While the presence of secondary compounds in floral nectar has received considerable attention, much less is known about the ecological significance and evolutionary origin of secondary ‘toxic’ compounds in pollen. It is unclear whether the presence of these compounds in pollen is non‐adaptive and due to physiological ‘spillover’ from other floral tissues, or whether these compounds serve an adaptive function related to plant–pollinator interactions, such as protection of pollen against pollen thieves. Combining an experimental approach with phylogenetic comparative methods, and using western Palaearctic Boraginaceae as a model system, we investigate how pollen secondary metabolites influence, and are influenced by, relationships with bees, the main functional group of pollen‐foraging pollinators. We found a significant relationship between the levels of secondary compounds in the corollas and those in the pollen in the investigated species of Boraginaceae, suggesting that baseline levels of pollen secondary compounds may partly be due to spillover from floral tissues. At realistic levels, pollen secondary compounds showed significant detrimental effects on bee pre‐imaginal development, in agreement with previous egg‐transfer experiments showing that in some cases Boraginaceae pollen did not support pre‐imaginal development in bees not specialized on these plants. We also show that phylogenetically independent Boraginaceae taxa rewarding pollinators with pollen in addition to nectar exhibit significantly lower levels of toxic compounds in the pollen than taxa where the main reward is postulated to be nectar. Lastly, in contrast to our predictions, there was no positive association between toxin levels in the pollen of a given plant taxon and the number of bee species specialized on this taxon. We integrate all these findings and formulate an evolutionary scenario to account for the presence of toxic compounds in the pollen of Boraginaceae. We suggest that baseline levels of toxic compounds may be found in pollen due to spillover from other floral tissues and not primarily because of bee–flower interactions. Since pollen toxins can have detrimental effects on bees, we propose that selection acts to lower pollen toxin levels in plants where pollen, in addition to nectar, serves as a reward to bees. A free Plain Language Summary can be found within the Supporting Information of this article.

Using a combination of DNA barcodes and morphology, we examine species boundaries in bees of the genus Andrena subgenus Taeniandrena in Europe. First, we solve the long controversy surrounding the status of Andrena ovatula (Kirby, 1802) and A. albofasciata Thomson, 1870, proposed to represent distinct species nearly 100 years ago, but mostly treated as conspecific in recent studies. Our results unambiguously support the presence of two taxa that are often found in sympatry: the first taxon, referred to as A. ovatula, is present in Northern Europe but also in Southern Europe along the Mediterranean coast; the second taxon is referred to as A. afzeliella (Kirby, 1802), stat. rev., with A. albofasciata considered to be a junior synonym (syn. nov.), and is widely distributed in Europe. Second, we show that another widely distributed species has hitherto been overlooked in Europe: A. ovata Schenck, 1853, stat. rev. Third, we demonstrate that two taxa currently treated as subspecies should be given specific rank due to significant morphological and genetic differences: A. croceiventris Morawitz, 1871, stat. rev., so far treated as a subspecies of A. similis Smith, 1849, and A. vocifera Warncke, 1975, stat. nov., so far treated as a subspecies of A. gelriae van der Vecht, 1927. Both A. croceiventris and A. vocifera have particularly restricted ranges in Europe, being known only from central to southern Italy and Sicily, and continental France, respectively. Fourth, we describe a new species from Sardinia and Corsica, A. antonellaesp. nov. Lastly, the following new synonymies are proposed: A. similis, A. ocreata cyprisina Warncke, 1975 and A. similis caraimica Osytshnjuk, 1994 are placed in synonymy with A. russula Lepeletier, 1841 (syn. nov.); A. fuscata (Kirby, 1802), A. canescens Schenck, 1853 and A. pseudovatula Alfken, 1926 are placed in synonymy with A. afzeliella (syn. nov.). Lectotypes are designated for A. afzeliella, A. fuscata (Kirby, 1802), A. ovata and A. wilkella (Kirby, 1802). Our results suggest a particularly fast diversification in this group of bees, leading to the presence of numerous species exhibiting particularly restricted geographic ranges. We discuss the implications for conservation of this astonishing cryptic diversity in European bees.

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herein we present information on the nesting behavior of Ochreriades fasciatus (Friese) found occupying beetle galleries in dead trunks and branches of certain trees and shrubs in israel. We also describe the pre-and postdefecating larvae thereby making known the mature larva for this uncommon Old World genus. Females of O. fasciatus build linear nests in existing burrows in dead wood; depending on the length of the burrow, 1-5 cells are placed in one nest. The cell partitions are made of hardened mud, while the nest plug consists of pebbles fixed together with mud. Ochreriades fasciatus is oligolectic on Lamiaceae and probably strongly associated with the two related genera Ballota and Moluccella. it is hoped that information concerning its nesting biology, host-plant relationships, as well as larval development and anatomy will eventually prove valuable in determining the phylogenetic position of this genus relative to other megachiline bees.1 division of invertebrate zoology, American Museum of Natural history. 2 steinhardt Museum of Natural history and National research center, Faculty of Life sciences, tel Aviv university, israel. 3 institute of Biology, university of Neuchatel, switzerland. 4 department of entomology, cornell university.

The leafcutting bees of the leachella group of Megachile Latreille subgenus Eutricharaea Thomson are revised for the Western Palaearctic region using a combination of morphology and phylogenetic analyses of three genes (COI, LW-Rhodopsin, CAD). Although only seven species are recognized, much effort was needed to link delimitated taxonomic units to taxon names because of the difficulties in identifying type specimens. Numerous types were in a poor state of conservation, preventing straight-forward identification using morphology. This was in some cases aggravated by the fact that they often belonged to a sex that could not easily be identified; one type was a gynandromorph specimen whose identification is even more challenging. In several cases, the type locality was vague or unclear; in three cases, the type specimens originated from introduced populations for which the source of the introduction needed to be determined using DNA barcoding. In two cases, the type specimens consisted of several body parts not originating from a single individual but from two heterospecific specimens. We argue that this tedious nomenclatural work would have been greatly facilitated if a reference library of type specimens had been available. Our revision leads to the following taxonomic changes. Megachile argentata (Fabricius, 1793), described from northern Africa and with a convoluted taxonomic history, is demonstrated, based on morphometric analyses of its lectotype, to be conspecific with the species hitherto known as M. pilidens Alfken, 1924. After discussing and excluding several alternative options that would minimize nomenclatural changes, we place M. pilidens in synonymy with M. argentata (syn. nov.). Two new subspecies are described for morphologically slightly divergent insular populations, M. leachella cretica Praz, ssp. nov. from Crete, and M. leachella densipunctata Praz, ssp. nov. from Cyprus. In addition, M. albipila Pérez, 1895 is treated as a subspecies of M. leachella Curtis, 1828 (stat. nov.). The following new synonymies are proposed: M. compacta Pérez, 1895 (not M. compacta Smith, 1879) and the replacement name M. crassula Pérez, 1896, M. argyrea Cockerell, 1931 and Perezia maura Ferton, 1914, are placed in synonymy with M. argentata (syn. nov.). M. beaumonti Benoist, 1951, is newly treated as a valid species (stat. rev.). M. schmiedeknechti Costa, 1884 is treated as a subspecies of M. argentata (stat. nov.), and M. xanthopyga Pérez, 1895 is placed in synonymy with M. argentata schmiedeknechti (syn. nov.). M. bioculata Pérez, 1902, M. discriminata Rebmann, 1968 and M. ichnusae Rebmann, 1968 are placed in synonymy with M. leachella (syn. nov.). M. variscopa Pérez, 1895, M. timberlakei Cockerell, 1920, M. atratula Rebmann, 1968, M. striatella Rebmann, 1968 and M. sudai Ikudome, 1999 are placed in synonymy with M. pusilla Pérez, 1894. Lectotypes are designated for M. albipila, M. bioculata, M. compacta Pérez, M. pusilla, M. variscopa and M. xanthopyga.