- Author: Julie Di Blasio
Invasive shot hole borer (ISHB) infestations have been identified in Ventura County since 2015 but have not significantly spread. Discovery of the pest/disease complex was found in late 2018 in the urban forest of Meiners Oaks. Citizens Journal recently published an article about the removal of a tree that was at risk for amplifying the local infestation and causing potential other community harm.
The Ventura Agricultural Commissioner supervised the removal of the tree, using grant funds for this purpose from CAL FIRE. The box elder was located on private property and considered to be a hazard to extend the infestation.
UCCE Ventura has been collaborating to address ISHB with UC insect, disease, education specialists, Ventura County Agricultural Commissioner, CAL FIRE, US Forest Service, several other agencies and non-government organizations. We are locally active in monitoring and outreach. Ventura County Master Gardeners Invasive Pests Outreach Group augments our work through their efforts to educate the public, firewood users and vendors.
Below is a video produced by California Releaf, a nonprofit organization that works to empower grassroots efforts and build strategic partnerships that preserve, protect, and enhance California's urban and community forests. It's been edited for length.
For more information about ISHB, you can also visit the UCANR website.
- Author: Rose Marie Hayden-Smith
Learn About California Agriculture
Join us on Thursday, May 21st, 9:30 am PST, for Part 2 of a webinar series on California agriculture, where we'll learn about major crops and production areas. This webinar will feature UCCE Ventura County advisors Andre Biscaro and Ben Faber. Watch it live or view after on YouTube. Part 1 is up. This is an ideal webinar series for the home classroom.
Fumigants and Non-Fumigant Alternatives: Regulatory & Research Updates
Growers, PCAs, applicators and supervisors of fumigant and non-fumigant technologies and decision makers should plan to attend this free, virtual educational outreach event, scheduled for Monday May 29th from 8:00 a.m. to 12:00 p.m. This workshop is open to the public. Although targeted to strawberries, most of the learning will generally apply to other crops. The program is being hosted by Dr. Oleg Daugovish, who serves as the Strawberry and Vegetable Crop Advisor for UCCE Ventura County.
Topics include:
- Most pertinent regulatory requirements for fumigant use and application
- Industry updates on fumigant and non-fumigant tools use
- Fumigant application based on need within fields
- Soil-borne pathogen management
Continuing Education Units are available: 1.5 hours of "Other" and 1.0 hours of laws and regulations have been applied for from California Department of Pesticide Regulation (DPR).
Registration is required and participants will receive a link and instructions prior to the workshop. Register here.
Announcing Treemendous Learning Webinars for Middle and High School Students
Join us on alternate Tuesdays in May and June, 3:00 pm to 4:00 pm, for this opportunity designed for middle and high school students. Treemendous Tuesdays is a collaboration of U.S. Forest Service, Los Angeles Center for Urban Natural Resources, California Project Learning Tree, California 4-H, and UC Agriculture & Natural Resources
Five webinars will be hosted every other week starting May 5 and ending June 30. These events are free and registration is required.
- May 5: Invasive Species (invasive shot hole borers)
- May 19: Invasive Plants & Trees
- June 2: Benefits of the Urban Forest
- June 16: iTree
- June 30: Living with Fire
Register at https://ucanr.edu/survey/survey.cfm?surveynumber=29846
New Resource to Diagnose and Manage Plant Disease
UC's Integrated Pest Management Program has a new Pest Notes publication available, which provides information to help diagnose and manage Anthracnose, fungal diseases that can impact many deciduous and evergreen trees and shrubs. These diseases can also infect vegetables, flowers, fruit and turfgrass in some regions in California. Dr. Jim Downer, an Advisor in our UCCE Ventura County office, is a co-author.
Preparing for Fire Season
UC ANR has organized an electronic portal - Homeowner's Wildfire Mitigation Guide - that contains a wealth of resources to help homewoners prepare for fire season. Please visit our Fire Resources and Information page for the latest research and information.
Follow Us on Facebook and Instagram
We'd love to interact with you on social media. Like our Facebook page and visit us on Instagram.
- Author: Ben Faber
This is a cross-post from the "Topics in Subtropics" blog.
Join us on alternate Tuesdays in May and June, 3:00 pm to 4:00 pm, for this opportunity designed for middle and high school students. Treemendous Tuesdays is a collaboration of U.S. Forest Service, Los Angeles Center for Urban Natural Resources, California Project Learning Tree, California 4-H, and University of California Agriculture and Natural Resources.
Five webinars will be hosted every other week starting May 5 and ending June 30. These events are free and registration is required. Flyer is attached. Dates, topics, and link to registration are below.
Please share this online opportunity with organizations, community members, teachers, parents, and students. We look forward to giving students a glimpse of the wonders and benefits that trees offer!
- May 5: Invasive Species (invasive shot hole borers)
- May 19: Invasive Plants & Trees
- June 2: Benefits of the Urban Forest
- June 16: iTree
- June 30: Living with Fire
Register https://ucanr.edu/survey/survey.cfm?surveynumber=29846
- Author: Annemiek Schilder
In this weekly blog, Dr. Annemiek Schilder, Director, UCCE Ventura County and Hansen Agricultural Research and Extension Center, shares her observations about the natural world across the seasons. As she says:
"Gently observing your surroundings with curiosity will teach you some amazing things. There are so many fascinating things happening under our noses, only wanting for an observant eye."
During a recent stroll through the Master Gardener Demonstration garden at the Hansen Agricultural Research and Extension Center, a narrow-leaf milkweed plant with stems and leaves covered in yellow caught my eye. A closer look revealed teeming masses of yellow aphids along the stems, as if festively dressing up the plant. But aphids are never a festive sign to the gardener as their voracious feeding stunts plant growth. In addition, their sugary excretions may attract ants and promote unsightly fungal growth called sooty mold.
Narrow-leaf milkweed (Asclepias fascicularis) is a perennial plant native to California and an important food source for the caterpillars of monarch butterflies along their migration route. Milkweed plants produce chemicals called cardenolides (cardiac glycosides) that monarchs store in their bodies to protect themselves from predators. Can you guess what part of the body these chemicals act on? Indeed cardenolides speed up the heart rate, making for a rather unpleasant experience for a bird looking for a tasty meal. Narrow-leaf milkweed plants actually have very low levels of cardenolides, but the monarch's striking color pattern is enough to signal toxicity to would-be predators.
Aphids make milkweed plants less hospitable for monarch caterpillars. The striking yellow aphids −Aphis nerii, also called milkweed aphids or oleander aphids−feed on plants in the dogbane family, including oleander, milkweed and periwinkle. They have a yellow pear-shaped body with black legs, antennae and cornicles. Cornicles are the stovepipe-like projections on the aphid's back used to secrete a wax-like substance for self-defense. Aphids are typically wingless until they get too crowded and develop winged individuals that fly away in search of new host plants.
Aphids feed by inserting their mouth parts, which are shaped like a straw, into the plant, sucking up plant sap which contains all the necessary nutrients for the aphid to thrive. The extra sugar and water are excreted as honeydew. Milkweed aphids are able to rapidly colonize plants in the spring and early summer through parthenogenesis, a process whereby female aphids produce female offspring without mating. The aphid daughters, which are exact clones of their mothers, quickly start producing their own babies. In addition, they bypass the egg laying phase by giving birth to live young, which is called vivipary. Looking through a magnifying glass, you may see the little baby aphids being born right in front of your eyes!
As I was taking some close-up photos, I noticed the aphids intermittently twitching, almost in unison. This strange phenomenon, exhibited by this particular aphid, is called CTKR (Collective Twirling and Kicking Response). It is a collective defense mechanism against natural enemies! By simultaneously twirling their bodies and forcefully kicking their hind legs they discourage natural enemies like parasitoid wasps from attacking them. If you look closely, especially later in the season, you may see evidence of this type of parasitism: little puffed-up aphid bodies with a hole in the middle. These aphids have been parasitized by a wasp larvae which molted into adults and escaped through the hole.
Aphids are like sitting ducks: they usually remain in place while feeding. They will only move if their food runs out or something is irritating them. That makes them a convenient prey for the lady beetle, a very effective natural enemy. In the picture, you can see an adult lady beetle as well as a lady beetle larva, which looks like a tiny black alligator, feeding on aphids. They can eat hundreds of aphids per day and thousands in a life time! Lady beetles are good friends indeed.
Related Reading:
- Author: Rose Marie Hayden-Smith
Nearly two tons of fruit and vegetables grown at UC's Hansen Agricultural Research and Extension Center (HAREC) in Santa Paula have been donated to Food Forward and the Ventura Unified School District (VUSD), destined for children and families.
Some of the vegetables – planted by volunteers and farm staff - became available when UC HAREC's farm field trips were canceled due to COVID-19. Other vegetables were harvested from the student farm located at HAREC, a partnership with VUSD and the city of Ventura. Kale and lettuce at the student farm were planted by youth from DATA and Montalvo schools.
Every fall and spring, volunteers from the UC Master Gardener program propagate seedlings for schools, bundling them into variety packs of vegetables and herbs, which are given to schools with gardens. Because of COVID-19, plants were given to schools for direct distribution to families. Ventura Unified School District staff partnering in this effort include Kara Muniz, Director of Food and Nutrition Services; Ashely Parrish Decker, Nutrition Educator, who runs the Student Farm; and Alise Echles, RDN.
Additional fruit and vegetables were harvested from HAREC's citrus demonstration area, the site's educational gardens and the farm grounds.
UCCE's education program manager Susana Bruzzone-Miller said, “We are saddened that spring field trip season is cancelled and miss the sound of children delighting in harvesting, sometimes for the very first time. But, it warms my heart that our field trip garden can help feed so many families in need.”
John Antongiovanni, farm manager, worked with the farm staff to organize the harvest. He said, “Working together during this difficult time is very rewarding.”
Food Forward is a gleaning organization that helps residents turn the surplus produce grown on their property into a nutritious food source for local communities. Rick Nahmias, founder and executive director, indicated that the Food Forward Backyard Harvest team remains active, and may be reached via phone at 805.630.2728 or email.
