John S. Ascher

National University of Singapore | NUS · Department of Biological Sciences

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α-diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ-diversity), either due to reduced β-diversity amplifying diversity loss or increased...

To date, the knowledge of bee diversity in the Baja California Peninsula has primarily relied on large, sporadic expeditions from the first half of the 20th century. To address the knowledge gaps, we conducted extensive fieldwork from 2019 to 2023, visited entomological collections in Mexico and USA, and accessed digital databases and community sci...

Davidson, GWH, Gan, JWM, Huang D, Hwang WS, Lum SKY & Yeo DCJ. (Eds.)

Foraging behavior frequently plays a major role in driving the geographic distribution of animals. Buzzing to extract protein-rich pollen from flowers is a key foraging behavior used by bee species across at least 83 genera (these genera comprise ~58% of all bee species). Although buzzing is widely recognized to affect the ecology and evolution of...

Bees and the ecosystem services they provide are vital to urban ecosystems, but little is understood about their distributions, particularly in the Asian tropics. This is largely due to taxonomic impediments and limited inventorying, monitoring, and digitization of occurrence records. While expert collections (EC) are demonstrably insufficient by t...

Bees of the tribe Anthidiini (Apoidea: Megachilidae) are notable pollinators consisting of resin bees, wool-carder bees, and cleptoparasitic bees. Twelve anthidiine species were historically reported in Thailand, though the taxonomic information of the group was needed revising. In this study, 165 (97♀, 68♂) anthidiine bee specimens deposited at th...

There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared. We c...

Species occurrence data are foundational for research, conservation, and science communication, but the limited availability and accessibility of reliable data represents a major obstacle, particularly for insects, which face mounting pressures. We present BeeBDC, a new R package, and a global bee occurrence dataset to address this issue. We combin...

Urban garden spaces are potentially important habitats for bee conservation. Gardens can host diverse flora, which provide floral resources across foraging seasons for bee species. Recent reviews have focused on the impacts of cityscapes on urban bee assemblages in different green spaces. Urban gardens are distinct from other urban green spaces, an...

NOTE: This manuscript and the package behind it are still undergoing tests and development. Once these are complete and a final version is accepted we will update the input data, package versions, and rerun all queries (values will change). Please contact James for further queries of collaborations in the meantime. Abstract: Species occurrence da...

The challenges of bee research in Asia are unique and severe, reflecting different cultures, landscapes, and faunas. Strategies and frameworks developed in North America or Europe may not prove applicable. Virtually none of these species have been assessed by the IUCN and there is a paucity of public data on even the basics of bee distribution. If...

Aim Mining is increasingly pressuring areas of critical importance for biodiversity conservation, such as the Brazilian Amazon. Biodiversity data are limited in the tropics, restricting the scope for risks to be appropriately estimated before mineral licensing decisions are made. As the distributions and range sizes of other taxa differ markedly fr...

Research studies and conservation actions aimed at improving conditions for bees require a basic understanding of which species are present in a given region. The US state of Minnesota occupies a unique geographic position at the confluence of eastern deciduous forests, northern boreal forests, and western tallgrass prairie, which has led to a dive...

Chile's isolation and varied climates have driven the evolution of a unique biodiversity with a high degree of endemism. As a result, Chile encompasses diverse environments, including the Mediterranean-type ecosystem, a global biodiversity hotspot. These environments are currently threatened by anthropogenic land use change impacting the integrity...

Native bee species in the United States provide invaluable pollination services. Concerns about native bee declines are growing, and there are calls for a national monitoring program. Documenting species ranges at ecologically meaningful scales through coverage completeness analysis is a fundamental step to track bees from species to communities. I...

Species are fundamental biological units, but their discovery and delimitation requires appropriate data and methods. To better circumscribe species, we must improve our species concepts and bolster the underlying data resources necessary to enact them. Here, we provide six prescriptions for better collecting and synergizing our knowledge on specie...

Species are fundamental biological units, but their discovery and delimitation requires appropriate data and methods. To better circumscribe species, we must improve our species concepts and bolster the underlying data resources necessary to enact them. Here, we provide six prescriptions for better collecting and synergizing our knowledge on specie...

To examine changes in bee communities and bee-flower relations in the Prairie Pothole Region of the Northern Great Plains, we compared bee specimens and their floral associations collected in eastern North Dakota during 2010-2012 to bee specimens and their floral associations collected from the same region during 1910-1920 by pioneering naturalist...

This is an eletter to comment on Ma's letter (Science 377, 6610).

Chile’s isolation and varied climates have driven the evolution of a unique biodiversity with a high degree of endemism. The Mediterranean-type biome of Central Chile is one of 35 global biodiversity hotspots and has been highlighted as one of Chile’s most endangered areas. It is threatened by anthropogenic land use change impacting the integrity o...

Climate change (CC) is expected to negatively impact global biodiversity and ecosystems, resulting in profound ecological impacts and placing complex networks of biological interactions at risk. Despite this worrying scenario, the existing knowledge deficiencies may be overcome with species distribution models (SDMs), providing estimates of the eff...

Article URL: https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/2022/01/RBZ-2022-0004.pdf Reports of global bee declines have raised an urgent call for assessments of the conservation status of these key pollinators. The first published checklist and conservation status assessment for the bee fauna of a Southeast Asian country is presented here...

Nectar is one of the most important resources used by bees. It has long been known that some bees concentrate nectar externally with their mouthparts, including honey bees and stingless bees. However, observations of this behavior in disparate bee groups suggest this behavior is widespread. Here, we combine accounts and images from publications, co...

Increasing crop configurational heterogeneity—smaller crop fields with more field margins—has been repeatedly found to support farmland biodiversity. But research on compositional crop heterogeneity—the number and evenness of crop types—has usually shown only weak effects. However, much of this research has been conducted in large‐scale temperate a...

Resin bees of the subgenus Ranthidiellum, are rare and endemic to Southeast Asia. These bees are known to construct resinous entrance tubes to their nests. Here, the new species Anthidiellum (R.) phuchongensis sp. nov. is described along with a description of its nest collected from Phu Chong Na Yoy National Park, Ubon Ratchathani Province, Thailan...

Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragm...

Morocco is a well known hot-spot of biodiversity in the Mediterranean basin. While some taxa like vascular plants are relatively well recorded, important groups of pollinators like bees are still understudied. This article presents an updated checklist of the bee species of Morocco and includes a summary of global and regional distribution of each...

Citation: Chatthanabun N, Ascher JS, Pinkaew N, Thanoosing C, Traiyasut P, Warrit N (2020) Resin bees of genus Megachile, subgenera Callomegachile and Carinula (Hymenoptera, Megachilidae) from Thailand with description of a new species. ZooKeys 997: 95-144. https://doi. Abstract Resin bees of the genus Megachile subgenus Callomegachile sensu lato (...

Insects are the focus of many recent studies suggesting population declines, but even invaluable pollination service providers such as bees lack a modern distributional synthesis. Here, we combine a uniquely comprehensive checklist of bee species distributions and >5,800,000 public bee occurrence records to describe global patterns of bee biodivers...

Our City in Nature would not be complete without the array of beautiful bee species that serve as some of our most important pollinators. A collaboration between the National Parks Board and the University of Singapore, this guide reveals the remarkable diversity of bees found in various habitats across Singapore, from tiny honey-producing stingles...

The Chinese bees of the genus Anthidium Fabricius, 1804, are reviewed. Twenty-one species are confirmed to occur in China, five of which are described and illustrated as new Chinese endemics: Anthidium (Anthidium) pseudomontanum Niu & Zhu, sp. nov., A. (A.) pseudophilorum Niu & Zhu, sp. nov., A. (A.) tasitiense Niu & Zhu, sp. nov., A. (A.) xuezhong...

Our objective was to examine how bee foraging preferences on dioecious willows are influenced by plant sex, time of day, by sampling date on multiple sites and across different willow species. In a common garden experiment examining diurnal pollinator visitation patterns of Andrena bees (andrenids), there was a strong preference for male willow pla...

The Wallacean shortfall—lack of adequate knowledge of a species’ distribution in the geographic space—hinders practical actions towards species conservation, and such severe data deficit is ubiquitous when dealing with insect species. Considering the effects of human activities on Earth, especially in the last 50 years, proper delimitation of speci...

In their article entitled “Climate change contributes to widespread declines among bumblebees across continents” recently published in Science and reported upon worldwide, Soroye, Newbold & Kerr (1) used extensive specimen records to explore patterns of geographic range loss and expansion of bumble bees in Europe and North America, and, in line wit...

Five Chinese species of Nomia (Gnathonomia) Pauly, 2005 are treated in this paper: Nomia fusciventris Zhang & Niu, sp. nov. from Fujian Province is described as a new species; N. aurata Bingham, 1897 and N. wahisi Pauly, 2009 are recorded from China for the first time, and the male of N. pieli Cockerell, 1931 is newly reported. An updated diagnosis...

Cyprus, the third largest island in the Mediterranean, constitutes a biodiversity hotspot with high rates of plant endemism. The wild bees of the island were studied extensively by the native George Mavromoustakis, a world-renowned bee taxonomist, who collected extensively on the island from 1916 to 1957 and summarised his results in a series of ei...

The science of taxonomy faces many challenges at present. Many questions remain as to how we can best continue the vital practice of describing and understanding biodiversity. Here, we discuss how best to modernize taxonomy, how we might improve taxonomy in developing countries, and how taxonomists can better interface with other fields to better s...

Species invasions are expected to increase continuously with undeniable impact upon native biodiversity, being an important process in relation to the decline of native pollinators. We used species distribution models and multivariate analyses to assess the climatic niche properties of the red dwarf honey bee, Apis florea Fabricius (Apidae: Apini),...

A preliminary study of leaves cut by Megachile leafcutter bees were documented in Singapore through photographic surveys from March to August 2014 (86 observations), pressed leaves from 2016 to 2019 (51 observations), and crowd-sourced photographs from 2017 to 2019 (24 observations). Of the 161 plant observations, 130 were identified to species (64...

This revision of the bee genus Bathanthidium Mavromoustakis, 1953, treats 12 species, with 11 recorded from China, including Bathanthidium fengkaiense Niu & Zhu, sp. nov.. Two species are proposed as new combinations in genus Bathanthidium: Anthidium (s. str.) bicolor Wu, 2004, A. (s. str.) monganshanensis Wu, 2004. The two new combinations (B. bic...

The Chinese bees of the genus Trachusa Panzer, 1804 are reviewed. Nine species are confirmed to occur in China. Three new species are described and illustrated: Trachusa (Paraanthidium) pingdaensis Niu, sp. nov., T. (P.) staabi Niu, sp. nov. and T. (P.) wuae Niu, sp. nov. The distribution of each species is given. An illustrated key to the Chinese...

Southeast (SE) Asia holds high regional biodiversity and endemism levels but is also one of the world's most threatened regions. Local, regional and global threats could have severe consequences for the future survival of many species and the provision of ecosystem services. In the face of myriad pressing environmental problems, we carried out a r...

As a unique coastal hill dipterocarp forest remnant in Singapore, Bukit Timah Nature Reserve is a key refuge for flowering plants, but little information has been available about its bee pollinators and their floral associations. Historical and recent surveys of bees (Hymenoptera: Apoidea: Anthophila) at Bukit Timah and vicinity were compiled, yiel...

Traditional conservation techniques for mapping highly biodiverse areas assume there to be satisfactory knowledge about the geographic distribution of biodiversity. There are, however, large gaps in biological sampling and hence knowledge shortfalls. This problem is even more pronounced in the tropics. Indeed, the use of only a few taxonomic groups...

Predicting the long‐term consequences of habitat alteration for the preservation of biodiversity and ecosystem function requires an understanding of how ecological filters drive taxonomic and functional biodiversity loss. Here, we test a set of predictions concerning the role of ecological filters in restructuring native bee assemblages inhabiting...

[This corrects the article DOI: 10.1371/journal.pone.0151482.].

Presenta información sobre el conocimiento actual de la fauna de abejas de Mesoamérica, analizando las areas de las que se tiene mas información y que sitios requieren ser mejor estudiados.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Taxonomy is a scientific discipline that has provided the universal naming and classification system of biodiversity for centuries and continues effectively to accommodate new knowledge. A recent publication by Garnett and Christidis [1] expressed concerns regarding the difficulty that taxonomic changes represent for conservation efforts and propos...

Megachile laticeps cutting leaf of Dendrolobium umbellatum

Reports of world-wide decline of pollinators, and of bees in particular, raise increasing concerns about maintenance of pollination interactions. While local factors of bee decline are relatively well known and potential mitigation strategies at the landscape scale have been outlined, the regional and continental-scale threats to bee diversity have...

Findings 1. Blue vane traps, colored bowl/cup traps and hand-netting along transects are adept at capturing thousands of bee pollinators to biomonitor sensitive ecological responses to perturbation to the insect community. 2. These trapping methods can be integrated and incorporated by solar energy personnel and ecologists into a functioning USSE f...