- Author: Saoimanu Sope
Sugar-feeding ants protect pests that infect trees and damage the fruit they bear. Insecticides are often a go-to solution, but may kill beneficial insects in the process, too. Thankfully, Mark Hoddle, University of California Cooperative Extension entomologist and biological control specialist at UC Riverside, together with UCR colleagues in chemical engineering, developed a biodegradable hydrogel baiting system that targets ant populations, which protect sap-sucking pests from their natural enemies. Control of ants allows beneficial parasitoids and predators to greatly reduce pest populations.
Deciding to expand Hoddle's research was a “no-brainer” according to David Haviland, UC Cooperative Extension farm advisor in Kern County.
Haviland is investigating active ingredients that can be effectively used in hydrogel baiting systems. His research builds on Hoddle's use of alginate gels, also known as water beads, soaked in sugar water to control Argentine ants.
“What we're doing in California can benefit places like Florida, Texas, Mexico and beyond,” Haviland said.
The Hoddle lab conducted two years of orchard research showing that when ants are controlled, the amount of citrus flush infested with Asian citrus psyllid (ACP), a mottled brown insect that vectors the pathogen causing citrus greening, decreases by 75%. Citrus flush refers to newly developed leaves.
“But benefits are not restricted to just ACP with Argentine ant control, as natural enemies destroy colonies of other sap-sucking pests too,” said Hoddle. “For example, citrus mealybug infestations on leaves were completely eliminated by natural enemies, 100% control, while densities of fruit infested by mealybugs were reduced by 50%.”
The Hoddle lab's success inspired Haviland to consider how this approach will fare in different regions of the state where there are different crops, different pests and different ant species.
Haviland has worked for many years on solid baits that are effective and affordable for ants that feed primarily on protein, like fire ants in almonds, but successful control measures for sugar-feeding ants that drink their food have been elusive.
“Therefore, we're using hydrogels to essentially turn a liquid bait into a solid, making it effective and commercially adoptable,” Haviland said. He and his team are assessing whether active ingredients that undoubtedly work against ants, like thiamethoxam, maintain their effects in a hydrogel system.
Unlike Hoddle's biodegradable alginate gels, Haviland is relying on acrylamide gels that are similar to the absorbing material you would find in a diaper. These gels are not organic, but are currently accessible on a commercial scale, and have been shown to be effective in wine grapes on the North Coast by a Cooperative Extension advisor in Napa County, Monica Cooper. Haviland's current research efforts are focused on citrus, table grapes and wine grapes in the San Joaquin Valley, and on lemons on the coast.
The primary challenge now is navigating pesticide regulations and registration.
“This is cutting-edge research,” Haviland said, and manufacturer labels for the products being used need to be updated to include hydrogels as an approved use. This process takes time. Additionally, adding new product uses needs to make economic sense for the manufacturer.
Hoddle and Haviland's research can provide data for adding these methods to the product labels.
“If we can show that this tech works against lots of pests, lots of ant species, in lots of different crops across California, hopefully we'll achieve a critical mass of benefits that motivates product manufacturers to make modifications to their labels,” said Haviland.
Haviland is hopeful about the process, and said he believes that UC ANR is in a prime position to lead innovation for an issue that requires collaboration among specialists, advisors and the industry.
- Author: Mike Hsu
John Karlik, UC Cooperative Extension advisor in Kern County for environmental horticulture and environmental science, will retire July 1. Karlik began his work in Kern County in 1984 with an emphasis on the commercial rose plant industry and local horticulture outreach.
Karlik's teaching activities included five levels of 12- to 15-week horticulture education classes offered in three locations in Kern County, usually two or three classes held each year. For the past 25 years, he has collaborated with Darrell Feil, co-owner of Abate-a-Weed in Bakersfield, to hold landscape management seminars that connect community members with experts on a wide range of topics.
“What I love about John is a couple of things: first, his knowledge base is amazing – he's a treasure of Kern County, for what he's done education-wise,” Feil said. “And second, he has a very active mind – and so many people benefit from that in our community.”
Karlik expanded his teaching to include 10 horticulture study tours to gardens and landscapes of Europe and Asia, and the photographs from those visits enhanced his outreach and contributed to his chapters on landscape design in the Arizona and UC Master Gardener Handbooks.
He earned his B.S. in soil science from the University of Minnesota and M.S. in horticulture from Michigan State University.
Taking advantage of UC Agriculture and Natural Resources' flexibility and sabbatical leave, he completed a doctorate at UCLA in Environmental Science and Engineering, and changed his research focus to air-quality-related projects. That led to a lecture series on atmospheric science and policy, including climate change, which Karlik offered annually for 15 years as a visiting professor at Central European University in Budapest, and resulting in a service award from that institution.
In recent years, he led four tours to study ecosystem response in the still-radioactive Exclusion Zone at Chernobyl, Ukraine, site of the world's worst nuclear accident.
In response to the COVID-19 pandemic, Karlik shifted from in-person classes and offered 75 hour-long Zoom presentations on horticulture, landscape design, climate change and environmental science topics, finding an audience in California and in other states.
Karlik also has held a variety of positions in ANR committees, including Academic Assembly Council and the Communications Advisory Board.
“I especially appreciate the many collegial relationships I have within UCCE, ANR, and on several campuses,” Karlik said. “Authorship on many publications reflects those relationships.”
In retirement, Karlik expects to offer assistance at the UCCE office in Kern County and as an editor for a forthcoming ANR book. He intends to pursue interests in instrumental music and the study of languages.
“We've been really blessed to have a guy like John around,” Feil said.
- Author: Yolanda S. Lopez
- Contributor: Nora Lopez
- Photographer: Shawna Rogers
- Contributor: Shelby MacNab, MPA
USDA Secretary Tom Vilsack proclaimed August 2-8, 2015, National Farmers Market Week. Here in the Central Valley local farmers' markets are selling many delicious seasonal fruits and vegetables. To celebrate the week, we visited The Market on Kern and Manchester Center Farmers' Market to ask shoppers why they shopped at local farmers' markets. What we found were affordable prices, a since of community and some of the best looking produce around.
What brings families to the markets?
Yolanda was on a mission to find out. The answer? They came for a variety of reasons, from freshness to cost.
An Abundance of Affordable Produce Available
What a Great Week!
We weren't able to make it to all of the local markets in the Central Valley this week, but feel lucky to have so many nearby. We often refer our class participants to local markets to encourage them to incorporate more fruits and vegetables into their meals and snacks. To locate a market near you, use this directory.
For some of our favorite produce recipes, visit the USDA's What's Cooking website.