- 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
This week marks the 50th anniversary of Earth Day. This year, consider celebrating the day with gardening and other stay-at-home resources curated by your local UCCE office.
History of Earth Day
Earth Day was launched in 1970. Many factors contributed to the call for a national day focusing on environmental stewardship, including the publication of Rachel Carson's Silent Spring - serialized in the New Yorker - and the catastrophic oil spill that occurred off the coast of Santa Barbara in 1969. The Santa Barbara oil spill galvanized U.S. Senator Gaylord Nelson (D-Wisconsin) to call for a national day of locally inspired and organized "teach-ins" on the environment - a national "Earth Day." The Earth Day model was inspired by the spirit of campus activism at the nation's colleges and universities. It wasn't top-down, but rather a grassroots effort that encouraged communities to develop educational and service events around issues and topics important to them.
Earth Day struck a chord; some estimates suggest that 1 in 10 Americans participated in the first events. Earth Day is widely credited with "sparking" the modern environmental movement. Landmark environmental legislation swiftly followed (including the Clean Air Act, Clean Water Act and Endangered Species Act). The Environmental Protection agency was founded that same year. Twenty years after its launch, Earth Day became a global movement.
You can learn more from the Earth Day Network by linking to this website.
Home Garden Resources
There is a wave of renewed interest in gardening as a result of the COVID-19 pandemic. Learn more about "crisis" gardening - and a new "Victory Garden" movement - in this article from the New York Times.
Closer to home, we have a wealth of gardening resources for you.
One of our favorites is the California Garden Web, designed by our UC Master Gardeners. You'll find a wealth of gardening information and a helpful glossary.
Ventura County is blessed with a wonderful growing climate and many of us have backyard fruit trees. Learn more about cultivating and caring for your home orchard here.
Resources for the Home Classroom
Many of us are working with our children in home classrooms. The UC 4-H Youth Development Program has a range of resources available to engage young learners. In honor of Earth Day, take a look at our 4-H Vegetable Gardening Project sheet. We also recommend our 4-H Water Conservation Project sheet, which provides engaging, science-based activities the entire family can enjoy. 4-H is one of the oldest youth development programs in the nation and we'll be sharing other educational resources in upcoming posts. #Head #Heart #Hands #Health.
Be Kind to the Earth by Reducing Food Waste
Nearly 40 percent of the food produced in the U.S. is wasted and much of that waste ends up in landfills (definitely not good for our environment or the economy).
The National Resources Defense Council estimates that the average family of four throws out nearly 1,000 pounds of food each year, wasting roughly $1,500.
Consumers as a group waste more food than farms, grocery stores or restaurants. For tips on ways you can reduce #FoodWaste, click here.
History lesson: The image on the left is a poster that was used during World War I and World War II to promote food conservation. First printed in 1919, it contains tips that are helpful today.
This image is from a collection held by the Museum of County. Photographer: Aysen Tan.
Related reading: What a World War I Poster Can Teach Us About #FoodWaste.
Thank you, Volunteers!
This week is National Volunteer Week and we want to thank the hundreds of volunteers who are part of UCCE Ventura...and who make our work possible. Thanks to our 4-H, Master Gardener and HAREC volunteers. You are central to our mission and we value you. Youth, Families and Communities Education Program Manager Susana Bruzzone-Miller created this video to express our appreciation.
COVID-19 Resources
Our COVID-19 landing page provides links to important resources about the pandemic, including information for the agricultural community. In response to the coronavirus (COVID-19) illness, our office is closed for face-to-face service through May 15th. While we regret the inconvenience, these are the precautions we are taking to support one other and comply with University, local, county and state government recommendations. Our staff is telecommuting and can be contacted via phone and email. We are here to serve you.
Stay safe.
- Author: Cris L. Johnson
The Master Gardeners of Ventura County have once again earned awards for their display at the Ventura County Fair. This year's ribbons were won for Best of Division, Best Plant Material and Best Design with additional award plaques for Best Interpretation of Fair Theme and overall outstanding participation.
The winning Master Gardener display uses humor and gardening expertise to educate visitors on ways to use drought tolerant plants, so important in dry southern California. In an area subject to periodic drought conditions this display is particularly timely as county residents cope with low rainfall and dropping water levels. Informational flyers and Master Gardeners are on hand for visitors to learn more about the program and drought tolerant plants and practices.
Master Gardeners are recruiting for this year's trainee class. If you are interested in learning more about this successful program that serves Ventura County, link to their webpages here.
- Author: Cris L. Johnson
Join the UC Ventura County Cooperative Extension's Master Gardeners at their summer workshop, "All About Roses, Plant Propagation."
Our hard-working Master Gardeners present a workshop for each season of the year and this one is devoted to sharing information about pruning, watering and fertilizing roses and dealing with any pesky pests.
Time: 8:15 am - 12:00 pm
Location:
Hansen Agricultural Center
14292 W. Telegraph Rd.
Santa Paula, CA
(Use Briggs Rd. Entrance)
The Master Gardeners love to share their expertise and love of gardening. Workshops are held on Saturdays so more members of the public can participate.
Cost: $30 (includes continental breakfast and snacks)
To view the flyer, please click here; or to online register.
- Author: Cris L. Johnson
Here you will learn how to have flowers available all year long to arrange in your home. The Master Gardeners will teach you the principles of flower gardening and techniques to create lovely floral arrangements.
Master Gardener workshops are open to the public and can fill up quickly.
Date: Saturday, June 22, 2013
Time: 8:15 am - 12:00 noon
Location:
Hansen Agricultural Center
14292 W. Telegraph Rd.
Santa Paula, CA
Cost: $30.00 (includes continental breakfast and snacks)
Click to register and learn more about the workshop.
