Mark Hoddle

A plague of pests is coming for California. Here’s how to stop it.

tomwt — Wed, 02 Jul 2025 15:39:53 +0000

A plague of pests is coming for California. Here’s how to stop it. tomwt Wed, 07/02/2025 - 08:39 More CNAS in the Media Andrew Zaleski | The New York Times July 02, 2025

THE NEW YORK TIMES - Back in the late 1880s, California citrus farmers found themselves dealing with a crisis caused by a fat bug covered in a shieldlike, granular white wax. Known as the cottony cushion scale, this insect, which had hitchhiked aboard ships from Australia, usually spends its entire life with its mouth affixed to a single plant, greedily sucking out nutrients. Now the bugs were making meals of the state’s citrus trees.

Some farmers resorted to erecting large canvas tents around their trees and fumigating the inside with hydrogen cyanide in attempts to murder the insect, which proved ineffective. That’s when Charles Valentine Riley, who pioneered the field of entomology in the United States, was called in.

In his role as chief entomologist of the U.S. Department of Agriculture, Mr. Riley sent an assistant to the land down under in 1888 to hunt for the bugs’ natural predator. Within three months, a shipment of small branches arrived in California. The branches carried not only cottony cushion scale, but also another bug: the Vedalia beetle, a species of ladybug and a natural predator of the scale. As more shipments arrived, entomologists in California bred the beetles and eventually released them, marveling as the ladybugs dined ravenously. By the end of 1889, the fat cottony cushion scale was no longer a grave threat to citrus growers.

“It’s hard to imagine what California’s economy would have been like if citrus had collapsed and never taken off,” said Mark S. Hoddle, an entomologist at the University of California, Riverside.

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Department of Entomology

Mark Hoddle

The good, bad and ugly truths about LA tumbleweeds and their role in fires

tomwt — Mon, 27 Jan 2025 16:18:42 +0000

The good, bad and ugly truths about LA tumbleweeds and their role in fires tomwt Mon, 01/27/2025 - 08:18 More CNAS in the Media Fiona Ng | LAist.com January 26, 2025

LAIST.COM - It was Jan. 11 — the first Saturday after the two huge L.A. fires broke out.

The city was thick with haze and smoke; ash was twirling in the air, and somehow, despite it all, our myth-making sunset still shone through.

I was heading home to El Sereno that afternoon, made a turn, and slammed on the brakes.

Fifty to 100 tumbleweeds had parked themselves along Multnomah Street, extending to the hillside above.

...

Russian thistles, better known as tumbleweeds, arrived in South Dakota in the 1870s most likely via a shipment of flaxseeds from Russia that was contaminated with the invasive seeds.

"Then those tumbleweeds just spread across the western United States and they've found a great home here in California," said Mark Hoddle, an invasive species expert at UC Riverside.

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Mark Hoddle

Monitoring Argentine Ant populations

ilseu — Mon, 31 Aug 2020 21:43:17 +0000

Monitoring Argentine Ant populations ilseu Mon, 08/31/2020 - 14:43 More CNAS in the Media Tim Hammerich | California Ag Today August 26, 2020

CA AG TODAY - The Argentine Ant is a problem in citrus orchards and vineyards mostly because it protects sap-sucking pests from natural predators. Entomologist Dr. Mark Hoddle and his team at UC Riverside have created a tool to help farmers more effectively manage these ants based on the fact that the like to move on irrigation pipe.

Hoddle… “So what we have done is working with computer engineers here at UCR, we've developed infrared sensors. The sensors clip onto the irrigation pipe. And as the ants moved back and forth along this pipe, and each time they break the beam, the little computer chip in here records, number of ants that are moving along the pipe.”

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Department of Entomology

Mark Hoddle

Long-distance palm weevil flyers threaten California date palms

ilseu — Tue, 11 Aug 2020 21:49:26 +0000

Long-distance palm weevil flyers threaten California date palms ilseu Tue, 08/11/2020 - 14:49 More CNAS in the Media Andrew Porterfield | Entomology Today July 16, 2020

ENTOMOLOGY TODAY - How long and how fast an invasive insect travels are important questions to determine the insect’s impact on plant (or animal) hosts. A new study by University of California, Riverside, researchers shows that Rhynchophorous palmarum, also known as the American or black palm weevil, can fly much further and faster than expected.

The results, published in June in the Journal of Economic Entomology, do not bode well for the southern California date palm industry.

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Department of Entomology

Mark Hoddle

Want to save your citrus trees? Start a full-fledged insect war

ilseu — Fri, 24 Apr 2020 21:37:36 +0000

Want to save your citrus trees? Start a full-fledged insect war ilseu Fri, 04/24/2020 - 14:37 More CNAS in the Media Jeanette Marrantos | LA Times April 24, 2020

LOS ANGELES TIMES - Growing citrus is a dicey business these days in Southern California, and not at all recommended if you live within a two-mile radius of a tree infected with Huanglongbing disease — a.k.a. HLB or citrus greening disease. However, if you live outside a “red zone” and you’re willing to actively fight the disease, then yes, it’s still possible to grow limes for your margaritas.

But you’ll have to be ruthlessly proactive by declaring brutal warfare on the ants in your yard while embracing a tiny parasitoid wasp that eats its living prey from the inside out.

HLB is a bacterial disease spread by the tiny Asian citrus psyllid that loves to suck the sap from tender new “flush” growth on citrus and then lay its eggs. If the psyllid sups on a tree with HLB, it spreads the disease to every other tree it visits, and once infected, there is no cure.

The University of California’s department of Agriculture and Natural Resources has created an interactive map that identifies hot zones of infection: in Southern California they’re mostly in the four-corners area where Los Angeles, Orange, Riverside and San Bernardino counties meet. Enter your address and it shows how close your home is to those infection areas.

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Find out if your area is affected with UC ANR's interactive HLB proximity map:

View interactive map

Check your citrus trees for Asian citrus psyllid:

View UC ANR video on youtube

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Department of Entomology

Elizabeth Grafton-Cardwell

UC Agriculture and Natural Resources

Riverside hosts influential invasive plant conference for the first time

ilseu — Mon, 28 Oct 2019 21:15:13 +0000

Riverside hosts influential invasive plant conference for the first time ilseu Mon, 10/28/2019 - 14:15 More College News Jules Bernstein | Inside UCR October 25, 2019

Riverside recently hosted the California Invasive Plant Council symposium for the first time in the history of the decades-old gathering.

“Having the symposium here underscores UC Riverside’s long-standing and growing importance to the field of land management and invasive plant species research,” said event committee member Lynn Sweet, a plant ecologist at UCR’s Palm Desert Center.

Sweet presented on Sahara mustard, an invasive plant that has “exploded in the last 50 years in the Coachella Valley, competing with native species and crowding out some of the popular wildflower displays,” Sweet said.

Several hundred people traveled from across the state to attend the Oct. 15-18 event at the Riverside Convention Center. The crowd was a mix of professional government and nonprofit land managers, graduate students, university faculty members, and others who came to share strategies for protecting plants, animals, and open spaces under the increasing pressure of climate change.

“For me, one of the highlights was being exposed to some out-of-the-box thinking about how to tackle thorny weed management issues on really large landscapes,” said Loralee Larios, an assistant professor of botany and plant sciences at UCR.

One example of an innovative approach to fighting invasive species presented at the conference is to use a pressure washing hose to kill weeds as an alternative to herbicides. The chemicals can accumulate in the environment and cause problems for other living things, but water of course is harmless. Another innovation is using drones or satellites to identify areas most in need of weed treatment and where topography would result in the most successful treatment.

“This conference is really a fantastic opportunity for professionals and researchers to share what they know, what’s being done now, and what more could be done to protect our open spaces,” Larios said.

In her own laboratory on campus, Larios and her students are trying to understand how environmental change might encourage the growth of various invasive plant species, and how to use that information to mitigate negative impacts.

The Larios lab is paying special attention to a nonnative invasive plant called Stinknet, a very fragrant form of chamomile spreading across western Riverside County and other parts of California.

“It’s invading habitats that traditionally house several endangered animal species that need more open bare ground,” Larios said. “Stinknet creates a dense mat that makes it hard for animals like the Stevens kangaroo rat or the cactus wren to move around and feed on the native plants they prefer.”

One of the symposium’s activities included a field trip to UCR’s Motte Rimrock Reserve in Perris Valley to observe the Stinknet invasion and highlight research to control it, like the work coming out of Larios’ lab.

The weeklong event featured several UCR speakers, including entomologist Mark Hoddle, director of UCR’s Center for Invasive Species Research; and Norm Ellstrand, a distinguished professor in the Department of Botany and Plant Sciences, who has a long history of studying invasive plant species.

Readers wondering how they can help control the spread of invasive plants and pests in California can head to the Cal-IPC website, which includes resources for residents. These include suggestions for plants to avoid in landscaping, beneficial alternatives, and places where people of all ages can volunteer for land management projects.

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Center for Invasive Species Research (CISR)

Department of Botany & Plant Sciences

Mark Hoddle

Eating Insects: Like Them Stir Fried or Curried?

edraws — Tue, 18 Jun 2019 20:04:24 +0000

Eating Insects: Like Them Stir Fried or Curried? edraws Tue, 06/18/2019 - 13:04 More College News October 01, 2013 Riverside, Ca

UC Riverside's Mark Hoddle helps Canadian research team win the Hult Prize

On Sept. 23, the Clinton Global Initiative awarded the Hult Prize, worth $1 million, to a team of student entrepreneurs at McGill University, Canada. Mark Hoddle, the director of the Center for Invasive Species Research at the University of California, Riverside, served as a consultant to the team whose goal was to combat hunger and nutrition deficiencies in impoverished regions by improving insect-based meals.

Hoddle, an extension specialist in entomology and an expert on both the red palm weevil and weevil farming in southeast Asia, traveled to Thailand Sept. 14-19 with a member of the winning team to assess red palm weevil farming practices.

“I did a whirlwind tour of the weevil farms with McGill University’s Gabriel Mott, an MBA student, and prepared a report and visuals from the trip for the package his team submitted for the Hult Prize,” Hoddle said. “On Sept. 23, I watched on the internet as the team pitched live in New York City in front a really big audience and an auspicious judging panel that included Nobel Peace Prize laureates, and guess what – the team won!”

A dish of cooked weevil larvae. Photo credit: Hoddle Lab, UC Riverside.

Entomophagy is the consumption of insects by humans for food — an ancient practice that tends to be concentrated in certain parts of the world, notably tropical and sub-tropical regions, where there is a diversity of large insects.

“Insects are excellent low cost sources of protein and essential nutrients,” Hoddle said. “Edible insects can often be sustainably harvested from wilderness areas and have very low carbon footprints if farmed for personal consumption or as a commercial enterprise.”

Due to interest in eating insects because of their nutritional and environmental benefits, and because a wide diversity of insects are eaten daily by millions of humans, there is interest in the viability of mass collection, production, or farming of certain species for food.

“This is already being done in some areas, with a notable example being the mass collection and subsequent preparation and sale of chapalines, a type of grasshopper, in Oaxaca, southern Mexico,” Hoddle said. “Another insect that has significant potential for mass production or farming are palm weevils. Larvae and pupae of these species are widely eaten in southeast Asia and farmed to a limited extent in some countries, notably Thailand.”

McGill University’s Gabriel Mott shops for red palm weevil larvae in Thailand. Photo credit: Hoddle Lab, UC Riverside.

More information is available on Hoddle’s blog.

Watch a 2012 video of Hoddle eating larvae.

Next, Hoddle plans to set up weevil farms in Ghana with the McGill team.

“They have a native palm weevil that is eaten but the larvae are not farmed,” he said.

There are three main ways red palm weevil larvae and pupae are prepared for eating: (1) stir-fried in a wok (very common), (2) prepared as a curry dish with vegetables, or (3) battered and deep fried. Sometimes live larvae may be eaten after floating in soy sauce. Cooked red palm weevil larvae and pupae provide a substantial and hearty meal either on their own or when supplemented with additional vegetables and rice or noodles.

Weevil larvae are very easy to farm, production costs are low, and profit margins are potentially high. Preparation of weevils, especially larvae, for cooking is straight-forward.

“Because larvae lack legs and antennae, it is easy to ‘disguise’ the fact that they are insects when prepared for consumption,” Hoddle said. “This is especially true when larvae are battered and deep fried. Cooking weevil larvae and pupae in creative ways, and perhaps developing a catchy marketing name, may enhance marketability and acceptance as a food, especially in areas where entomophagy is uncommon or insects are viewed as unclean and unsuitable for eating.”

In Thailand, Nittaya Ummarat, a post-graduate researcher at the UC Kearney Agricultural Research Center, helped translate Thai into English.

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Center for Invasive Species Research (CISR)

Mark Hoddle