- Author: Kathy Keatley Garvey
Some 145 people visited the UC Davis Bohart Museum of Entomology's open house last Saturday night between 8 and 11 in celebration of National Moth Week. Most stayed for the entire time, said Tabatha Yang, education and outreach coordinator.
Bohart Museum associate Greg Kareofelas and senior museum scientist Steve Heydon set up a blacklighting display: a white sheet and a mercury vapor lighting to attract moths and other flying insects.
“We recorded more than 15 species,” said Kareofelas, who has collected moths in his backyard in Davis for some 25 years. The first moth to arrive was the alfalfa looper moth, Trichopusia ni, and “the most striking,” he said, “was the grape leaffolder, Desmia funeralis.”
Inside the museum, located in Room 1124 of the Academic Surge Building on Crocker Lane, moths and butterflies took center stage. Visitors expressed amazement at the sizes and colors. Bohart associate Jeff Smith of Sacramento, who curates the butterfly and moth specimens, showed the worldwide collection and fielded questions.
Bohart associates and UC Davis students Lohitashwa Garikipati and Emma Cluff, UC Davis students, showed the museum's live petting zoo, which includes Madagascar hissing cockroaches, walking sticks, praying mantids and walking sticks.
The Bohart visitors gazed at the photo of President Trump and remarked how tiny the moth is. The wingspan of the orange-yellow moth is less than one centimeter.
Nazari published the piece on the Trump moth Jan. 17, 2016 in the journal Zookeys and explained the name: “The reason for this choice of names is to bring wider public attention to the need to continue protecting fragile habitats in the U.S. that still contain many undescribed species."
Three Trump moths were collected in a Malaise trap in one of the washes on the east side of the dunes. In a contract with the U.S. Bureau of Land Management, the Bohart scientists have collected nearly 2,000 species of insects from about 200 square miles of sand, according to Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis. Some six percent are new to science.
Of the Trump moths collected, Nazari kept one in Canada, the norm--but the holotype, the one he determined as the standard for the species--is a permanent part of the Bohart, said Tabatha Yang, education and outreach coordinator.
The Neopalpa donaldtrumpi belongs to the family, Gelechiidae of the Lepitoptera order.
The next summer open house, also free and open to the public, is Sunday, Aug. 27 from 1 to 4 p.m. the theme is “Bark Beetles and Trees, Forest Health in California." The event is in collaboration with Steve Seybold, USDA Forest Service entomologist and an associate of the UC Davis Department of Entomology and Nematology. He and his students and staff will be there to show displays and answer questions.
The Bohart Museum, directed by Lynn Kimsey, professor of entomology at UC Davis, houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.
The museum's gift shop, open year around, includes T-shirts, sweatshirts, books, jewelry, posters, insect-collecting equipment and insect-themed candy.
The Bohart Museum's regular hours are from 9 a.m. to noon and 1 to 5 p.m. Mondays through Thursdays. The museum is closed to the public on Fridays, Saturdays and Sundays and on major holidays. Admission is free.
More information on the Bohart Museum is available on the website or by contacting (530) 752-0493 or email bmuseum@ucdavis.edu.
- Author: Kathy Keatley Garvey
Hishinuma, who is completing her doctorate, studies the walnut twig beetle, Pityophthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease (TCD) of walnut and butternut trees.
Hishinuma works with major professor Mary Louise Flint and is co-advised by chemical ecologist and forest entomologist Steve Seybold of the Pacific Southwest Research Station, USDA Forest Service, Davis, an affiliate of the department. Flint is an Extension specialist emeritus with the UC Davis Department of Entomology and Nematology and a former associate director with the UC Integrated Pest Management Program.
“USDA will provide some financial support during the end stages of her Ph.D. thesis, in exchange for 320-640 hours of work and training over the next 14 months,” said Seybold. Then, in June 2016 her position will be converted to that of a permanent entomologist with the USDA Forest Service office in San Bernardino after she has completed her thesis. She will be responsible for forest insect survey, detection, and management on four national forests in southern California ranging from San Diego to Monterey counties.
“The highly competitive internship and guaranteed position are a credit to her and her achievements,” Seybold said.
Seybold and Flint assisted her in developing the internship, as did Richard “Rick” Bostock, UC Davis professor of plant pathology.
Hishinuma won the 2013 Western Forest Insect Work Conference Memorial Scholarship for her research on TCD and presented her work at group's 65th annual conference, held March 31-April 3, 2014 in Sacramento. She also received two scholarships from the California Garden Clubs, Inc. (CGCI) and a McBeth Memorial Scholarship to support her research on TCD.
The walnut twig beetle is believed to be native to Arizona, California, New Mexico and Mexico. In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen in declining black walnut trees in central Colorado. The disease has now spread east of the Mississippi to states in the heart of the valuable black walnut timberlands. Most recently it was reported from Indiana. Latest collection records show that the beetle and pathogen are now known from nine states in the western United States and seven states in the eastern USA. In 2013 the disease was also reported in Italy marking the first time that it occurred in Europe.
Seybold's research group has led the effort to characterize the disease in California and to develop a nationwide detection program for the beetle. They recently published two papers in the journal PLOS ONE that characterize the genetic diversity and invasion patterns of both the pathogenic fungus and the beetle in the United States. Scientists believe that TCD occurs only on walnut, butternut, and wingnut, but it is most damaging to native black walnuts, Juglans californica, J. hindsii, and J. nigra although the disease has been recorded on at least 10 species of walnuts or their hybrids in California. Often the first symptoms of TCD are flagging and yellowing leaves and branch dieback, Seybold said. Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus.
- Author: Kathy Keatley Garvey
Yigen Chen and Steve Seybold continually trapped the reddish-brown insect, about a third of the size of a grain of rice, for three years along Putah Creek in Davis, Calif., and recorded its daily and seasonal flight behavior. They lured the insect into the traps with a synthetic version of its aggregation pheromone.
“We discovered the collective and interactive effects of four environmental factors on the crepuscular (twilight) flight behavior of the insect,” said lead author Chen, a research entomologist and project scientist with the UC Davis Department of Entomology and Nematology. “We found that the optimal trapping conditions are a combination of moderate to warm temperatures, around 79 to 81 Fahrenheit; low light intensity; low wind speed, 0.6 to 2.5 miles per hour; and moderate barometric pressure, 755 to 757.”
“Understanding the walnut twig beetle's seasonal flight cycle and factors that govern its flight are critical first steps in the early detection of invasive species prior to implementing pest eradication or integrated pest management (IPM) programs,” they wrote in their research article, “Crepuscular Flight Activity of an Invasive Insect Governed by Interacting Abiotic Factors,”published in the Aug. 26 edition of the Public Library of Science, PLOS ONE.
However, when coupled with a hitchhiking fungus, Geosmithia morbida, it causes what is known as thousand cankers disease. The beetles create numerous galleries beneath the bark, resulting in fungal infection and canker formation. The large numbers of cankers led to the name, thousand cankers disease.
As the disease advances, the health of the tree declines and eventually it dies, sometimes within a three-year period, said Seybold, who has been studying the beetle and the newly discovered fungus with its barrel-shaped spores since 2008.
When male beetles initiate new galleries, they produce an aggregation pheromone. As the population increases, the flight response of males and females similarly increases.
Mating disruption or interruption of insect aggregation is crucial to controlling such insect pests as the walnut twig beetle in IPM programs, the entomologists pointed out. “Understanding the interactions among abiotic environmental factors on flight activity, should increase the efficacy of these methods in a specific IPM program to control the beetle,” Chen said.
“The primarily crepuscular flight activity had a Gaussian relationship with ambient temperature and barometric pressure but a negative exponential relationship with increasing light intensity and wind speed,” they wrote in their abstract. “A model selection procedure indicated that the four abiotic factors collectively and interactively governed P. juglandis diurnal flight.”
New knowledge of the primary periods of seasonal flight (May‒July and September‒October) “provides some guidance for when semiochemical-based interruption of aggregation may be applied most efficaciously,” they said..
Seybold, one of the first scientists to study the beetle and fungus in California, served on a scientific team that developed guidelines and trapping methods for the beetle. In 2010 and 2011, the team discovered and later patented the aggregation pheromone for the beetle and conducted scientific trials in northern California.
Late in the summer of 2011, the team demonstrated the efficacy of the pheromone as a flight trap bait. The bait lures both male and female beetles into a small plastic funnel trap.
The walnut twig beetle, native to the southwestern United States and Mexico, and widely distributed in Colorado, Arizona, California, and New Mexico, has now been detected throughout much of the United States: in nine western and five eastern states. In 2013, it was reported in northern Italy.
The earliest symptom of thousand cankers disease is yellowing foliage that progresses rapidly to brown wilted foliage, then finally branch mortality. Branch mortality and decline of the tree crown are one of three major symptoms of thousand cankers disease. The others are numerous small cankers on branches and the trunk, and holes and other evidence of tiny bark beetles.
Related links:
- Thousand Cankers Disease and the Walnut Twig Beetle in California (UC IPM)
- Walnut Twig Beetle (USDA Forest Service)
- Pest Alert, Walnut Twig Beetle and Thousand Cankers Disease (Colorado State University)
- Thousandcankers.com (This site is a collaborative effort between the Northeastern Area State and Private Forestry, the USDA Forest Service Northern Research Station, the Purdue University Department of Forestry and Natural Resources, the Hardwood Tree Improvement and Regeneration Center, the American Walnut Manufacturers Association, and the Walnut Council.)
- Author: Kathy Keatley Garvey
Hishinuma, who is seeking her doctorate, studies the walnut twig beetle, Pityophthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease (TCD) of walnut and butternut trees.
Hishinuma works with major professor Mary Louise Flint and is co-advised by chemical ecologist and forest entomologist Steve Seybold of the Pacific Southwest Research Station, USDA Forest Service, Davis, an affiliate of the department. Flint serves as an Extension specialist with the UC Davis Department of Entomology and Nematology and as the associate director for urban and community IPM, UC Integrated Pest Management Program. Both Flint and Seybold plan to attend the conference.
Previous recipients of the annual award have gone on to develop professional careers in forest entomology in academia or with the USDA Forest Service. UC Davis postdoctoral researcher Andrew Graves of Plant Pathology won the award in 2005 while a student at the University of Minnesota.
WFIWC is the core organization for forest entomologists in western North America with membership not only in the United States, but also in Canada and Mexico. The organization was founded in 1949 to provide an informal opportunity for forest entomologists to exchange new ideas and findings prior to each upcoming field season. It established the Memorial Scholarship Fund in 1990 to memorialize member Mark McGregor of the USDA Forest Service and later PheroTech Inc., who died in Idaho while working on research. Other contributions have since honored additional colleagues.
Hishinuma also received two scholarships from the California Garden Clubs, Inc. (CGCI) and a McBeth Memorial Scholarship to support her research on TCD.
The walnut twig beetle is believed to be native to Arizona, California, New Mexico and Mexico. In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen in declining black walnut trees in central Colorado. The disease has now spread east of the Mississippi to at least five states in the heart of the valuable black walnut timberlands. Latest statistics show that the beetle and pathogen are now known from nine states in the western U.S. and four states in the eastern U.S. There is a fifth state (Maryland) where only the beetle has been found and a sixth state (North Carolina) where only the pathogen has been found.
Seybold's research group has led the effort to characterize the disease in California and to develop a nationwide detection program for the beetle. Scientists believe that TCD occurs only on walnut, butternut, and wingnut, but it is most damaging to native black walnuts, Juglans californica, J. hindsii, and J. nigra although the disease has been recorded on at least 10 species of walnuts or their hybrids in California. Often the first symptoms of TCD are flagging and yellowing leaves and branch dieback, Seybold said. Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus.
Related link:
UC IPM: Thousand Cankers Disease in California
USDA: Thousand Cankers Disease
- Author: Kathy Keatley Garvey
Seybold, an affiliate of the UC Davis Department of Entomology and Nematology, is a chemical ecologist with the U.S. Department of Agriculture Forest Service's Pacific Southwest Research Station in Davis.
The article, written by Dinsa Sachan, begins: “If you want to keep insects off your crops, you have a couple of options: Spray the plants with pesticides or confuse the bugs with pheromones. The latter—chemicals used by insects to communicate—are more environmentally friendly, but manufacturing them involves harmful chemicals. Now, scientists have devised a method that enables them to produce pheromones from plants themselves, a safer and potentially more economical approach.”
Seybold, who was not involved in the study, was asked to comment on the research and noted: “The work is a ‘breakthrough' and ‘a wave of the future.' It will change the way that commercial pheromone outfits do business and will significantly enhance the quality and potentially lower the cost of the products that they provide."
The research, led by Christer Löfstedt, a chemical ecologist at Lund University in Sweden, dealt with the genetic modification of plants to “make components components of pheromones produced by the bird cherry ermine moth (Yponomeuta evonymella) and the orchard ermine moth (Y. padella),” wrote Sachan. “In the wild, female moths emit these sex pheromones to attract male suitors."
The research, "A Plant Factory for Moth Pheromone Production," is published in Nature Communications. Abstract: Moths depend on pheromone communication for mate finding and synthetic pheromones are used for monitoring or disruption of pheromone communication in pest insects. Here we produce moth sex pheromone, using Nicotiana benthamiana as a plant factory, by transient expression of up to four genes coding for consecutive biosynthetic steps. We specifically produce multicomponent sex pheromones for two species. The fatty alcohol fractions from the genetically modified plants are acetylated to mimic the respective sex pheromones of the small ermine moths Yponomeuta evonymella and Y. padella. These mixtures are very efficient and specific for trapping of male moths, matching the activity of conventionally produced pheromones. Our long-term vision is to design tailor-made production of any moth pheromone component in genetically modified plants. Such semisynthetic preparation of sex pheromones is a novel and cost-effective way of producing moderate to large quantities of pheromones with high purity and a minimum of hazardous waste.