Ground-Nesting Bee

A huge thank you to everyone who has joined the community this far! Thanks to you, we have collected over 1200 observations from over 650 people across the world, and this is just the beginning. Continue to keep an eye out for nesting bees around you and be sure to record your observations on iNaturalist. Consider visiting sites reported by other citizen scientists as well! Once again thank you and here’s to continuing to grow our understanding and appreciation of these amazing organisms! #citizenscience #conservation #bees #entomology #inaturalist #nature #nativebees

Species: Centris rhodophthalma Location: San Felipe de Aconcagua, Valparaíso, Chile Photo credit:© sebastian-andrade-t, all rights reserved Centris rhodophthalma (Pérez, 1911) is a solitary oil-collecting bee endemic to Chile, occurring from the Atacama Region south through Valparaíso. It belongs to the subgenus Wagenknechtia, a lineage of Andean Centris bees characterized by females possessing specialized foreleg structures used for harvesting floral oils. Morphologically, C. rhodophthalma has dark brown head, mesosoma, and legs; the metasoma exhibits bluish-violet metallic reflections and dense brownish pilosity, and the species is notable for its distinctive reddish compound eyes. Like other Centris bees, it is associated with oil-producing flowers and serves as an important pollinator in xeric and semi-arid ecosystems. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Early Mining Bee (Andrena haemorrhoa) Location: Fovslet Mark, South Denmark, Denmark Photo Credit: © Erland Refling Nielsen, some rights reserved (CC-BY-NC) From erlandreflingnielsen about Andrena haemorrhoa, who observed these bees mating in his own garden: “The mating took a little more than four minutes, starting with the male landing on the female perched on a leaf. They quickly connected and were more or less motionless. The female, after more than three minutes, seemed to think the male was done, and she used her hind legs to push him away. That did not seem effective, so she curled up and used her mandibles to get rid of the male.” Early mining bees are early spring bees that can be seen from March to June. Females generally nest alone, though they do sometimes nest in small groups. They can be distinguished by their foxy-brown hairs on their thorax, while males are smaller and have much lighter hair. In the first image, the female is pictured on the right, while the male is connected behind. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Anthophora fulvitarsis Location: Enbekshikazakh District, Kazakhstan Credit: © Paul Geisendörfer, some rights reserved (CC-BY-NC) These images were captured by Paul Geisendörfer, a freelance taxonomist specializing in the Anthophorinae. His recent, self-funded expedition to the Enbekshikazakh District of Kazakhstan reflects his ongoing efforts to expand taxonomic work into Central Asia, an understudied region for this group. Through detailed nest excavations, Paul investigates the nesting biology and phenology of Anthophora species. His observations of Anthophora fulvitarsis provide a rare glimpse into its life cycle, including overwintering as a fully developed adult within the nest—a strategy revealed when an imago female emerged during excavation. This post highlights Anthophora fulvitarsis and their brood cells by a river bank in Kazakhstan. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Megachile (Eutricharaea) basalis Smith Location: Erongo Region, Namibia Credit: © Bryan Danforth, some rights reserved (CC-BY-NC) Bryan Danforth and Silas Bossert studied a large aggregation of Megachile basalis along a dirt road at the Otjandaue hunting lodge near Omaruru, Namibia. These leaf-cutter bees are fascinating because females dig their own subterranean nests by excavating in the hard-packed, red, sandy soils. Females make rapid trips carrying a pellet of soil on each trip. They meticulously deposit the soil pellets in a pile near the nest entrance, making it very easy to find nests. Danforth and Bossert obtained leaf-lined brood cells, observed parasitism by a species of Coelioxys, and observed females foraging on Crotalaria podocarpa flowers. They will be writing up a report on the biology of this charismatic bee. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Andrena regularis Location: Ithaca NY, USA Credit: © Bryan Danforth, some rights reserved (CC-BY-NC) Project GNBee puts forth a new study that takes a close look at one of the largest known nesting aggregations of a ground-nesting bee, Andrena regularis. Using emergence traps, we tracked when bees emerge at this site—revealing an estimated ~5.5 million individuals from a single aggregation, along with clear patterns in emergence dynamics, preferential investment in females, and fascinating interactions with bee and non-bee parasites. This approach allows us to study entire bee populations directly at their nesting sites, offering a rare window into the hidden underground life-history of bee biology. This work highlights how Project GNBee is advancing the study and conservation of ground-nesting bees. By combining field research, community science, outreach, and advocacy, we are helping to identify, understand, and protect the habitats that sustain these essential pollinators. These insights are critical for supporting healthy bee populations across the landscape and strengthening pollination in both natural and agricultural systems. And next time you pass by a cemetery—take a closer look. These spaces are often important refuges for plants and wildlife and are increasingly recognized as hotspots for large populations of ground-nesting bees. 1. Graphic from Cornell Chronicle 2. Female Andrena regularis in flight 3. Female Nomada imbricata inspecting nest entrance of Andrena regularis 4. Male Andrena regularis emerging from nest for first time, 5. Female Andrena regularis on apple flower at Cornell Orchards 6. Female Andrena regularis at nest entrance 7. East Lawn Cemetery showing area of high nest density Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Think all bees live in hives? Think again! 🐝✨⁣ ⁣ Earthplace is hiding a big secret right beneath our feet: a vast underground neighborhood of rufous-backed cellophane bees! 🌸 Join us on May 23 for family fun at the Bee Brunch! Enjoy refreshments, crafts, and the chance to see these gentle native pollinators in action.⁣ ⁣ 📍 10 Woodside Lane, Westport, CT⁣ 🗓️ Saturday, May 23, 2026⁣ ⏰ 11am – 1pm⁣ 🎟️ Cost: $5 suggested donation (to protect the bees!)⁣ ⁣ Register ⁣at earthplace.org 🔗⁣ #Earthplace #BeeBrunch #WestportCT #NativeBees #FairfieldCounty @projectgnbee

Species: Lasioglossum marginatum Location: 26400 Gigors-et-Lozeron, France Credit: © Nicolas HELITAS, some rights reserved (CC-BY-NC) Lasioglossum marginatum is a eusocial species that has nests of dozens to hundreds of individuals, all produced by a single queen. Unlike other eusocial halictids, instead of a one-year life-cycle, a colony cycles every five years. As a univoltine species, only one generation is produced each year. For the first four years, the queen produces only workers until the fifth year, when future foundresses and males are produced. The queen lives for the entire five-year colony cycle, making it one of the longest-lived sweat bees in the world. Lasioglossum marginatum is found in southern Europe, with its main distribution in the Mediterranean, Central-Europe, and the Balkans. Recently, it has been observed more in the northern parts of Europe as well, potentially due to warmer temperatures from climate change. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Anthophora californica Location: Irvine Park Rd, Orange, CA, US Credit: © Braxton L., some rights reserved (CC-BY-NC) California digger bees can be distinguished by their green eyes and black abdomens with thinner, white stripes. Some males can also have reddish hind limbs with spurs that they use to fight for mates. While the common name of this species is the California Digger Bee, it can be found as far South as Oaxaca, Mexico, and as far east as Kansas, Oklahoma, and Texas. Some records on GBIF show them even further down in Southern Mexico. While solitary, female bees will be gregarious in nature and will tend to build nests next to each other, sometimes forming aggregations by the 1000s. The anthophora family in general, is notoriously fast, often seen darting across flowers. In the pocket guide, “Common Native Bees in Gardens of California”, the authors wrote about Anthophora, "These bees fly so fast, you often only see a grey streak zoom by." Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Thyreus nitidulus Location: Chelsea Rd, Ransome, QLD, AU; Cooktown QLD 4895, Australia; Bermagui NSW 2546, Australia Credit: © Tracy W, some rights reserved (CC-BY-NC), © chiaah, some rights reserved (CC-BY-NC), © debtaylor142, some rights reserved (CC-BY-NC) When it comes to nature’s most vibrant and beautiful creatures, we think neon cuckoo bees are definitely a competitor! These bees sport a metallic blue body with sleek, black wings, giving it the scientific name Thyreus nitidulus, which means ‘a little shiny’ in latin. Neon cuckoo bees are generally found in New Guinea and throughout eastern and northern Australia, and are a parasite to the blue-banded bee, Amegilla cingulata. In this post, a neon cuckoo bee and member of subgenus Zonamegilla can be found roosting face-to-face on the same stick, perhaps because they were too cold to move. Blue-banded bees are solitary bees that build burrow nests. They also lay their offspring in brood cells, which are filled with pollen for when they hatch. Neon cuckoo bees will slip in before the nest is sealed, and lay their eggs. If the neon cuckoo bee’s young hatches earlier, it will be able to eat all of the pollen, leaving the blue-banded young to starve. To our GNBee observers in Australia, keep an eye out to see if you can spot these vibrant thieves! Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Amegilla dawsoni Location: Carnarvon WA 6701, Australia; Inggarda WA 6701, Australia Credit: © lesgeorge, some rights reserved (CC-BY-NC) This past July to September in Australia, we had great observations of the largest native bee of Western Australia, Dawson’s burrowing bee. Here are some of our favorite highlights of this bee over the years! These bees are burrow nesters and can congregate in massive colonies, as pictured in this post. Although solitary, they nest in large aggregations to provide communal protection from predators. Females of this species can reach up to 23 millimeters, while males are slightly smaller. They have robust, golden-brown bodies with black and white banded abdomens. Also pictured in slide 5 are two female bees in battle. While female Dawson’s burrowing bees generally fight over nests, males will fight for mates. Pictured in slides 1 and 2, iNat observer Les explains their mating behavior: “A group of males with part of a female visible, another showing how males stack on top of each other in these mating frenzies, sometimes males attempt to mate with other males. Another shows a group of males around a hole where there is a female, when she finally comes out she will be set upon by all.” This fascinating species is facing loss from habitat loss due to climate change, agriculture, and mining. It is important to conserve this species through the protection of their habitats and further research on their ecological needs. We appreciate the continued efforts of our GNBee observers who make this work possible! Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience

Species: Mesonychium garleppi Location: Parinacota, Arica y Parinacota, Chile Photo credit:© sebastian-andrade-t, all rights reserved Mesonychium garleppi is a striking cleptoparasitic bee species found in northern Chile, from Arica and Parinacota to Antofagasta, primarily in pre-Andean and Andean habitats, with some historical coastal records. Instead of building its own nest, the female infiltrates nests of oil-collecting Centris bees, such as Centris aymara, and lays her eggs in already-provisioned brood cells. Observations of this species often involve individuals emerging from or leaving these concealed host nests, suggesting successful parasitism that enables the next generation to develop. We consider it one of the most visually remarkable bees. Learn more at GNBee.org Find us on iNAT project : Ground Nesting Bees Watch clips at: /@GroundNestingBees #bees #groundnestingbees #macrophotography #entomology #citizenscience