played a major role, beside two other routes: along the Torun-Eberswalde Proglacial Valley from Germany and across the Moravian Gate from the south. A northward decrease in diversity of southern and southeastern species was confirmed.

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J. Banaszak

Papers

Bees of xerothermic swards in the lower Vistula valley: diversity and zoogeographic analyses (Hymenoptera:Apoidea:Apiformes)

Bees [Hymenoptera; Apoidea] of the Bory Tucholskie National Park [NW Poland]