Eucerini

Abstract: Fifty-four genera of the bee family Apidae comprising almost all tribes were analysed based on 77 traditional and one new character of the mature larvae. Nine, especially cleptoparasitic species, were newly added. Analyses were per- formed by maximum parsimony and Bayesian inference. Trees inferred from the analysis of the complete dataset were rooted by taxa from the families Melittidae and Megachilidae. Unrooted trees inferred from the analysis of the partial dataset (excluding outgroup taxa) are also presented to preclude possible negative effects of the outgroup on the topology of the ingroup. Only the subfamily Nomadinae was statistically well supported. The monophyly of the subfamilies Xylocopinae and Apinae was not topologically recovered. The monophyly of the tribe Tetrapediini was supported, and this tribe was found to be related to xylocopine taxa. At the very least, larval morphology suggests that Tetrapedia is not a member of the subfamily Apinae. Our analyses support the monophyly of the Eucerine line (Emphorini, Eucerini, Exomalopsini, Tapinotaspidini) and of the Apine line (Anthophorini, Apini, Bombini, Centridini, Euglossini, Meliponini). All analyses support the monophyly of totally cleptoparasitic tribes of the subfamily Apinae. We named this group the Melectine line (Ericrocidini, Isepeolini, Melectini, Osirini, Protepeolini, Rhathymini). In previous studies all these cleptoparasitic tribes were considered independent evolutionary lineages. Our results suggest that their similarities with hosts in morphology and pattern are probably the result of convergence and host-parasite co-evolution than phylogenetic affinity. According to the present analysis, the cleptoparasitism has evolved independently only six times within the family Apidae.

Abstract: Cucurbita flowers are monoecious, the male and female flowers requiring a pollinator to transfer pollen. Bees were systematically collected as they visited flowers of three cultivated Cucurbita species grown at seven separate localities of Santa Catarina state in southern Brazil. Additionally, pantraps were used to estimate the general bee diversity at three of these locations. In total, 3.270 bees were sampled representing 50 species, with 3.153 bees (24 species) counted during censuses on the flowers and 117 individuals of 30 species in the pantraps. The most abundant bee species was Apis mellifera (32%) followed by the squash specialist, Peponapis fervens (25%). This latter species was present at five of the seven study localities. It was the most abundant bee at Cucurbita in three of these places. Nests of P. fervens were found in two localities. Each vertical nest was excavated in clay soil and occupied by a single female. Pollen analyses of the larval provision revealed that the females collect pollen only on squash flowers (100% Cucurbita pollen grains) confirming its specialization. The presence of this bee species in the study area seems to be related to the good environmental condition and stewardship by the farmers, especially their careful use of insecticides.

Abstract: Data are presented on the nesting and phenology of Canephorula apiformis Friese (Apidae: Eucerini), a monotypic genus of bees endemic to the arid and semi-arid regions of the Argentinian northwest. Aggregations of nests are found in the ground where the surface is horizontal and frequently exposed to the sun. The brood cells, 5–6 cells per nest, are at an approximate depth of 20 cm. Floral hosts include Prosopis strombulifera (Fabaceae), Atamisquea emarginata (Capparidaceae), Larrea divaricata (Zygophyllaceae), and Tessaria absinthioides (Asteraceae) and are visited mainly between 10:00 and 14:00 hr. Adults and immature stages of Melectoides bellus (Jorgensen) (Apidae: Isepeolini) were found in the nests, the first association for this cleptoparasitic tribe with any host other than the genus Colletes. Canephorula apiformis may have two generations per year while the voltinism of its cleptoparasite is uncertain. The mature larvae of both host and cleptoparasite are described for the first time and...