They're small, about 1 mm long or less, with characteristic fringed wings. They fly, but not well.

But thrips do pack a powerful punch. 

A major pest of many agricultural crops, including lettuce, they damage plants by (1) sucking their juices and (2) transmitting viruses.  

If you've been following the thrips damage in the lettuce production in the Salinas Valley, or want to know more about thrips, the UC Davis Department of Entomology and Nematology's virtual seminar on Wednesday, Jan. 20 should interest you.

Research entomologist Daniel Hasegawa of the Crop Improvement and Protection Research Unit, Agricultural Research Service, U. S. Department of Agriculture, will speak on "Landscape and Molecular Approaches for Managing Thrips and Thrips-Transmitted Viruses in the Salinas Valley" at the department's first seminar of the winter quarter.  

The hour-long virtual seminar, via Zoom, begins at 4:10 p.m., announced agricultural Extension specialist Ian Grettenberger, seminar coordinator. To access the seminar, fill out this Google form link at https://bit.ly/3oWYjnt. (Contact Grettenberger at imgrettenberger@ucdavis.edu.)

"In 2019-2020, lettuce production in the Salinas Valley of California was devastated by thrips-transmitted impatiens necrotic spot virus (INSV)," Hasegawa says in his abstract. "Due to the inherent challenges in managing thrips using conventional chemical tactics, and no direct means for managing the virus, there is a strong need for new management strategies."

This seminar, he says, will provide an overview of 

1. The challenges in managing thrips and INSV in lettuce production
2. What we've learned about the epidemiology of thrips and INSV, and
3. Opportunities to improve cultural practices and develop biotechnology tools, such as RNAi for managing thrips and INSV in the Salinas Valley.

Hasegawa joined the Salinas USDA-ARS team in May 2019 after serving as a postdoctoral research associate (molecular biology) for three years with the USDA-ARS in Charleston, S. C.  He specializes in vector entomology, molecular biology and biotechnlogy. "My lab uses a variety of techniques to understand insect vector-virus relationships that impact plant health and agriculture," he says on Linked In. "We use molecular, genetic, and epidemiological concepts to understand drivers of vector-borne transmission of pathogens and utilize genetic technologies (e.g. RNAi and CRISPR), to improve agriculture productivity and sustainability."

Hasegawa received his bachelor of science degree in biochemistry in 2007 from UC Riverside and his doctorate in biology from Clemson University in 2013. 

The mission of the Crop Improvement and Protection Research Unit is to improve germplasm of lettuce, spinach and melon, determine basic biology of viral, fungal and bacterial diseases affecting these crops, develop alternatives to methyl bromide as a soil fumigant for control of soilborne pests in strawberry and vegetables, reduce postharvest losses of lettuce, develop scientifically based organic crop production practices, and develop methods for control of weeds. (See more on the Pacific West Area website.)

"More than 90 percent of the lettuce sold in the United States is grown in California, and the majority of production from April through October occurs in the Salinas Valley, while production form November through March occurs in California's Imperial Valley," according to keepcaliforniafarming.org.

The UC Statewide Integrated Pest Management Program (UC IPM) says this about thrips: "Thrips, order Thysanoptera, are tiny, slender insects with fringed wings. They feed by puncturing the epidermal (outer) layer of host tissue and sucking out the cell contents, which results in stippling, discolored flecking, or silvering of the leaf surface. Thrips feeding is usually accompanied by black varnishlike flecks of frass (excrement). Pest species are plant feeders that discolor and scar leaf, flower, and fruit surfaces, and distort plant parts or vector plant pathogens. Many species of thrips feed on fungal spores and pollen and are often innocuous. However, pollen feeding on plants such as orchids and African violets can leave unsightly pollen deposits and may reduce flower longevity. Certain thrips are beneficial predators that feed on other insects and mites."

"Thrips can readily move long distances floating with the wind or transported on infested plants, and exotic species are periodically introduced," UC IPM notes. 

Robbin Thorp would have been proud of what happened on Thursday, Jan. 14.

When the UC Davis emeritus professor of entomology, a global authority on bumble bees, died June 7, 2019 at age 85, scientists found a way to memorialize him and what he loved.

The Bohart Museum of Entomology--where Thorp spend much of his time identifying bees, helping scientists, and encouraging guests at open houses to learn about the wonderful world of bees--decided to memorialize him with an annual Robbin Thorp Memorial First-Bumble-Bee-of-the-Year Contest.  The first person to photograph a bumble bee in 2021 in the two-county area of Yolo and Solano would win.

And it is only fitting that Charlie Casey Nicholson, who studied bees with Thorp, won. He photographed a black-tailed bumble bee, Bombus melanopygus, in a manzanita patch  at 3:10 p.m., Thursday, Jan. 14 in the UC Davis Arboretum and Public Garden to claim the honor.  The site is near Old Davis Road.

Due to inclement weather, bumble bees are not easy to find this time of year. Neither are they easy to photograph.

In fact, Nicholson noted this was his seventh observation field trip to look for the first bumble bee of the year. He had searched six previous times (three 10-minute observations on the manzanita on each of two other days, Jan.  6 and 7).

As the winner, Nicholson will receive a special Bohart bumble bee coffee cup and a face mask, said contest coordinator Lynn Kimsey, director of the Bohart Museum and a UC Davis professor of entomology.  

Nicholson, a researcher in the UC Davis Department of Entomology and Nematology labs of Professor Neal Williams, a pollination ecologist, and Extension apiculturist Elina Lastro Niño, is a 2015 alumnus of The Bee Course, where Robbin Thorp, a UC Davis distinguished professor of entomology, taught from 2002 through 2018.  The nine-day intensive workshop, geared for conservation biologists and pollination ecologists and considered the world's premiere native bee biology and taxonomic course, takes place annually in Portal, Ariz., at the Southwestern Research Station, part of the American Museum of Natural History, N.Y.  

"It is truly an honor to win the contest," said Nicholson. "I was a student of Robbin's during the 17th annual Bee Course in Portal, Ariz. I will never forget him wielding his canopy net."  

"The first night (8/17/2015) he gave the opening seminar--a whirlwind tour of what makes a bee. It was so exciting to be at this research station surrounded by people whose names you've read all the time.”

“Robbin helped me learn to pay close attention to the arolia of Anthidiini. As we moved into identifying bees, Robbin was a great teacher as we worked through the dichotomous keys in The Bee Genera of North and Central America: Hymenoptera Apoidea. He always had some morphological signpost that wouldn't give away the 'answer' but would certainly guide you in the right direction." 

Charlie holds a bachelor of arts degree in biology (evolution, ecology and behavior), 2010, cum laude,  from Skidmore College, Saratoga Springs, New York. He received his doctorate in natural resources in 2018 from the University of Vermont, where he was a Gund Institute for Environment graduate fellow. In his dissertation, he examined how landscape and farm management affect the multiple benefits provided by wild bees. 

Nicholson joined UC Davis as a postdoctoral scholar in the spring of 2019, and receives funding support from the USDA Invasive Species and Pollinator Health Unit. He recently co-authored a paper, “Natural Hazard Threats to Pollinators and Pollination,” published in the journal Global Change Biology, that analyzed 117 published research papers on natural hazards that threaten pollinators and pollination. 

His other interests include multiple dimensions of biodiversity, conservation planning, agricultural management, ecosystem services, and community and landscape ecology. 

Robbin Thorp 
Thorp, a member of the UC Davis entomology faculty for 30 years, from 1964-1994, died June 7, 2019 at his Davis home at age 85. A tireless advocate of pollinator species protection and conservation, Thorp was known for his expertise, dedication and passion in protecting native pollinators, especially bumble bees, and for his teaching, research and public service. He was an authority on pollination ecology, ecology and systematics of honey bees, bumble bees, vernal pool bees, conservation of bees, native bees and crop pollination, and bees of urban gardens and agricultural landscapes.

He achieved emeritus status in 1994 but continued to engage in research, teaching and public service until a few weeks before his death. In 2014, he co-authored two books Bumble Bees of North America: An Identification Guide (Princeton University, 2014) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014).

Every summer from 2002 to 2018, Thorp volunteered his time and expertise to be one of the instructors in The Bee Course. In a 2013 interview with the UC Davis Department of Entomology and Nematology, Thorp said he loved teaching at The Bee Course and praised the co-instructors and students. "Ron McGinley who got his undergraduate degree at UC Davis does most of the initial student contact and scheduling for the course. Steve Buchmann, who got his PhD at UC Davis in 1978, is one of the instructors.  There are usually about eight instructors and 22 participants for the course.  Most of the time is spent in the lab identifying bees to genus.  At least three days are spent in the field so students can see various bees doing their thing, collect them and bring them back to the lab to identify them.  It is a great experience for students to interact with instructors and especially with their peers from around the world.  Instructors all donate their time to teach in the course, but benefit from the chance to get together with colleagues and a new cohort of interesting students each year.  Every class is different (that is, it takes on its own personality) and each student brings something new and different to the mix."

Robbin Thorp would have been proud of what happened on Thursday, Jan. 14.  

A reader asks: Does the UC Davis Bohart Museum of Entomology have a fact sheet on black widow spiders? 

Yes! It's among dozens of fact sheets (mostly insects but some arachnids and other non-insects) posted on the Bohart Museum website. All can be accessed and downloaded at no charge.

Lynn Kimsey, director of the Bohart Museum and a UC Davis professor of entomology, writes the fact sheets, including this one, titled "Widow Spiders."

"Widows are large, distinctive spiders in the genus Latrodectus," Kimsey writes. The Latrodectus mactans or black widow is found throughout the world in warmer regions, while the brown widow, L. geometricus, is found in warmer parts of the United States, including California.

You'll find widow spiders in and around homes, garages, barns and other human-made structures in California. "They build a tough, messy-looking three dimensional web in or behind objects in secluded and protected locations," Kimsey relates.

"During the summer months they may also commonly be found outside under shrubs, and other garden plants, or near porch lights," she says. "These spiders are excellent at controlling insects, particularly flies and crickets. They do not particularly like feeding on cockroaches, but will do so when other insects are unavailable."

What most folks seem to want to know about them are the bites. How painful and toxic are they?

"All spiders have painful and sometimes dangerous neurotoxic bites, but often give dry bites, with no venom," Kimsey points out. "In fact these are the only spiders in the United States with neurotoxic venom. The bites cause extreme physical discomfort and illness for several days to a week and can only be treated symptomatically. Common symptoms include pain in the vicinity of the bite, muscle aches, severe abdominal pain, vomiting, muscular cramping, sweating, fever and head- ache. The bite location itself may go unnoticed."

"There is usually no swelling at the site of the bite, where a small necrotic lesion may form, which heals slowly over a period of weeks or months. Black widow bites are rarely life threatening but may be dangerous for small children or individuals with chronic health problems. There have been no deaths from the bite of this spider for decades. Black widow bites can be dangerous for pets and can be fatal to small dogs or cats."

Kimsey advises that control is not necessary "unless a black widow is in an area frequented by people, particularly children, or by pets. It is important to remember that these are very shy spiders and never bite unless physically threatened."

Noted spider authority Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology and his lab usually present a program at the Bohart Museum on spiders at least once a year or engage with folks at the open houses. 

The Bohart Museum of Entomology, located in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis campus, is the home of nearly 8 million insect specimens, plus a live "petting zoo" (Madagascar hissing cockroaches, walking sticks and tarantulas) and a gift shop. The Bohart is temporarily closed due to the COVID-19 pandemic but the online gift shop is open, where you can find insect-themed t-shirts, hoodies, jewelry, posters, books, pens, and stuffed animal toys, as well as insect-collecting equipment.

Seen any bumble bees lately in Yolo or Solano counties?

If so, and if you photograph the first one of the year, you might win the Bohart Museum of Entomology's contest.

In memory of native pollinator specialist Robbin Thorp (1933-2019), UC Davis distinguished emeritus professor of entomology, the Bohart Museum is sponsoring the inaugural Robbin Thorp Memorial First-Bumble-Bee-of-the-Year Contest.

Professor Thorp, 85, who died June 7, 2019, was a global authority on bumble bees, and always looked forward to seeing the first bumble bee of the year.  He launched an impromptu contest several years ago with a small group of bumble bee enthusiasts/photographers from Yolo and Solano counties.  

Now the Bohart Museum, where Thorp spent much of his time identifying bees and helping others, is sponsoring the contest. Participants are to capture an image of a bumble bee in the wild in either Yolo or Solano counties and email the image to bmuseum@ucdavis.edu, with the details of time, date and place. The image must be recognizable as a bumble bee.  The winner receives bragging rights and a special gift from the Bohart Museum, said Lynn Kimsey, director of the Bohart and UC Davis professor of entomology. Plans call for a Bohart coffee mug with a bumble bee image.

The first bumble bee to emerge in this area is the black-tailed bumble bee, Bombus melanopygus. Native to western North America and found from California to British Columbia and as far east as Idaho, it forages on manzanitas, wild lilacs, wild buckwheats, lupines, penstemons, clovers, and sages, among others.

Thorp, a 30-year member of the UC Davis entomology faculty, from 1964-1994, co-authored two books, Bumble Bees of North America: An Identification Guide (Princeton University, 2014) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014). He achieved emeritus status in 1994 but continued to engage in research, teaching and public service until a few weeks before his death.

A tireless advocate of pollinator species protection and conservation, he was known for his expertise, dedication and passion in protecting native pollinators, especially bumble bees, and for his teaching, research and public service. He was an authority on pollination ecology, ecology and systematics of honey bees, bumble bees, vernal pool bees, conservation of bees, native bees and crop pollination, and bees of urban gardens and agricultural landscapes.

Thorp co-taught The Bee Course from 2002 to 2019, an intensive nine-day workshop affiliated with the American Museum of Natural History and held annually at the Southwestern Research Station, Portal, Ariz.

Kimsey, who first met Thorp when she was a graduate student at UC Davis, said that although he wasn't her major professor, “my project was on bees and he was incredibly helpful and supportive. His enthusiasm about pollinators and bees in particular actually grew after he retired, and he continued helping students and researchers and was the backbone of so much research. His support and kindness was matched by his undemanding assistance and expertise. What a terrible loss to his family and to the research and conservation communities." 

An authority on the critically imperiled Franklin's bumble bee, Bombus franklini,  Thorp began monitoring the bumble bee population in 1998 in its narrow distribution range of southern Oregon and northern California. He had not seen it since 2006 and was instrumental in placing Franklin's bumble bee on the Red List of Threatened Species of the International Union for Conservation of Nature and Natural Resources (IUCN). Long active in the North America IUCN Bumblebee Specialist Group, Thorp served as its regional co-chair, beginning in 2011. 

In August of 2016 a documentary crew from CNN, headed by John Sutter, followed Thorp to a meadow where he last saw Franklin's bumble bee. Sutter wrote about Dr. Thorp, then 82, in a piece he titled "The Old Man and the Bee," aspinoff of Ernest Hemingway's "The Old Man and the Sea." (See "Will Franklin's Bumble Bee Ever Be Seen Again?"on YouTube by EarthFixMedia.)

Highly honored by his peers, Thorp was named a fellow of the California Academy of Sciences, San Francisco in 1986; recipient of the Edward A. Dickson Emeriti Professorship of UC Davis in 2010; and recipient of the UC Davis Distinguished Emeritus Award in 2015. Other honors included: member of the UC Davis Bee Team that won the Team Award from the Pacific Branch, Entomological Society of America (PBESA) in 2013. In addition, he was a past president (2010-2011) of the Davis Botanical Society, and former chair (1992-2011) of the Advisory Committee for the Jepson Prairie Reserve, UC Davis/Natural Reserve System. 

UC Davis professor and pollination ecologist Neal Williams, who organized a special symposium in Thorp's honor at the 2019 PBESA meeting in San Diego, praised his “tireless efforts in research, advocacy and education” and how he “inspired a new generation of bee researchers.”