In lekking, certain species of males in the animal world, including black grouse, peacock and owl parrots, congregate in a courtship ritual to entice females to mate with them. This is unusual because spiders are notoriously solitary and cannibalistic.
Two UC Davis spider experts played a key role in analyzing the genetics of this spider. The new species is an orb weaver named Isoxya manangona. Its species name is derived from the Malagasy verb meaning to "gather" or "aggregate."
Jason Bond, the Evert and Marion Schlinger Endowed Chair in the UC Davis Department of Entomology and Nematology and project scientist James Starrett headed the genetic analysis. The research paper was recently published in the journal, Insect Systematics and Diversity.
“This paper is significant in a number of respects including the discovery of a new species of orb web-weaving spider that is social; most spiders are solitary predators that are cannibalistic,” said Bond, who doubles as associate dean, UC Davis College of Agricultural and Environmental Sciences. “Although additional behavioral studies are needed to confirm, what is particularly interesting about this paper is that we report what is likely the first known observation of lekking behavior in spiders.”
Ingi Agnarsson, a professor of zoology at the University of Iceland and the Smithsonian Institution, Washington, D.C., headed the international team of researchers.
While looking for bark spiders in the rainforests of Andasibe-Mantadia National Park, the scientists observed large colonies of interconnected webs, built by what they later determined to be a new species.
In examining the webs, the researchers noticed multiple males gathering close together, sometimes touching, in a central, nonsticking line. They counted up to 41 interconnected, single-cohort adult female webs with up to 38 adult males aggregating on a central, single, nonsticky line.
In all, their mile-long research area yielded 22 spider colonies, ranging from 2 to 79 spiders in webs two inches to almost eight inches in size. The spiders are dark gray with black coloring and large protruding spines. The females are about 0.2 inches in size, with “cryptic yellow markings.” The males are smaller but with no yellow markings.
“Spiders are notoriously solitary and cannibalistic, with instances of colonial or social lifestyles in only about 50-60, or ~0.1% of 50,000 described species,” the authors wrote in their abstract. “Population analyses indicate that most colonies consist of multiple cohorts formed by close relatives. Territorial social spiders facultatively form colonies by interlinking individual webs, but further cooperation is infrequent, and only among juveniles or (rarely) females. In spiders therefore, aggregations of males outside of the male-male competition context has been unknown.”
The researchers noted that the males were “resting tightly together,” but they found “no evidence” of male-male aggression. “Genetic analyses from RAD sequencing suggest that most colonies consist of unrelated individuals,” they wrote in their abstract. “Furthermore, genetic variability of males was somewhat less than that of females. Single cohort colonies made up purely of adults, and peaceful male aggregations, have not previously been observed in spiders. Although direct behavioral observations are preliminary, we speculate based on the available evidence that these colonies may represent a novel and first case of lekking in spiders.”
Since it was near the end of the field season, the researchers had no opportunity for more observations, and never witnessed mating.
Other co-authors of the paper are Zachary Babbitz of Boston College, Matjaž Gregoric of the Slovenian Academy of Sciences and Arts, Onjaherizo Christian Raberahona of the University of Madagascar; Steven Williams, Oxford Brookes University, UK, and Matjaž Kuntner of the Smithsonian Institution.
Starrett, who joined the Bond lab in 2018, holds a doctorate in genetics, genomics and bioinformatics from UC Riverside. He is a former postdoctoral fellow (2016-2018) in the Jason Bond lab at Auburn University. Professor Bond joined the UC Davis faculty in 2018 from Auburn University, where he directed its Museum of Natural History (2011–2016), and served as professor and chair of the Auburn Department of Biological Sciences (2016–2018).
It's a myth. There are no established populations of Loxoceles reclusa in California, doctoral candidates Emma Jochim and Xavier Zahnle of the Jason Bond arachnology lab related during their 30-minute mythbusting at the Bohart Museum of Entomology open house, "Many Legged-Wonders," on Saturday, March 18. First-year doctoral student Iris Quayle of the Bond lab moderated the session.
They study with their major professor Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and associate dean, College of Agricultural and Environmental Sciences.
Jochim related that a person claiming to have been bitten by a brow recluse spider in California may have recently returned from a state where they are established or that they handled one that was shipped from that area.
That brings to mind the research of Rick Vetter of UC Riverside and his piece on "Myth of the Brown Recluse: Fact, Fear and Loathing."
"This website presents evidence for the lack of brown recluse spiders as part of the Californian spider fauna. Unfortunately, this contradicts what most Californians believe; beliefs that are born out of media-driven hyperbole and erroneous, anxiety-filled public hearsay which is further compounded by medical misdiagnoses. Although people are free to disagree, this opinion has come about after more than two decades of constant research resulting in many publications in the scientific and medical literature."
Vitter goes on to say: "Spiders are one group of arthropods that are very well known by the common person yet are terribly misunderstood; because of the rare occasion of a deleterious venom incident, almost all spiders are lumped into the category of 'squish first and ask questions later.' There are remarkably few spiders in California that are capable of causing injuries via biting. Overall, spiders are beneficial to humans in that they eat many pestiferous insects that either infest our foods (many phytophagous insects), are vectors of disease (flies, mosquitoes) or are aesthetically-challenged (cockroaches, earwigs). Unfortunately, humans have a low tolerance for spiders in their homes, either because spiders are symbols of danger, unkemptness or arachnophobia. One of the first steps one should take in dealing with these critters should be to identify them properly before blasting them with pesticide and/or getting hysterical."
Meanwhile, listen to UC Davis arachnologists:
Said one attendee: "Dr. Rick Vetter at U. C. Riverside fought the battle for the truth for decades and finally pretty much threw up his hands in defeat. He just couldn't get the media or California medical profession to stop claiming the Brown Recluse is HERE and diagnosing every little spot or open sore as a spider bite. My opinion is that people LIKE to think they were bitten by a brown recluse and wear it as a badge of honor. So much more thrilling than saying bacteria infection.”
It featured primarily spiders.
Next week the Bohart Museum is adding more legs. It's hosting an open house themed "Many-Legged Wonders."
The event, free and open to the public, is set from 1 to 4 p.m. Saturday, March 18 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus.
You can expect to see spiders, millipedes, centipedes, scorpions, tarantulas and isopods. And more.
Tabatha Yang, education and outreach coordinator for the Bohart announced that doctoral candidates Emma Jochim and Xavier Zahnle of the Jason Bond arachnology lab will dispel myths about spiders and millipedes at a question-and-answer session from 1 to 1:30. Doctoral student Iris Quayle will moderate.
From 1:30 to 4 p.m., will be the general open house with a showing of live animals and specimens. UC Davis student Elijah Shih will display his isopods. A family arts-and-crafts activity is also planned.
Research associate Brittany Kohler, the "zookeeper" of the Bohart petting zoo, says the current residents include:
- Princess Herbert, a Brazilian salmon-pink bird-eating tarantula (Lasiodora parahybana), age estimated to be around 20 (current oldest resident)
- Peaches, a Chilean rose hair tarantula (Grammostola rosea)
- Coco McFluffin, a Chaco golden knee tarantula (Grammostola pulchripes)
Beatrice, a Vietnamese centipede (Scolopendra subspinipes), newest resident
- Two black widows (Latrodectus hesperus)
- One brown widow (Latrodectus geometricus)
Among the other residents are Madagascar hissing cockroaches, a giant cave cockroach, stick insects, a bark scorpion and ironclad beetles.
The Bohart Museum, directed by UC Davis distinguished professor Lynn Kimsey, houses a global collection of eight million insect specimens, plus the petting zoo and a gift shop stocked with insect-themed books, posters, jewelry, t-shirts, hoodies and more. Dedicated to "understanding, documenting and communicating terrestrial arthropod diversity," the Bohart Museum was founded in 1946 and named for UC Davis professor and noted entomologist Richard Bohart. The insect museum is open to the public Mondays through Thursdays, from 8 a.m. to noon, and 1 to 5 p.m.
The science-based event, free and open to the public, is set for 11 a.m. to 3 p.m., Sunday, March 6 in the UC Davis Conference Center, 555 Alumni Lane.
This year the Biodiversity Museum Day is geared toward the UC Davis community, particularly undergraduates, said Biodiversity Museum Day co-organizer Tabatha Yang, education and public outreach coordinator for the Bohart Museum of Entomology. Admission and parking are free, but visitors must adhere to the COVID-19 Campus Ready guidelines. Masks will be required in accordance with campus policies. (See news story)
Sharing the Bohart Museum booth in the Conference Center will be the Jason Bond laboratory. Bond is the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and associate dean, College of Agricultural and Environmental Sciences.
"The arachnid/myriapod section of Biodiversity Museum Day will consist of some live specimens--a tarantula, trapdoor spider, scorpion, and some millipedes, and ethanol preserved specimens of arachnids/myriapods that are pretty common and/or well-known, and a small interactive station where people will be able to use props that mimic an insect flying into a web and learn more about the sensory structures that spiders have to detect those vibration," said doctoral candidate Lacie Newton of the Bond lab, coordinator of the exhibit.
Visitors to the Conference Center will see displays from 11 museums or collections on campus:
- Arboretum and Public Garden
- UC Davis Bee Haven
- Bohart Museum of Entomology
- Botanical Conservatory
- California Raptor Center
- Center for Plant Diversity
- Department of Anthropology Museum
- Museum of Wildlife and Fish Biology
- Nematode Collection
- Paleontology Collection
- Phaff Yeast Culture Collection
Visitors can sign up at the Conference Center for special tours:
- The Bohart Museum of Entomology, located in Room 1124 of the Academic Surge Building, Crocker Lane, has scheduled tours at noon, 1 and 2. The Bohart houses a global collection of eight million insect specimens, and also a live "petting zoo" and gift shop. "People will sign up at the Convention Center and be chaperoned over approximately 15 minutes before the hour to the attend their tour," said Tabatha Yang, education and outreach coordinator. "Tours should last 30 to 45 minutes." Entomologist Jeff Smith, curator of the Lepidoptera collection, will be discussing butterflies and moths.
- The UC Davis Bee Haven, located on Bee Biology Road, next to the Harry H.Laidlaw Jr. Honey Bee Research Facility, west of the central campus, will offer tours at noon and 2. Established in the fall of 2009, the Bee Haven is a half-acre demonstration garden operated by the Department of Entomology and Nematology. "We'll focus on how best to observe and identify bees in the garden, as well as suggested bee plants that grow well in our area with low water," said Christine Casey, academic program management officer of the Bee Haven.
- The Arboretum and Public Garden will provide two 30-45 minute tours, "Climate-Ready Tree Project: Texas Tree Trials." Groups will leave the Conference Center at 11:30 a.m. and 1:30 p.m. The project mission is to see if trees from west and central Texas will do well in this climate. The project involved collecting seeds, propagating them and planting them in the Arboretum.
- The Phaff Yeast Culture Collection is planning self-guided tours of the UC Davis Brewery, used for teaching and research, according to Kyria Boundy-Mills, curator, Phaff Yeast Culture Collection, Food Science and Technology.
Different yeast strains are used for different styles of beer. These include ale yeast strains, lager yeast strains, and Belgian beer strains that are hybrids of wild yeasts. UC Davis offers an undergraduate major in food science and technology, with an emphasis on brewing science. Training includes chemistry, biochemistry, microbiology, quality assurance, engineering, sanitation, packaging, malting and crewing. The program currently includes 18 students studying for their bachelor of science degrees, and three students seeking their master of science degrees.
- The Botanical Conservatory is technically not offering tours, says manager Ernesto Sandoval "but we will be open to the public so people can wander through at their own pace and we'll regulate the number of people in the greenhouse at any one time. They can see our revamped succulent and carnivore rooms as well as our Cacao, aka 'Chocolate Tree,' with fruits as well as coffee and a very happy vanilla plant all amongst an incredible diversity of plants from ferns to an assortment of orchids."
The UC Davis Biodiversity Museum Day is traditionally held on the Saturday of Presidents' Day weekend. However, last year's event was virtual, and this year's event is centrally located. For more information, access the UC Davis Biodiversity Museum Day website and/or connect with Instagram,Twitter, and Facebook.
Another upcoming event is the 108th annual UC Davis Picnic Day, a campuswide open house scheduled April 23./span>