Climate change could threaten newly described ‘shiny’ North American bees
Sri Lanka, an Indian Ocean island, lies far away from the United States and is just one-sixth the size of California. But interestingly, one of the three newly identified wild bee species described in California has been bestowed with a Sinhala name, a language exclusive to Sri Lanka.
All three bees look alike and display an unusual metallic sheen on their body, so one of them was named Lasioglossum (Sphecodogastra) dilisena, as the word dilisena means “shining” in the Sinhala language. Thilina Hettiarachchi, a PhD student at the University of Manitoba in Canada and the first author of the study, suggested the inclusion.
“Given that Thilina hails from Sri Lanka, it seemed apt to have a Sinhala word incorporated into one of the names, as scientific names are typically in Latin or Latinized Greek, which most people in North America may not speak. Then there’s no particular reason why Sinhala would be any less understandable,” said Jason Gibbs, associate professor of entomology at Manitoba University who is Hettiarachchi’s supervisor and a study co-author. “We strive to find names for new species that are descriptive, easy to pronounce and celebrate diversity, and the word ‘dilisena’ embodies all these features,” Gibbs told Mongabay.
Part Sinhala name
Given the metallic sheen that gives the bee’s body its iridescence, the team has aptly named the second bee as Lasioglossum (Sphecodogastra) iridescens, highlighting its iridescent nature and the color reflected by its metallic sheen. The third bee has been named Lasioglossum (Sphecodogastra) silveirai, paying tribute to the late Fernando Silveira of the Federal University of Minas Gerais for his significant contribution to bee taxonomy.
In the research paper featured in a special volume of Zootaxa, dedicated to Silveira, Gibbs said, “Silveira’s warm, jovial spirit made attending international conferences on pollinators a delight.” He added: “I first encountered Silveira at a bee
conference during my graduate studies. While I often felt intimidated by many of the senior scientists present, Silveira’s demeanor immediately put me at ease.”
Gibbs’ research interests lie in studying systematics and diversity, and he has already delved into reviewing the taxonomy of the genus Lasioglossum in North America. Gibbs has delegated the task of revision for the L. (Hemihalictus) bees of Western North America to Hettiarachchi. While working on this Western North American L. (Hemihalictus) revision, Hettiarachchi recognized this problematic species complex in L. (Sphecodogastra) and has included it as one chapter of his thesis.
In science, a genus represents a grouping of species that share common characteristics. While there are several wild bee genera, Lasioglossum stands out with the highest number of recorded bees, boasting more than 1,900 species. Consequently, taxonomic challenges arise, including instances of misidentification or overlooking new species, as demonstrated by the discovery of three new species. Due to the vastness of the Lasioglossum genus, it has been further subdivided into several subgenera, with Sphecodogastra being one such subgenus under Lasioglossum.
There are additional intriguing facets to this discovery. The study was conducted through examinations of specimens collected by various entomologists in the past. However, many of the specimens pivotal to these discoveries were collected by Philip Hunter Timberlake, an uncle of former U.S. President Richard Nixon, who resided in California, Gibbs added. Nevertheless, Timberlake was known for his notoriously difficult-to-read handwriting. “Consequently, Thilina and I had to invest a significant amount of time deciphering his handwritten labels,” Gibbs said.
Threatened pollinators
Despite their crucial role as pollinators, bees face significant threats worldwide. Habitat loss stands as the primary threat, but a range of other challenges exists, spanning from pollution to invasive species. While bees are vulnerable to insecticides, herbicides can also diminish their foraging opportunities. What researchers have recently grasped is that fungicides pose a problem as well, disrupting microbial interactions in the bees’ pollen and nectar provisions, Gibbs explained.
Climate change poses an imminent threat to biodiversity, potentially disrupting the plants, temperature patterns, and environmental signals to which local bees have adapted. While mobile organisms like bees may have the ability to relocate to evade a warming climate, those accustomed to higher elevations, such as the recently identified bees, may struggle to adapt as they reach the limits of their habitat. With limited options for further upward migration, these organisms face heightened vulnerability. Locally, there are no clear-cut strategies to mitigate these risks. What is essential, Gibbs told Mongabay, is large-scale, coordinated efforts to mitigate climate change.
Meanwhile, in Sri Lanka, experts emphasize the necessity for more research on wild bees. Although the country is home to 159 species of wild bees, the majority of research has been focused on a handful of commercially important species in agriculture, according to Inoka Karunaratne, a professor of zoology at the University of Peradeniya. Only six of these species are honeybees, producing honey and exhibiting a predominantly social structure with a queen, worker bees and male bees assigned specific tasks.
Conversely, the remaining wild bees — more than 95% — are solitary bees, commonly known as “pollen bees’” that do not form hives and receive minimal attention, despite their vital role in pollination, Karunaratne noted. These solitary bees typically nest on the ground or in cavities in wood or stems. They collect and carry pollen on their body and place it in small holes called “cells” in the nest burrow before laying an egg. “Bee species prefer different habitats, having different flowering plant species and nesting places, and if the correct environment is provided, many can still thrive,” Karunarathne said.
Disparity in interest levels
When compared with bee studies in North America, Hettiarachchi observed a significant disparity in the level of interest and overall investment in entomological research in Sri Lanka. While numerous undescribed species still exist, particularly in North America, the majority of known species there are securely identified by scientific names. Furthermore, various museums in North America house well-curated and organized collections, which serve to promote further studies in the field.
In North America, many local- and national-level entomological societies serve as valuable platforms for students and researchers, facilitating the seamless sharing of their findings with an audience that shares the same passion for insects.
While in Sri Lanka, Hettiarachchi endeavored to promote pollinator-friendly landscapes. “We can attract bees to our gardens by planting bee-friendly trees that bear flowers that are rich in nectar and pollen, besides providing shelter to the bees,” Hettiarachchi added. Collaborating with Dilmah Conservation, Hettiarachchi worked to advocate for the Solitary Bee Hotel concept in Sri Lanka, offering specially designed shelters for solitary bees.
A solitary bee house, also known as a bee hotel, consists of short tunnels and cavities where female solitary bees can lay their eggs. These structures are typically made from materials such as wood and sticks, including hollow bamboo sections, which provide suitable nesting sites. Placing these bee houses in the appropriate locations within a garden can attract these friendly pollinators and provide them with essential nesting opportunities.
Additionally, the recent paper contains an updated key for the North American Lasioglossum subgenera, which will be invaluable to ecologists and conservationists to be able to properly identify the myriads of small bees that are often the dominant, but unfortunately overlooked, pollinators in many natural and agricultural ecosystems.
Banner image: The recently described bees belong to the genus Lasioglossum and record the largest number of wild bees like this live specimen of different species in the subgenus Lasioglossum (Dialictus). Image courtesy of Thilina Hettiarachchi.
Citation:
Hettiarachchi, T., Gibbs, J.(2024). A problematic species complex for Lasioglossum subgeneric diagnostics in North America (Hymenoptera: Halictidae). Zootaxa, 5404 (1): 206–235. doi: 10.11646/zootaxa.5404.1.13
