Nesting Behavior, Phenology, and Bionomics of the High Andean Leaf-Cutter Bee Megachile (Cressoniella) amparo.

Megachile amparo (González, Revista Colombiana De Entomología 32(1):93-96, 2006) is the only high Andean leaf-cutter bee reported in Colombia and is possibly endemic to the Colombian Andes. Although it is frequently observed, even in urban areas, its biology and ecology remain unknown. The present study aimed to describe detailed aspects of its bionomy. Trap-nests were installed on the Campus of the Nueva Granada University (Cajicá, Colombia) from June/2018 to March/2020. The trap-nests were wooden blocks (25 × 15 × 14 cm) with 30 cavities of Ø = 1 cm and different lengths (50 mm, 75 mm, and 100 mm) lined with waxed paper straws. During the observations, an increasing number of trap-nests were installed, increasing from 250 to 720 cavities. The trap-nests were monitored three times a week, recording both the date the start and end building by female. Most of the nest were maintained in the field to estimate the sex ratio, cell survival, and total development time under natural conditions. Thirty-two nests were removed at different times of the observation period to establish number of cells per nest, and cells built per female per day. We incubated 20 cells from different nests at 18 °C, 22 °C, 26 °C, and 32 °C to estimate the base temperature, thermal constant k (developmental time in degree days), and cell survival. Young cells of different positions were dissected and weighed to characterize food provision and brood cells. Computerized tomography-CT scans were performed in 30 brood cells to determine if diapause occurred during prepupal stage. Females nested 7- and 10-cm-long cavities and the number of cells per nest varied with cavity length. The brood cells had a length of 1.23 ± 0.12 cm and a diameter of 0.92 ± 0.05 cm. The female spends 1.17 ± 0.29 days to build a brood cell. Food provision varied according to the position of the brood cell in the nest. The adults of M. amparo present a marked seasonality being more active during dry months. Base temperature and thermal constant k were different for males and females. The sex ratio is female biased (1.9:1), and cell survival in the field was 89% with no cleptoparasites or predators recorded.

The bee subtribe Epanthidiina, a new taxon for the Neotropical clade of Anthidiini (Hymenoptera, Apidae, Megachilinae)

ABSTRACT Anthidiini comprise a large, diversified, and widely distributed tribe of megachiline bees. Recently, morphological and molecular analyses recovered five major monophyletic groups within the tribe. For this reason, we review the current classification of the tribe, giving status of subtribe to these lineages. A new subtribe, Epanthidiina (type genus: Epanthidium Moure), is proposed for a large group restricted to the Neotropical region. Morphological and molecular phylogenetic hypotheses support the taxonomic limits of the new subtribe. We also propose a new genus, Urbanthidium (type species: Anthodioctes gracilis Urban), in order to accommodate results from a previous study in which Anthodioctes Holmberg came out paraphyletic. Two species are transferred to the new genus: Urbanthidium gracile (Urban) comb. n., Urbanthidium psaenythioides (Holmberg) comb. n.

Revision of the rare anthidiine bee genus Rhynostelis Moure & Urban (Hymenoptera, Apidae)

Abstract The bee genus Rhynostelis Moure & Urban, a cleptoparasite taxon restricted to the Neotropical Region, was previously known from a single species. In the present work, the genus is revised, with three species recognized, of which two are described as new: Rhynostelis chrysogaster sp. nov. and Rhynostelis plesiognatha sp. nov. from Panamá and Brazil, respectively. Misidentification of the type species, Rhynostelis multiplicata (Smith, 1879), in previous works is pointed out and discussed. Diagnosis, illustrations and an identification key for the three recognized species are also provided.

First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile / Primeiras observações sobre a biologia da nidificação de Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) no vale de Azapa, norte do Chile

First remarks on the nesting biology of Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) in the Azapa valley, northern Chile. Some aspects about the nesting biology of the potter wasp Hypodynerus andeus (Packard, 1869) are reported for the first time. Observations were carried out at the Azapa valley, coastal desert of northern Chile. A total of sixty nests were collected and examined, each composed by 1-14 cells, most of them found attached to concrete lamp posts. The only preys recorded in the cells were Geometridae (Lepidoptera) caterpillars and the presence of the parasitoid Anthrax sp. (Diptera, Bombyliidae) was also recorded. A number of arthropods belonging to different groups, mainly spiders, were found occupying empty nests.

Primeiras observações sobre a biologia da nidificação de Hypodynerus andeus (Packard) (Hymenoptera, Vespidae, Eumeninae) no vale de Azapa, norte do Chile. Alguns aspectos da biologia da nidificação da vespa Hypodynerus andeus (Packard, 1869) são registrados pela primeira vez. As observações foram conduzidas no vale de Azapa, deserto litoral do norte do Chile. Sessenta ninhos foram coletados e examinados, cada um composto por 1-14 células. A maioria dos ninhos estava aderida a postes de concreto. As únicas presas registradas nas células foram larvas de Geometridae (Lepidoptera). Um parasitóide, Anthrax sp. (Diptera, Bombyliidae), foi também registrado. Vários artrópodes, principalmente aranhas, foram encontrados utilizando ninhos vazios.