"In 2020, malaria deaths increased by 12 percent compared with 2019. The increases in malaria cases are deaths were associated with disruption to services during the COVID-19 pandemic. Malaria burden was heaviest in the WHO African Region, with an estimated 95 percent of cases and 96 percent of deaths; 80 percent of all deaths in this region are among children aged under 5 years."--World Health Organization

Enter Filipa Rijo-Ferreira, a UC Berkeley School of Public Health (BPH) assistant professor who specializes in parasitology and circadian rhythms.

She'll present a UC Davis Department of Entomology and Nematology seminar at 4:10 p.m., Wednesday, Oct. 19 on "Circadian Rhythms in Parasitic Diseases" in 122 Briggs Hall. Her seminar also will be virtual. The Zoom link is https://ucdavis.zoom.us/j/95882849672. Host is molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology.

"Malaria's main symptom is the periodic fevers experienced by patients, fevers that ‘come and go' at certain times of the day and are a consequence of synchronized parasite rhythms," Rijo-Ferreira says in her abstract. "In humans, circadian clocks regulate multiple aspects of physiology, including sleep-wake cycles, metabolism, and immune defense. Circadian biology leads to body rhythms experienced by the pathogens that infect humans. In addition to sensing host rhythms, we recently discovered that parasites which cause devastating health burdens such as malaria and sleeping sickness diseases also have their own intrinsic clocks. The clocks of parasites regulate core biological functions from metabolism to the cell cycle, and the discovery of the existence of their clocks serves as an opportunity to access the molecular mechanisms regulating their rhythmic biology."

A native of Lisbon, Portugal, Rijo-Ferreira joined the UC Berkeley Public Health faculty in January 2022. She describes herself as a "scientist passionate about the complex daily host-parasite interactions and how parasites evolved circadian clocks to anticipate environmental cycles." She recently authored "The Malaria Parasite Has an Intrinsic Clock," published in Science magazine.

Trained in infectious diseases and neuroscience, Rijo-Ferreira holds a bachelor's degree in molecular and cellular biology from Nova University of Lisbon, and her master's degree in 2009 in molecular genetics and biomedicine from Imperial College, London. She received her doctorate in 2016 at the University of Porto, Portugal, where she completed her studies in basic and applied biology, molecular parasitology, and neuroscience. Postdoctoral training followed at the University of Texas Southwestern Medical Center, Dallas where she won the Brown-Goldstein Award for Excellence in Postdoctoral Research in 2021 for her work investigating the circadian clocks of human parasites. She studied with world-renowned circadian rhythm researcher Joseph Takahashi, professor and chair of the Department of Neuroscience and an investigator with the Howard Hughes Medical Institute, UT Southwestern Medical Center.

"Our lab is interested in parasitic infections and we study them under the lenses of time of day," Rijo-Ferreira wrote on her lab website. "Our rhythmic world has been a driving force for organisms to evolve a molecular clock to anticipate such daily rhythms. Similarly, our own circadian biology leads to physiological rhythms that parasites experience.We study the single-celled parasites Plasmodium spp. that causes malaria, and Trypanosoma brucei that causes sleeping sickness. We employ technical approaches spanning from next-generation sequencing, to cellular and behavioral assays to investigate the interactions of these parasites with their hosts.Our work seeks to understand how circadian rhythms modulate host-parasite-vector interactions and identify opportunities in their rhythmic biology to treat parasitic infections

In an interview with BPH staff writer Eliza Partika, published in February 2022, she commented: "I am fascinated about our day and night cycles and how organisms evolved to anticipate them. I find it incredible that parasites, such as the ones that cause malaria, show a coordinated rhythmic pattern themselves, which underlies periodic fevers in infected individuals. Our research is aimed at understanding how this phenomenon is regulated molecularly, and how we can disrupt these rhythmic patterns to offset the infection."

"At BPH, we aim to set up a framework where we can explore the relationships between parasites, hosts, and the mosquitoes that serve as the vector of disease transmission, based on the time of day," Rijo-Ferreira related. "We hypothesize that the circadian rhythms of these three organisms need to be aligned in order for the parasite to cause an efficient infection. In fact, when rhythms are misaligned, there is a reduction in parasite levels. Thus, identifying the molecular players from host, parasite, and mosquito is essential to understanding this phenomenon and creating alternative strategies to manage deadly infections like malaria and sleeping sickness."

Rijo-Ferreira said she seeks to "bring to the attention the circadian aspect of infectious diseases and bring awareness of the potential benefits of time of day vaccination and drug treatment."

Emily Meineke, assistant professor of urban landscape entomology, UC Davis Department of Entomology and Nematology, coordinates the department's seminars for the 2022-23 academic year. All 11 seminars will take place both person and virtually at 4:10 p.m. on Wednesdays in Room 122 of Briggs Hall except for the Nov. 9th and Dec. 7th seminars, which will be virtual only, she said.  (See list of seminars)

For further information on the seminars or to resolve any technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu. 

Clara Stuligross is passionate about wild bees, and you should be, too.

Stuligross, who received her doctorate in ecology on Sept. 9 from UC Davis, will present her exit seminar, "Individual and Combined Effects of Resource and Pesticide Stressors on Wild Bees and a Potential Strategy to Mitigate Impacts" at 10 a.m., Tuesday, Oct. 18 in Room 1022 of Green Hall. 

The seminar, open to all interested persons, also will be virtual. The Zoom link is https://ucdavis.zoom.us/j/3661107142.

Stuligross researches nutrition and pesticide exposure and their comparative effects on the blue orchard bee, Osmia lignaria, and the yellow-faced bumble bee, Bombus vosnesenskii. Pollination ecologist Neal Williams, professor in the Department of Entomology and Nematology, served as her major professor.

"I am doing a short postdoc with Neal Williams this fall, and in January I will start a postdoctoral research position with Nicole Rafferty at UC Riverside," Stuligross said.

"Anthropogenic environmental changes present multiple stressors that together impact biodiversity and ecosystem function," Stuligross writes in her abstract. "Among these, pesticide exposure and the loss of flowering plants are ubiquitous across contemporary landscapes and threaten the persistence of bee populations. In this dissertation, I explored the individual and combined effects of pesticide and floral resource stressors on bee behavior, reproduction, and population persistence, as well as a potential strategy for mitigating these impacts. I used a combination of manipulative field cage experiments and landscape studies to examine these stressors and their impacts at different scales.

"Because bees often experience pesticide and resource stressors simultaneously, I first examined the potential for interactive effects of these stressors, as well as their individual impacts on wild bees. I established a fully crossed design in field cages; nesting female Osmia lignaria, the solitary blue orchard bee, accessed wildflowers at high or low densities, treated with or without the common insecticide, imidacloprid. In Chapter 1, I showed that pesticide exposure and floral resource scarcity combined additively to dramatically alter multiple vital rates, including reduced reproduction and a male-biased offspring sex ratio. In Chapter 2, I quantified behavioral responses in the same experiment, revealing that the resource and pesticide stressors had differential impacts with consequences for bee populations and potentially for pollination services through individual behavioral changes. Limited floral resources required bees to make fewer, longer foraging trips as well as misidentify their nests more often upon return from these trips. Bees exposed to pesticides made shorter foraging trips and did not compensate for this by taking more trips, reducing their overall foraging activity. Pesticide exposure also interacted with age to affect antagonistic behavior."

"In Chapter 3, I examined the carryover effects of past pesticide exposure on wild bees. Using the offspring from the previous cage experiment with known pesticide exposure backgrounds, I re-established the field cages and released bees in a crossed design with pesticide exposure or no exposure in each year. Thus, some bees experienced pesticides over two generations and others not at all. Regardless of the past exposure history, pesticides in the second year reduced reproduction. For bees that were also exposed in the past, the exposure over two years additively impaired individual performance, leading to a nearly fourfold estimated reduction in bee population growth. Furthermore, even past exposure by itself, regardless of exposure in the second year, led to a decline in offspring production."

"In Chapter 4, I collaborated with Maj Rundlöf to investigate the potential for wildflower plantings to mitigate the negative effects of pesticide exposure in agricultural landscapes. We assessed the nesting and reproduction of O. lignaria and the bumble bee Bombus vosnesenskii in replicate agricultural landscapes, half of which contained a wildflower planting next to the nest or colony. We collected pollen from foraging bees to determine resource use and pesticide residues. The wildflower plantings were a source of pesticide exposure, especially for O. lignaria, but also supported O. lignaria nesting. The landscape-level floral resources better predicted B. vosnesenskii colony success, but the local flower resources mitigated the negative effects of pesticides on their reproduction."

"These chapters together show that two common environmental stressors combine to negativel impact bees. They also reveal potential mechanisms underlying impacts of the stressors on reproduction and population growth. My dissertation highlights the importance of mitigating the negative effects of pesticides and floral resource limitation, especially in agricultural landscapes where the two stressors often co-occur. Finally, this work offers insight into how the stressors could be mitigated through an emerging strategy to diversity agricultural landscapes."

Stuligross received her bachelor of arts degree in environmental studies in 2014 in Indiana from Earlham College, Richmond, where she minored in biology and outdoor education. At UC Davis, she was awarded a 2017-22 National Science Foundation Graduate Research Fellowship, and a 2016-18 UC Davis Graduate Group in Ecology Fellowship.

Recognized nationally for her research, Stuligross scored second place in the Entomological Society of America's 2020 President's Prize competition. Her research posters also won the top award at the UC Davis Graduate Student Symposium in Ecology in both 2019 and 2021.  

Stuligross and her colleague, Maj Rundlöf, are the co-first authors of "Flower Plantings Support Wild Bee Reproduction and May Also Mitigate Pesticide Exposure Effects," published in May 2022 in the Journal of Applied Ecology. She was the lead author of "Past Insecticide Exposure Reduces Bee Reproduction and Population Growth Rate," published in November 2021 in the Proceedings of the National Academy of Sciences, and also the lead author of "Pesticide and Resource Stressors Sdditively Impair Wild Bee Reproduction," published in September 2020 in The Proceedings of the Royal Society B. 

Stuligross has also co-authored a number of other research publications, most recently:

• "A Meta-Analysis of Single Visit Pollination Effectiveness Comparing Honeybees and Other Floral Visitors," American Journal of Botany
• "Impact of 'Nonlethal' Tarsal Clipping on Bumble Bees (Bombus vosnesenskii) May Depend on Queen Stage and Worker Size," Journal of Insect Conservation

Want to learn more about wild bees, also known as undomesticated bees? Be sure to read the UC-authored book, California Bees and Blooms: A Guide for Gardeners and Naturalists. It's the work of Gordon Frankie of UC Berkeley, the late Robbin Thorp of the UC Davis Department of Entomology and Nematology; Barbara Ertter of UC Berkeley; and photographer Rollin Coville, alumnus of UC Berkeley. California is home to more than 1600 species of undomesticated or wild bees. 

'Tis "Friday Fly Day" (also known as #Fridayflyday in the Twitter world), and it's almost Halloween.

So why not combine the two with a common drone fly, Eristalis tenax, nectaring on a pumpkin-orange Mexican sunflower, Tithonia rotundifola?

To the untrained eye, the drone fly is often mistaken for a honey bee. Both, however, are pollinators.

But the larva of the drone fly is known as a rattailed maggot and feeds off bacteria in drainage ditches, manure or cess pools, sewers and the like. Unlike a honey bee, the drone fly has one set of wings, large eyes, stubby antennae, and a distinguishing "H" on its abdomen. 

The drone fly will still be hanging around when Halloween arrives, but how many costumes have you seen glorifying the drone fly? The honey bee, yes! But a drone fly? No.

 

Want to join the 2022-23 Seed Pile Project, a community science initiative by Miridae Living Labs of West Sacramento and UC Davis faculty that aims to better understand the dynamics of native plant seed dispersal in human-dominated landscapes? 

If you live in the Sacramento area (including Davis) and the East Bay, ecologist Billy Krimmel, a UC Davis doctoral alumnus and founder of Miridae Living Labs, invites you to participate.

1. You sign up here
2. You get 3 free packets of native wildflower seeds
3. You drop them somewhere in your neighborhood or commute
4. You DO NOT water or maintain them
5. You monitor them once a month until May using the Miridae app and "tell us what you see"

It works like this: "Community participants to drop small piles of local, California native seeds in urban areas where they live or work, then monitor the results through repeated observations," Krimmel said. "Using data from participants on the conditions under which certain species of these locally adapted seeds spread, survive, or die, we can gain a better understanding of which native species to incorporate into the built environment and where to put them for the greatest ecological benefit and resilience."

"The basic goal is to learn which species can thrive in human-occupied spaces, especially transportation corridors," said Krimmel, who received his doctorate in ecology in 2015, studying native plant-insect interactions with major professor Jay Rosenheim, distinguished professor of entomology.  "This year we are collaborating with UC Davis entomologists who will use these seed piles to learn about how certain urban conditions impact native bee species."

Miridae will be working with two UC Davis Department of Entomology and Nematology faculty, pollination ecologist Neal Williams, professor, and urban landscape entomologist Emily Meineke, assistant professor. Also on the team is assistant professor Haven Kiers of the Department of Human Ecology, who specializes in landscape architecture and environmental design. 

"We encourage folks of all ages to participate, and we provide resources such as seedling identification guides to help you identify the species in your seed piles," Krimmel said. "This is a great project for school classes and scout troops in addition to individuals."

The seed packets will contain Arroyo Lupine, California golden poppy, Phacelia ciliata, Bolander's sunflower, Madia elegans and Nemophila.

A kickoff gathering is set from 4 to 7 p.m., Thursday, Nov. 17 at the Jackrabbit Brewing in West Sacramento where participants can pick up their seed packets, meet other participants, and perhaps buy a native plant and/or beverage. "There will be other pickup options as well," he said. 

Krimmel founded the company, located at 1385 Terminal St., West Sacramento, with the intention of “creating habitat for native species within human-occupied areas and engaging people with the species interactions occurring in these habitations.” Its mission: "To strengthen connections between people, native plants, and wildlife through design, construction, outreach and research."

The name, Miridae, is Latin for a family of insects known as “plant bugs,” or mirids, which Krimmel researches. One of the most well-known mirid is the lygus bug, a serious pest of cotton, strawberries and alfalfa. 

Miridae won the highly competitive 2020 Award of Excellence for Communication from the American Society of Landscape Architects (ASLA) for its Seed Bank Living Wall at DPR Construction, Sacramento.   The ASLA awards, judged by a jury of professionals, honor the best in landscape architecture from around the globe.

Of his company, Krimmel says: “We create habitat for, and engage people with, native plants and the wildlife they support. We do this by tying together design, science, and high-quality construction to create landscapes that are beautiful, resilient, and ecologically powerful.”  His goal, with each project, is to “come one step closer to creating a network of habitat gardens and migration corridors to support resilient populations of native species.” 

Krimmel may be reached via his website www.miridae.com or on Instagram.