Bee phenology is predicted by climatic variation and functional traits.

Climate change is shifting the environmental cues that determine the phenology of interacting species. Plant-pollinator systems may be susceptible to temporal mismatch if bees and flowering plants differ in their phenological responses to warming temperatures. While the cues that trigger flowering are well-understood, little is known about what determines bee phenology. Using generalised additive models, we analyzed time-series data representing 67 bee species collected over 9 years in the Colorado Rocky Mountains to perform the first community-wide quantification of the drivers of bee phenology. Bee emergence was sensitive to climatic variation, advancing with earlier snowmelt timing, whereas later phenophases were best explained by functional traits including overwintering stage and nest location. Comparison of these findings to a long-term flower study showed that bee phenology is less sensitive than flower phenology to climatic variation, indicating potential for reduced synchrony of flowers and pollinators under climate change.

A revision of the subgenus Osmia (Diceratosmia), with descriptions of four new species (Hymenoptera, Megachilidae).

The eleven species of the North American subgenus Osmia (Diceratomsia) are revised, four of which are new: Osmia (Diceratosmia) exquisita, n. sp., from Honduras; Osmia (Diceratomia) gonzalezi, n. sp., and Osmia (Diceratomia) spinulifera, n. sp., from Mexico; and Osmia (Diceratomsia) lacunosa, n. sp., from the Bahamas. Diagnoses for the remaining seven species and a key to the males and females of all species are provided. We newly designate a neotype for Osmia botitena Cockerell, junior synonym of Osmia subfasciata Cresson, and remove from synonymy Osmia marilaunidii Cockerell, new status. In addition, we review the known nesting biology, floral hosts, and geographic range of each species.

The bees of Michigan (Hymenoptera: Apoidea: Anthophila), with notes on distribution, taxonomy, pollination, and natural history.

The state of Michigan occupies an area between the Great Plains and the northeastern United States, bordering four Great Lakes, with diverse biogeographical regions. Michigan also has the second most diverse agriculture in the country, with many crops that depend on bees for pollination. This unique combination provides a wide range of opportunities for bees to persist, yet there is no current published checklist of these important insects. This study was conducted to provide the first annotated checklist of the bee (Apoidea: Anthophila) fauna of Michigan, summarizing aspects of their taxonomy and behavior and to provide provisional conservation assessment. The list was compiled from a critical review of published literature, museum specimens, and database records, supplemented by new collections. In total, 465 species are included in the checklist, including 38 new records, however evidence for 13 species is poor, several more species require taxonomic revision, and the presence of additional species is expected. The exotic megachilid species Megachile apicalis Spinola, M. pusilla Pérez (=concinna Smith, auct.) and Osmia taurus Smith are reported from Michigan for the first time. New state records of native species include Anthidium tenuiflorae Cockerell and Nomada alpha alpha Cockerell, both previously undocumented from eastern North America, and Nomada sphaerogaster Cockerell, which has rarely been recognized. The taxonomy of some bee species is clarified by the formal publication of 11 new synonymies (some previously reported online or in manuscripts). The following list cites junior synonyms first followed by the valid name: Andrena chippewaensis Mitchell 1960 = A. (Simandrena) wheeleri Graenicher 1904; Osmia hendersoni Cockerell 1907 = O. (Melanosmia) tarsata Provancher 1888; Osmia michiganensis Mitchell 1962 = O. (M.) subarctica Cockerell 1912 (new status, removed from synonymy with O. (M.) tersula Cockerell 1912); Sphecodes persimilis Lovell and Cockerell 1907 = S. davisii Robertson 1897; Sphecodes knetschi Cockerell 1898 = S. dichrous Smith 1853; Sphecodes carolinus Mitchell 1956 = S. coronus Mitchell 1956; Sphecodes stygius Robertson 1893 = S. mandibularis Cresson 1872; Sphecodes prostygius Mitchell 1960 = S. fattigi Mitchell 1956; Stelis vernalis Mitchell 1962 = S. coarctatus Crawford 1916; and Stelis michiganensis Mitchell 1962 = S. foederalis Smith 1854. Poorly known Andrena (Cnemidandrena) are discussed, including A. parnassiae Cockerell, a new state record, A. robervalensis Mitchell, and the extralimital A. runcinatae Cockerell. Of these, only A. robervalensis was considered in the subgeneric revision, but we recognize all three as valid species pending further study. Nomada binotata (Robertson 1903) and N. quadrimaculata (Robertson 1903) are removed from synonymy with N. ovata (Robertson 1903), based on examination of the lectotypes. A new species, Triepeolus eliseae Rightmyer, the eastern representative of the verbesinae species group, is described. A putative undescribed species, Osmia aff. trevoris, is documented, but requires additional study for its status to be fully resolved. A rich bee fauna is documented that includes geographically-restricted species, rare and regionally-declining species, and economically-important species, providing information for ongoing conservation planning and future analysis of trends in bee populations.

A new species of Triepeolus (Hymenoptera: Apidae), with comments on T. utahensis (Cockerell) and T. melanarius Rightmyer.

Triepeolus matildae Rightmyer, sp. nov., from Mexico (Baja California) and USA (California) is described and both genders are differentiated from the closely related species T. utahensis (Cockerell) using morphological characters. The synonymy of T. utahensis and T. heterurus was established in Rightmyer (2008); however, the younger name was used in that treatment, an error that is corrected herein. Males of both T. matildae and T. utahensis are additionally differentiated from T. melanarius Rightmyer, which is morphologically similar in that gender only. DNA barcoding evidence supporting the recognition of the new species is additionally presented.

Osmia species (Hymenoptera, Megachilidae) from the southeastern United States with modified facial hairs: taxonomy, host plants, and conservation status.

We describe females and males of Osmia (Melanosmia) calaminthaesp. n., an apparent floral specialist on Calamintha ashei (Lamiaceae), and provide observations on the behavior of female bees on flowers of this plant. We also provide diagnostic information for Osmia (Diceratosmia) conjunctoides Robertson, stat. n., and synonymize Osmia (Diceratosmia) subfasciata miamiensis Mitchell with Osmia conjunctoidessyn. n. Females of both Osmia calaminthae and Osmia conjunctoides are unique among North American Osmia for having short, erect, simple facial hairs, which are apparent adaptations for collecting pollen from nototribic flowers. Osmia calaminthae is currently only known from sandy scrub at four nearby sites in the southern Lake Wales Ridge in Highlands County, Florida, USA, while Osmia conjunctoides is known from limited but widespread sites in the southeastern USA. We discuss the conservation status of both species based on known or speculated floral associates and distributions.

A review of the non-metallic Osmia (Melanosmia) found in North America, with additional notes on palearctic Melanosmia (Hymenoptera, Megachilidae).

We review the six species of non-metallic Osmia (Melanosmia) found in North America, including the description of two new species found in Canada and the northern United States: Osmia (Melanosmia) aquilonariasp. n., and Osmia (Melanosmia) nearcticasp. n., respectively belonging to the inermis and xanthomelana species groups. We additionally provide keys to the non-metallic Melanosmia found in North America, and update keys to the palearctic Melanosmia based on study of the type specimens of Osmia disjuncta Tkalcu, Osmia ephippiata Smith, Osmia ishikawai Hirashima, and Osmia pamirensis Gussakovskij.