Saturday, April 11, 2026

SoCal honeybees can fend off deadly mites

Hybrid species exhibits unusual defenses

University of California - Riverside

Wild hive — image:
Southern California hybrid honeybee hive hanging from a tree in the wild.
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Credit: Boris Baer/UCR

Southern California is home to a flying black and yellow treasure. While commercial honeybee hives nationwide are collapsing under attack from deadly parasites, a unique hybrid bee found only in this part of the state has demonstrated the ability to survive.

U.S. beekeepers reported losing up to 62% of their managed honeybee colonies in 2025, which threatens our food supply. The losses are driven by a combination of pesticides, climate pressure, habitat loss, and parasites, with the Varroa mite among the most destructive of these factors.

Varroa mites feed on honeybees’ fat body tissue, which weakens their immune systems, reduces their body weight, and shortens their lives. The fat body is an organ in bees that, if you were comparing it to human biology, performs the functions of the liver, pancreas, and immune system.

The mites also act as vectors for deadly viruses like Deformed Wing Virus and Acute Bee Paralysis Virus, which they transmit directly into a bee’s bloodstream. Beekeepers rely on chemical treatments for suppression that can lose effectiveness over time.

A new study from UC Riverside published in Scientific Reports is the first to show that a locally adapted population of honeybees can naturally and consistently suppress the mites.

“We kept hearing anecdotally that these Californian honeybees were surviving with way fewer treatments. I wanted to test them rigorously and understand the driving force behind what the beekeepers were seeing,” said Genesis Chong-Echavez, a UCR graduate student and lead author of the study.

Alongside entomologists from UCR’s Center for Integrative Bee Research (CIBER), Chong-Echavez monitored 236 honeybee colonies between 2019 and 2022.

The Californian bees were not entirely immune to the mites. However, colonies headed by locally raised Californian hybrid honeybee queens had about 68% fewer mites on average than colonies headed by commercial honeybee queens. They were also more than five times less likely to cross the threshold at which chemical treatments become necessary.

The bees in the study are not a commercial breed. They come from a genetically mixed population of honeybees established in Southern California, often from feral colonies living in trees. Recent research shows they are a hybrid population with ancestry from at least four honeybee lineages, including African, Eastern European, Middle Eastern, and Western European bees.

To more fully understand the bees’ resistance to the mites, the researchers also ran laboratory experiments with developing honeybee larvae. Varroa mites must enter brood cells to reproduce, so the team tested whether mites were equally drawn to larvae from commercial and Californian hybrid honeybee colonies.

They were not.

Mites were less attracted to the Californian hybrid honeybee larvae, especially at seven days old, the stage when mites are normally most likely to invade. The finding suggests the bees’ secret to fending off mites lies in early development, before any adult worker behaviors might come into play.

“What surprised me most was the differences showed up even at the larval stage,” Chong-Echavez said. “This suggests the resistance mechanism may go deeper than some kind of behavior and may be genetically built into the bees themselves.”

The findings could have implications beyond Southern California. Honeybees pollinate crops worth billions of dollars and are under growing pressure from multiple environmental stressors. The research suggests that part of the answer to improving honeybee health may lie in the biology of these bees.

Boris Baer, UCR entomology professor and co-author of the study, said the study also highlights the value of listening to working beekeepers.

“This question did not start in the lab. It started in conversations with beekeepers,” Baer said. “They were not just observers; they helped shape the questions behind this research.”

The researchers caution that the Californian hybrid honeybees are not entirely mite-free, and they do not suggest abandoning current management practices. Instead, they hope to learn which traits help these honeybees keep mite levels lower, and whether those traits could support future breeding programs or reduce dependence on chemicals.

Next, the team plans to investigate the genetic, behavioral, and chemical signals that may make the larvae less attractive to mites.

“At a time when pollinators are facing global decline, this work offers a hopeful message: solutions may already be emerging in the field, and we just need to understand them,” Chong-Echavez said.

A Varroa mite on a developing honeybee larva inside a brood cell.

Researchers inspecting honeybee colonies as part of long-term monitoring of Varroa mite infestations.

Credit

Genesis Chong-Echavez/UCR

Journal

Scientific Reports

DOI

10.1038/s41598-026-45759-9

Article Title

Varroa mite resistance in a hybrid honey bee (Apis mellifera) population in Southern California

The Local Universe’s Expansion Rate Is Clearer Than Ever, But Still Doesn’t Add Up

Artist’s interpretation of the cosmic distance ladder — a succession of overlapping methods used to measure distances across the Universe, where each rung of the ladder provides information that can be used to determine the distances at the next higher rung. Methods include observations of pulsating Cepheid variable stars, red giant stars that shine with a known brightness, Type Ia supernovae, and certain types of galaxies. In this illustration, the distance ladder begins at the Coma Cluster, which is the nearest extremely rich galaxy cluster to us. The distance to the Coma Cluster can be measured directly using observations of Type Ia supernovae within the cluster. Type Ia supernovae have a predictable luminosity that makes them reliable objects for distance calculations.

CREDIT: CTIO/NOIRLab/DOE/NSF/AURA/J. Pollard Image Processing: D. de Martin & M. Zamani (NSF NOIRLab)

April 11, 2026
By Eurasia Review

An international collaboration of astronomers has produced one of the most precise measurements yet of how fast the local Universe is expanding. The result deepens one of the most significant challenges in modern cosmology. John Blakeslee, astronomer at NSF NOIRLab, funded by the U.S. National Science Foundation, is a member of the collaboration, and telescopes across two NSF NOIRLab Programs contributed data.

Astronomers have sought to measure the expansion rate of the Universe using two fundamentally different approaches. One method relies on measuring distances to stars and galaxies in the nearby Universe. The other uses measurements of the cosmic microwave background to predict what the expansion rate would be today under the standard model of cosmology.

These two approaches are expected to yield the same result, but they don’t. Measurements based on the nearby Universe consistently indicate a higher expansion rate — around 73 kilometers per second per megaparsec — while predictions derived from the early Universe yield a lower value, closer to 67 or 68. Although the numerical difference is modest, it is far larger than can be explained by statistical uncertainty. This persistent disagreement, known as the Hubble tension, has now been observed across multiple independent studies and techniques.

By bringing together decades of independent observations into a single, unified framework, an international collaboration of astronomers has achieved the most precise direct measurement to date of the expansion rate of the nearby Universe. In a paper published in Astronomy & Astrophysics, the H0 Distance Network (H0DN) Collaboration reports a value of the Hubble constant of 73.50 ± 0.81 kilometers per second per megaparsec, corresponding to a precision of just over 1%.

The study, “The Local Distance Network: a community consensus report on the measurement of the Hubble constant at ∼1% precision,” is the outcome of a broad community effort launched at the International Space Science Institute (ISSI) Breakthrough Workshop, “What’s under the H0od?”, held at ISSI in Bern, Switzerland, in March 2025.

“This isn’t just a new value of the Hubble constant,” the collaboration notes, “it’s a community-built framework that brings decades of independent distance measurements together, transparently and accessibly.”

NSF NOIRLab contributed both expertise and observational data to this effort. John Blakeslee, astronomer and Director of Research and Science Services at NSF NOIRLab, is a member of the collaboration. The study includes data from telescopes at NSF Cerro Tololo Inter-American Observatory (CTIO) in Chile and NSF Kitt Peak National Observatory (KPNO) in Arizona, both Programs of NSF NOIRLab. Those data were incorporated into a broader, collaborative framework spanning both ground and space-based observatories, helping to strengthen the overall result.

Rather than relying on a single method, the team constructed a “distance network” that links many overlapping techniques for measuring distances across the local Universe. These include observations of pulsating Cepheid variable stars, red giant stars that shine with a known brightness, Type Ia supernovae, and certain types of galaxies. This approach enables multiple independent paths to the same final result, and allows for a critical test: is the discrepancy caused by an error within a single method? The results indicate that this is unlikely. Even when individual techniques are removed from the analysis, the overall result changes only minimally. Independent measurements remain consistent with one another, reinforcing the robustness of the locally measured expansion rate.

“This work effectively rules out explanations of the Hubble tension that rely on a single overlooked error in local distance measurements,” the authors conclude. “If the tension is real, as the growing body of evidence suggests, it may point to new physics beyond the standard cosmological model.”

The implications are significant. The lower expansion rate inferred from the early Universe depends on the standard model of cosmology, which describes how the Universe has evolved since the Big Bang. If that model is incomplete — for example, if it does not fully account for the behavior of dark energy, new particles, or modifications to gravity — its predictions for the present-day expansion rate would be affected.

In that case, the Hubble tension may not be the result of measurement error, but rather evidence that the current model of the Universe is missing a key component. The local distance network also establishes a framework for future investigations. By making its methods and data openly available, the collaboration has created a foundation that can be expanded with new observations. With next-generation observatories expected to provide even more precise measurements, astronomers aim to determine whether this discrepancy will ultimately be resolved or continue to point toward new physics.

The local universe’s expansion rate is clearer than ever, but still doesn’t add up

A new synthesis of astronomical measurements confirms a persistent mismatch that could point to physics beyond current models

Association of Universities for Research in Astronomy (AURA)

image:
Artist’s interpretation of the cosmic distance ladder — a succession of overlapping methods used to measure distances across the Universe, where each rung of the ladder provides information that can be used to determine the distances at the next higher rung. Methods include observations of pulsating Cepheid variable stars, red giant stars that shine with a known brightness, Type Ia supernovae, and certain types of galaxies.
In this illustration, the distance ladder begins at the Coma Cluster, which is the nearest extremely rich galaxy cluster to us. The distance to the Coma Cluster can be measured directly using observations of Type Ia supernovae within the cluster. Type Ia supernovae have a predictable luminosity that makes them reliable objects for distance calculations.
view more
Credit: CTIO/NOIRLab/DOE/NSF/AURA/J. Pollard Image Processing: D. de Martin & M. Zamani (NSF NOIRLab)

An international collaboration of astronomers has produced one of the most precise measurements yet of how fast the local Universe is expanding. The result deepens one of the most significant challenges in modern cosmology. John Blakeslee, astronomer at NSF NOIRLab, funded by the U.S. National Science Foundation, is a member of the collaboration, and telescopes across two NSF NOIRLab Programs contributed data.

Astronomers have sought to measure the expansion rate of the Universe using two fundamentally different approaches. One method relies on measuring distances to stars and galaxies in the nearby Universe. The other uses measurements of the cosmic microwave background to predict what the expansion rate would be today under the standard model of cosmology.

These two approaches are expected to yield the same result, but they don’t. Measurements based on the nearby Universe consistently indicate a higher expansion rate — around 73 kilometers per second per megaparsec — while predictions derived from the early Universe yield a lower value, closer to 67 or 68. Although the numerical difference is modest, it is far larger than can be explained by statistical uncertainty. This persistent disagreement, known as the Hubble tension, has now been observed across multiple independent studies and techniques.

By bringing together decades of independent observations into a single, unified framework, an international collaboration of astronomers has achieved the most precise direct measurement to date of the expansion rate of the nearby Universe. In a paper published on 10 April in Astronomy & Astrophysics, the H0 Distance Network (H0DN) Collaboration reports a value of the Hubble constant of 73.50 ± 0.81 kilometers per second per megaparsec, corresponding to a precision of just over 1%.

The study, “The Local Distance Network: a community consensus report on the measurement of the Hubble constant at ∼1% precision,” is the outcome of a broad community effort launched at the International Space Science Institute (ISSI) Breakthrough Workshop, “What’s under the H0od?”, held at ISSI in Bern, Switzerland, in March 2025.

“This isn’t just a new value of the Hubble constant,” the collaboration notes, “it’s a community-built framework that brings decades of independent distance measurements together, transparently and accessibly.”

NSF NOIRLab contributed both expertise and observational data to this effort. John Blakeslee, astronomer and Director of Research and Science Services at NSF NOIRLab, is a member of the collaboration. The study includes data from telescopes at NSF Cerro Tololo Inter-American Observatory (CTIO) in Chile and NSF Kitt Peak National Observatory (KPNO) in Arizona, both Programs of NSF NOIRLab. Those data were incorporated into a broader, collaborative framework spanning both ground and space-based observatories, helping to strengthen the overall result.

Rather than relying on a single method, the team constructed a “distance network” that links many overlapping techniques for measuring distances across the local Universe. These include observations of pulsating Cepheid variable stars, red giant stars that shine with a known brightness, Type Ia supernovae, and certain types of galaxies. This approach enables multiple independent paths to the same final result, and allows for a critical test: is the discrepancy caused by an error within a single method? The results indicate that this is unlikely. Even when individual techniques are removed from the analysis, the overall result changes only minimally. Independent measurements remain consistent with one another, reinforcing the robustness of the locally measured expansion rate.

“This work effectively rules out explanations of the Hubble tension that rely on a single overlooked error in local distance measurements,” the authors conclude. “If the tension is real, as the growing body of evidence suggests, it may point to new physics beyond the standard cosmological model.”

The implications are significant. The lower expansion rate inferred from the early Universe depends on the standard model of cosmology, which describes how the Universe has evolved since the Big Bang. If that model is incomplete — for example, if it does not fully account for the behavior of dark energy, new particles, or modifications to gravity — its predictions for the present-day expansion rate would be affected.

In that case, the Hubble tension may not be the result of measurement error, but rather evidence that the current model of the Universe is missing a key component. The local distance network also establishes a framework for future investigations. By making its methods and data openly available, the collaboration has created a foundation that can be expanded with new observations. With next-generation observatories expected to provide even more precise measurements, astronomers aim to determine whether this discrepancy will ultimately be resolved or continue to point toward new physics.

More information

This research is presented in a paper titled “The Local Distance Network: A community consensus report on the measurement of the Hubble constant at ∼1% precision” to appear in Astronomy & Astrophysics. DOI: 10.1051/0004-6361/202557993

The results are presented by the H0DN Collaboration.

NSF NOIRLab, the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), NSF Kitt Peak National Observatory (KPNO), NSF Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona.

The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.

The International Space Science Institute (ISSI) is an Institute of Advanced Studies, where scientists from all over the world meet in a neutral, welcoming, and multi-disciplinary setting to discuss and publish about relevant and compelling topics related to four Disciplines: Astrophysics, Heliophysics, Planetary Science and Earth Science. ISSI’s mission is to advance science by facilitating scientific community interactions, meetings, discussions, and publications aimed at a deeper understanding of results from different space missions, ground-based observations, and theory. This is achieved through a broad portfolio of scientific opportunities that include: International Teams, Workshops, Working Groups, Fora, or visits of individual Visiting Scientists. For additional information related to ISSI and to the opportunities it offers, see: www.issibern.ch.