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Background The Monteverde region of Costa Rica is a hotspot of endemism and biodiversity. The region is, however, disturbed by human activities such as agriculture and urbanisation. This study provides a list of orchid bees (Hymenoptera: Euglossini) compiled from field surveys conducted during January-October 2019 in the premontane wet forest of San Luis, Monteverde, Costa Rica. We collected 36 species of Euglossine bees across four genera. We provide new geographic distribution and elevation data for eight species in two genera. Due to their critical role in the pollination of orchids and other plants, the distribution and abundance of Euglossine bees has relevance to plant biodiversity and conservation efforts. This is especially important in a region with a high diversity of difficult-to-study epiphytic orchids, such as in the Monteverde region. [ABSTRACT FROM AUTHOR]

1. Many terrestrial herbivores supplement their diets with minerals. Neotropical stingless bees (Apidae: Meliponini) supplement their floral diets by visiting diverse non‐floral resources such as rotting fruit and muddy water. 2. Some stingless bees also visit carrion; however, it is unknown whether bees visit carrion for minerals or for another resource. Here, we investigated the mineral preferences of stingless bees visiting carrion. 3. We deployed raw chicken baits at La Selva Biological Station in Costa Rica consisting of six treatments: baits soaked in sodium, calcium, potassium, magnesium, or deionised water, and unsoaked baits. We identified and counted bee and non‐bee visitors to baits over three days. 4. We observed five species from three genera of stingless bee on the baits. Sodium baits and unsoaked baits were visited more often than other baits. Our findings demonstrate that stingless bees do forage for minerals on carrion, but that preferences are mineral‐specific. 5. In addition, three species packed carrion into their corbiculae. We hypothesise that facultatively necrophagous stingless bees may be using carrion as an alternative source of protein or nest‐building materials. [ABSTRACT FROM AUTHOR]

Stingless bees use extrafloral resources such as resins for nest construction, defense systems and chemical communication. We conducted the first study of the resin-collecting process from Croton yucatanensis Lundell shrubs by three stingless bee species in the tropical deciduous forest of the Guanacaste Conservation Area, Costa Rica. We performed systematic observations on 10 C. yucatanensis shrubs for 10-min periods between 8:20 a.m. and 3:00 p.m. for three days, and for 90 min we focused on behavior and interaction among bees on three shrubs. Trigona corvina Cockerell was the most frequent visitor. These bees made cuts on shrub stems and leaves to collect resin and transport it in their corbiculae. Others visitor species were Trigona fulviventris Guérin and Plebeia frontalis Friese, which tried to approach the resin remains left by T. corvina. While monopolizing the resource, T. corvina behaved aggressively if approached by T. fulviventris. Towards the last hour of sampling, T. fulviventris visits increased notably, which may indicate a decrease in the dominance or aggressiveness of T. corvina at that time. This tendency seems to be the beginning of temporal resource partitioning behavior commonly observed in bee communities. We provide novel observations on the ways in which stingless bees collect resin and the interactions that occur among them. We also propose and discuss working hypotheses to explain the fact that all the individuals observed almost exclusively visited a single C. yucatanensis specimen. [ABSTRACT FROM AUTHOR]

The stingless bee Melipona beecheii is extensively distributed across Mexico and Central America and the only Melipona found in the Greater Antilles. The aim of this work was to establish possible continental affinities of M. beecheii from the Antilles. We compared populations from the main island (Cuba) with two clearly separated genetic lineages of M. beecheii on mainland, namely the Yucatán peninsula (Mexico) and Costa Rica. We used morphometrics, the degree of cephalic maculation, and microsatellite variation. Results indicate a greater morphological and genetic similarity between populations from Cuba and the Yucatán peninsula with respect to those of Costa Rica. Based on our findings, we conclude that the origin of M. beecheii from Cuba is more likely the Yucatán peninsula (Mexico). We found evidence that isolation has not been large enough to result in a new genetic lineage. [ABSTRACT FROM AUTHOR]

Metallic coloration is one of the signatures of orchid bees of the genus Euglossa, with some species showing variation associated with their geographic range. Euglossa (Alloglossura) gorgonensis Cheesman exhibits color variation, ranging from mainly green specimens in the southern extreme of its range (Pacific slope of Colombia), to noticeably reddish specimens in parts of the northern known limits of its range (Pacific slope of southern Costa Rica). Here we present the first description of females from Costa Rica belonging to the reddish extreme of the color variation. [ABSTRACT FROM AUTHOR]

The incorporation of natural, non-crop vegetation in and around farmlands is a common practice in many agroecosystems, and may provide benefits both for production and conservation of biological diversity. In coffee agroecosystems, non-crop vegetation is routinely incorporated in the form of shade trees or forest habitat in and around coffee plants. In order to assess the importance of adjacent forest habitat to Hymenoptera associated with coffee farms, we sampled Hymenoptera on twelve coffee farms in the Tarrazú region in the central highlands of Costa Rica. Six of the farms were adjacent to forest habitat, and six were spatially isolated from forest; farms were sampled in both the dry (flowering) and the rainy (non-flowering) seasons. On adjacent farms, Hymenoptera samples taken in coffee and forest habitat were also compared. Finally, we also conducted pollinator observations in each type of farm, comparing Hymenoptera visitors to coffee plants in adjacent vs. isolated farms. Our results revealed an interaction in hymenopteran diversity between farm isolation and season, suggesting that both forest and coffee habitats play important roles at different times for Hymenoptera, especially bees. [ABSTRACT FROM AUTHOR]

Approximately 197 species comprise the widespread syrphid tribe, the Cerioidini (Diptera: Syrphidae), but rearing data are known for <5% of species. We obtained puparia of 10 species from fieldwork in Costa Rica. Cuba, and México and from material loaned to us from Australia, Brazil, Costa Rica, and the United States. These species are included in four of the five genera recognized in the tribe: two species of Ceriana Rafinesque, 1815; three species of Monoceromyia Shannon, 1925; four of Polybiomyia Shannon, 1925; and one species of Sphiximorpha Rondani, 1850. We describe and compare these puparia. They all possessed the diagnostic characters for the tribe. However, no early stage characters were correlated, hence early stages did not form groups based on shared characters. Some structures were relatively constant in form such its head skeletons and locomotory organs, but characters that showed plasticity included integumental vestiture and respiratory, organs. A few features such as the unusually broader than long posterior respiratory process of Ceriana ornotta Saunders, 1845, the spicules on the dorsum of the prothorax of Sphiximorpha barbipes (Loew, 1853), and the mesothoracic hooks of Monoceromyia tricolor (Loew, 1861) were unique to these species. Most cerioidine larvae were reared from tree sap but others crone from tree holes, the liquid center of a cut agave (Agavaceae) and bee nests (Hymenoptera, Apidae). Field observations of larvae and their breeding site suggested functional explanations for some morphological features. [ABSTRACT FROM AUTHOR]

We investigated several aspects of the nesting biology of Epicharis metatarsalis Friese (Hymenoptera: Apidae) in a lowland wet-forest of northeastern Costa Rica. Five large aggregations were found 30-100 m from larger rivers at the La Selva Biological Station. The relatively short nesting season, from May to August, indicates that E. metatarsalis is probably univoltine. Four nests were excavated to study nest architecture, and five brood cells from three different nests were analyzed for pollen composition. Additionally, we analyzed pollen loads from 33 females returning from pollen-collecting trips, and we observed male patrolling behavior. The canopy tree Apeiba membranacea Spruce ex Benth (Tiliaceae) was found to be the principal pollen source, representing an average proportion of 98.5% of each pollen load and 93.4% of the larval provisions. The brood cell with the lowest proportion of A. membranacea pollen contained 89.3% A. membranacea pollen, which was 98.5% by relative volume. Pollen of Byrsonima crispa A. Juss. (Malpighiaceae) was the second most frequently encountered pollen with average proportions of 1.3 and 4.9% in pollen loads and larval provisions, respectively. E. metatarsalis can thus be considered oligolectic. The E. metatarsalis nesting season coincides with the relatively short flowering season of B. crispa, perhaps because of the importance of B. crispa as a source of oils rather than nectar. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to examining the impact of distance to forest, tree management and floral resources on bee communities in various pastures in southern Costa Rica. About 21 study sites were selected in open pastures with an active grazing rotation. Proximity to native habitat has been known to increase the diversity of bees visiting target plant species. It was found that bee diversity or abundance did not depend on pasture management or floral resources. The populations of many bee species were found to change considerably from year to year.