What's better than a yellow-faced bumble bee (Bombus vosnesenskii) on yellow mustard?

Not much. Both are signs of early spring.

Mustard is popping up all over, along with oxalyis and wild radish. The earth is warming. Spring is here. Get ready.

In the University of California book, California Bees and Blooms:  Guide for Gardeners and Naturalists, the authors write that B. vosnesenskii and B. melanopygus "are considered spring bees because that is when their population is highest, tailing off in numbers the rest of the year."

The book is the work of Gordon Frankie, UC Berkeley entomology professor; Robbin Thorp, distinguished emeritus professor of entomology at UC Davis;  photographer and entomologist Rollin Coville (he received his doctorate from UC Berkeley), and botanist Barbara Ertter, also affiliated with UC Berkeley.

Be sure to check out their companion pocket guide on the UC ANR website. It's titled Common Bees in California Gardens. It will help you identify 24 of the most common bees found in urban gardens and landscapes. That's 24 out of nearly 1600 species of native bees found in the Golden State.

 Yellow-faced bumble bee, yellow mustard, Golden State....Life is good...

Congratulations to Hoang Danh “Derrick” Nguyen, a graduate student in the Christian Nansen lab, UC Davis Department of Entomology and Nematology, for his recent publication in the journal Agronomy for Sustainable Development.

In his paper, titled “Edge-Biased Distributions of Insects: A Review,” Nguyen reviewed how many species of insects show a definite preference for living on the edges of fields and orchards.

This phenomenon can lead to more accurate monitoring and better pest management tactics, said Nguyen and co-author Nansen.

The paper indicates that “the prevalence of such edge-biased distributions has considerable implications for how to sample and monitor insects, and it also suggests that in many cases pest management tactics, such as, releases of natural enemies or insecticide applications can be spatially targeted to field edges.”

What's extremely noteworthy is that Nguyen, now studying for his master's degree, wrote the paper as an undergraduate student. “He decided to write a review article on a topic related to insect ecology and pest management,” said Nansen, an agricultural entomologist who specializes in applied insect ecology, integrated pest management (IPM) and remote sensing. "His main goals were to improve his scientific writing and to get familiar with the process of publishing scientific publications. The end result was an article about a very widespread—but poorly understood phenomenon—insects are often spatially aggregated along environmental edges.”

Nguyen traced the history of edge-based distribution of insects in agricultural systems to a study on black bean aphids led by British entomologist C. G. Johnson and published in 1950 in the Annual of Applied Biology. The aphids, major pests of sugar beet, bean and celery crops, spread from the field edges to within, but the edges remained the areas of highest aphid density.

Nguyen also called attention to scientific studies that found that wild bees in high bush blueberry were more prevalent along the edges of orchards, and that the density of the pest, Asian citrus psyllid, prevailed more at the edges of citrus groves than within.

Nansen praised Nguyen's work as outstanding. “Sometimes we professors are fortunate enough to interact with undergraduate students who – even with English not being their first language – possess keen abilities to describe a scientific problem or phenomenon in clearly articulated scientific writing, and Derrick is a great example of that!”

 “He started writing drafts of this review article about six months before he started as a graduate student,” Nansen said.  "This review article is an example of how we can use writing of review papers as a tool to engage with undergraduate students before they start their thesis projects.” Professor Jay Rosenheim of the UC Davis Department of Entomology and Nematology also helped with the drafts.

“We are supposed to focus more and more on ‘diversity' and here we have an undergraduate from Singapore publishing in a very prestigious journal,” Nansen added.

The UC Davis scientists suggest that mathematical modeling approaches can partially explain edge-biased distributions but “that abiotic factors, crop vegetation traits, and environmental parameters are factors that are likely responsible for this phenomenon.”

They advocate more research, especially experimental research, “to increase the current understanding of how and why edge-biased distributions of insects are so widespread.”

“In my opinion, discussions about edge-biased distribution of insects tend to be entomocentric; much emphasis is often put on the insects themselves,” Nguyen commented. “However, agricultural insect pests are dependent on their host plants for survival. Interestingly, it has been shown in various systems that agricultural crops also display edge effect as well. Therefore, through my review, I would like to bring attention to this correlation and propose insect-plant interactions as a potential explanation of edge effect and broaden the discussion about this widely observed but insufficiently understood phenomenon.”

Nguyen received a bachelor's degree in plant sciences from UC Davis in December 2017, graduating with highest honors. A high-achieving scholar, he was on the dean's honor list, College of Agricultural and Environmental Sciences, every quarter since the fall of 2015. He enrolled in the UC Davis graduate student program in entomology in January 2018.

“I am interested in IPM, insect behavior and insect ecology, and greenhouse production of leafy vegetables,” he said. “Currently I am working on projects that explore the potentials of hyperspectral imaging technology as early detection tools for pest infestation and insect host selection based on the framework of preference-performance hypothesis. As my research model, I focus on the interactions between vegetables (bok choy and spinach) and their insect pests (leafminers and armyworms).

Nguyen served as an assistant training officer with the Singapore Armed Forces (SAF) from April 2014 to March 2015. For his studies at UC Davis, he received a 2015-2019 undergraduate and graduate scholarship sponsored by Agri-Food and Veterinary Authority of Singapore.

“For my career plan, since I am currently sponsored by AVA, I will be working for them for six years upon my graduation,” Nguyen said. “In the long term, I am interested in doing a Ph.D in imaging technology for pest detection, plant health status analysis and food quality analysis.”

Well done.

Think spring. Think ceanothus. Think salvia. Think pollinators.

Despite the rain forecast, the open house and plant sale at the Häagen-Dazs Honey Bee Haven at the University of California, Davis, will take place from 11 a.m. to 2 p.m., Saturday, April 7.

The haven, a half-acre bee friendly garden operated by the UC Davis Department of Entomology and Nematology, will offer a number of plants, including asters, California fuchsia, salvia, ceanothus, manzanita, coffeeberry and currant.  Favorites include Salvia "Bee's Bliss" and Ceanothus "Valley Violet." Check out the plant list here. Payment is cash only.

Meanwhile, the plant sale initially scheduled Saturday, April 7  at the UC Davis Arboretum Nursery on Garrod Drive has been postponed until April 14. Hours: 9 a.m. to 1 p.m. The one-acre Arboretum Nursery will be offering Arboretum All-Stars, California natives and thousands of other attractive, low-water plants perfect for creating a landscape alive with environmentally important pollinators."   Look for the inventory here. Members receive discounts, and you can join online, at the gate. Credit cards are accepted.

Think spring. Think ceanothus. Think salvia. Think pollinators. 

Yes, you do eat insects!

Maybe not deliberately, as in those who engage in entomophagy, the technical term for eating insects. Think of chocolate chirp cookies! Think of cricket flour! Think of making a meal out of mealworms.

For thousands of years, "humans have harvested the eggs, larvae, pupae and adults of certain insect species from forests or other suitable habitats to eat," according to a page on the UC Riverside Center for Invasive Species Research website. "This practice is still common in many tropical countries where certain insect species grow to large sizes, and they are abundant and relatively easy to harvest year around. Insects as food are an excellent source of proteins, vitamins, fats, and essentail minerals."

In fact, as the UC Riverside officials point out: "there is a strong case in favor of mass rearing insects for food as this practice is probably less environmentally damaging than other forms of protein production." And, compared to eating cattle, eating insects is "five times more efficient at converting food into edible tissue."

Coming soon: insect farms in your community? Or in your cornmeal?

Last Monday, yours truly posted an article on "bugs in cornmeal" on the UC ANR Food Blog about an "insect farm" in the six-month-old cornmeal in our pantry. The cornmeal came to life in a see-through jar, with a tightly fitted lid, but you could barely see them.

Booklice. Nearly microscopic.

These Liposcelis bostrychophila, or "psocids" (pronounced "so kids"), are common pests in stored grains. They're usually unseen because they're about a millimeter long--about the size of a speck of dust--and are transparent to light brown in color.

They're called "booklice," although they are not lice. "Booklice can be scavengers and often feed on the bits of mold or fungi that grow on damp materials," entomologist Jeff Smith, who curates the Bohart Museum of Entomology's butterfly and moth collection, explained. "Very old, neglected food stuffs are also subject to them, and the key to prevention is to use food materials reasonably quickly and not store them for years, store them in a nice dry location and in airtight containers."

"They very well could have been in the food already when you bought it, but they're so common that you probably have some roaming around in the house all the time, just looking for something good to eat. They'll feed on dead bugs in window sills, stale pet foods, etc."

Statistics indicate that the average American unknowingly eats one to two pounds of insects a year.  But the U.S. Food and Drug Administration "has very specific tolerances for the amount of residue in food stuffs," said Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis.

Want to know what the action level is? Check out this FDA document.

Yes, you do eat insects!