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From the UC Blogosphere...

Hide the Cactus!

Hide the cactus! There's a Mexican cactus fly in our midst.

A large black fly hovers over a Mexican sunflower (Tithonia) in our bee garden and then drops down to sip some nectar. At first glance it looks like a carpenter bee but this one hovers like a syrphid fly, aka flower fly or hover fly.

"Hover fly," I say.

Entomologists Martin Hauser, Lynn Kimsey and Robbin Thorp quickly identified the critter.

Hauser, senior insect biosystematist with the Plant Pest Diagnostics Branch of the California Department of Food and Agriculture, says it's in the genus Copestylum (with over 350 species in the new world) and figured it to be the species,  mexicanum, commonly known as the Mexican cactus fly.

Said Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis: "Nice, this is actually a kind of syrphid flower fly, better known as a cactus fly. The larvae breed in rotting cactus tissue."

Native pollinator specialist Robbin Thorp, emeritus professor of entomology, also figured it to be a Mexican cactus fly, Copestylum mexicanum.  "It's commonly known as a cactus fly (Syrphidae, Tribe Volucellini).  "It used to be in the genus Volucella, But now it's in the genus Copestylum."

This fly is not small. It's about 3/4 of an inch long. It lays its eggs in rotting plant material "and they really like rotting cacti," Hauser commented. "As far as I know, they only go into dying cacti and do not attack healthy cacti…. But there is actually not much known about their biology."

The resident cacti expert at our house is worried, showing his best prickly pear expression. He quickly canvasses the yard. Whew! No rotting cacti. All thriving and in good health.

So far, so good...

Black hover fly, aka Mexican cactus fly, sipping nectar from a Mexican sunflower (Tithonia). (Photo by Kathy Keatley Garvey)
Black hover fly, aka Mexican cactus fly, sipping nectar from a Mexican sunflower (Tithonia). (Photo by Kathy Keatley Garvey)

Black hover fly, aka Mexican cactus fly, sipping nectar from a Mexican sunflower (Tithonia). (Photo by Kathy Keatley Garvey)

Side view of the black syrphid fly, a Mexican cactus flower. (Photo by Kathy Keatley Garvey)
Side view of the black syrphid fly, a Mexican cactus flower. (Photo by Kathy Keatley Garvey)

Side view of the black syrphid fly, a Mexican cactus flower. (Photo by Kathy Keatley Garvey

Mexican cactus fly ready to take off. (Photo by Kathy Keatley Garvey)
Mexican cactus fly ready to take off. (Photo by Kathy Keatley Garvey)

Mexican cactus fly ready to take off. (Photo by Kathy Keatley Garvey)

Posted on Tuesday, September 30, 2014 at 5:29 PM

Bagrada Bugs

 

Bagrada Anyone?

By Andrea Peck

 

 What are the red and black bugs that I am seeing on my arugula?

 

It sounds like the infamous bagrada bug. Also called the painted bug, this insect is a member of the stink bug family. Its name sounds like a fancy dance step and its appearance, shiny black with orange-red and white highlights, is equally slinky. Often the male and female will bustle about like interconnected locomotives. Often is a key word here because this is a shameless mating maneuver that occurs often. You can expect lots of little bagradas swimming unabashedly amongst your plants. Newly hatched bagradas are small, but their dramatic orange-red coloring makes them highly visible.

In order to flourish, bagrada bugs need to host on plants in the mustard family. Despite their preference for cole crops (broccoli, cabbage, cauliflower, kale and turnip) that grow best in cold weather, the bagrada is dependent on warm temperatures for development. The adult is most apt to fly in temperatures of 85°F.  You would think this would be a limiting set of requirements, but the invasive bagrada is a determined sort. During the heat waves of late summer, a bagrada family visit may erupt into a full scale infestation. At this time, numbers may reach such levels that the bagrada may become an equal opportunity eater and vary its diet towards tomatoes, peppers and melons. Small plants and seedlings are highly prized by this gourmand.

The bagrada literally makes mincemeat of its food source. The bagrada's tongue serves as a blending attachment, digestive juice injector and straw. The interior of your plant's leaves and stems don't stand a chance when this insect inserts its needle-like mouthparts, breaks down the contents and then slurps up the liquid meal like a smoothie.

Control can be gained culturally by removing the insect's host plants – those in the mustard family – near planting areas. Interestingly, removal of the pest is possible by using a hand-held vacuum. Row covers with very fine netting provide protection by excluding the pest.

 

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Posted on Monday, September 29, 2014 at 7:44 PM

Daily Life For Master Gardeners

A Bug of Color

By Andrea Peck

 

 A blond in a red dress can do without introductions – but not without a bodyguard.

-Rona Jaffe

 

From afar, cochineal scale may look like a fungus or mold that has infected your prickly pear or nopal cactus (opuntia). If the pest takes up a small space, you may write the damage off to a bit of dead tissue, something that you might lop off if you are industrious and in possession of armor.

But, make no mistake, cochineal scale is a small insect. The female is usually what you see on your plant – she lives out her life, breeding and eating on the cactus, while the male, blessed with wings, takes flight on insect adventures. Juveniles are mobile enough. Once settled on a feeding spot, they produce long wax filaments. Soon they move to the edge of the cactus pad and are taken by the wind in the hopes of landing on unchartered territory. The female stays put.

This is no pretty bug. But, her power is fierce.

Underneath that unexceptional appearance lies a chemical – carmine – which, when eaten tastes bitter. This is her defense, since clearly she is defenseless lying atop a plant that grows in a desert climate without the ability to flee. What's a lady to do besides resorting to chemicals? She has her devices.

But, scratch beneath the surface (literally) and you have a grander tale of carmine and color. Carmine may be bitter to the taste, but it is candy to the eye. And if you are facile in collecting the creature, you know that it produces a rich red color that can be permutated into many shades, from pink to deep maroon. Its useful origins trace back to the Aztecs. The Spaniards eventually got a hold of it. From there it became a hot commodity. The British were said to hire pirates to confiscate gold and valuables – and cochineal insects – from aboard ships. The famous British red coat was colored with the cochineal. Betsy Ross herself used the insect dye to color the red stripes of our first flag. Art of all kinds utilized it.

The 1900's brought synthetic dyes and cochineal went out of fashion for a while. This did not last long. Synthetic dyes, it turns out, were carcinogenic.

The dye continues to be useful despite some relatively recent uproar about bugs in our foods. It was probably not a pretty sight when mothers around the country discovered that their red velvet cupcakes had bugs in them.

Their worry is not completely unfounded, however, as some cases of anaphylactic reactions and asthma has been attributed to the dye. The FDA did concede to pressure by requiring food products to be labeled. You have to read your labels carefully, however. Any number of names may stand in for carmine. (Carmine, cochineal extract, Red 4 and E120 are a few that I have come across).

Foods that are red or pink, such as yogurt, ice cream, candy and juice may contain the insect. Interestingly, cochineal is considered one of the few safe ingredients in eye cosmetics and is used in almost all types of cosmetic products.

The cochineal scale is a testament to the power of insects. Maybe its cardinal color is no accident. The color red, a symbol of love and hate, power and courage has had an honored place in history. Who knew that a lowly bug was responsible?

Below is a great video which shows the process of dying wool.

http://www.youtube.com/watch?v=2k_FJoaOQGA

Also, there is an entire book devoted to the subject:

A Perfect Red by Amy Butler Greenfield

 

 

 

Posted on Monday, September 29, 2014 at 7:31 PM

Enlightenment 'After Dark'

Jeweled beetles at the Bohart. (Photo by Kathy Keatley Garvey)
"After Dark: When Tricks Are Treats."

That's the theme of San Francisco's Exploratorium Pier 15 event on Thursday night, Oct. 2.

Graduate student Ralph Washington of the UC Davis Department of Entomology and Nematology, will be staffing the Bohart Museum of Entomology table at the event, open only to adults 18 and over. 

Washington, who studies with major professor Steve Nadler and volunteers at the Bohart Museum, will showcase the “oh my” drawers, so named because onlookers exclaim “oh my” when they see them; and live animals from the petting zoo,  which include Madagascar hissing cockroaches,  walking sticks and millipedes. He also will show a PowerPoint presentation about camouflage and deception in the insect world. 

The event will take place from 6 to 10 p.m., at Pier 15, located at Embarcadero at Green Street, San Francisco. General admission is $15; for members, it is $10.

“After Dark” is a mixture of theater,  cabaret and a gallery, according to its website.

Tabatha Yang, education and outreach coordinator at the Bohart Museum, said "After Dark" is aimed at young adults.

From the website: 

“Delve into the science behind deception at After Dark. Find out how expert wine detective Maureen Downey exposes costly counterfeits—without uncorking a bottle. Glimpse the blurred margins between science and art in Victorian spirit photography with Fine Arts Museums of San Francisco curator Melissa Buron, and walk through a virtual mirror staged by Exploratorium physicist Paul Doherty. Play with exhibits exploring the nature of perception, including a room-sized “Vanishing Act.” Encounter the uncanny in the mischievous mentalism of Brad Barton, Reality Thief, and let magician and Exploratorium scientist Luigi Anzivino show you how the odds can be stacked against you in a seemingly innocent game of chance. Learn the tricks carnivorous plants use to lure their treats, meet servals and ocelots from Bonnie Cromwell's Classroom Safari, and become a connoisseur of camouflage—animal and otherwise.”

Information on tickets and parking and other data on the Exploratorium Pier 15 website

A walking stick is expected to be one of the Bohart Museum of Entomology attractions at Exploratorium Pier 15 on Oct. 2. (Photo by Kathy Keatley Garvey)
A walking stick is expected to be one of the Bohart Museum of Entomology attractions at Exploratorium Pier 15 on Oct. 2. (Photo by Kathy Keatley Garvey)

A walking stick is expected to be one of the Bohart Museum of Entomology attractions at Exploratorium Pier 15 on Oct. 2. (Photo by Kathy Keatley Garvey)

UC Davis entomology graduate student Ralph Washington (right) chats with UC Davis assistant professor/bee biologist Brian Johnson at the Bohart Museum open house on Sept. 27. (Photo by Kathy Keatley Garvey)
UC Davis entomology graduate student Ralph Washington (right) chats with UC Davis assistant professor/bee biologist Brian Johnson at the Bohart Museum open house on Sept. 27. (Photo by Kathy Keatley Garvey)

UC Davis entomology graduate student Ralph Washington (right) chats with UC Davis assistant professor/bee biologist Brian Johnson at the Bohart Museum open house on Sept. 27. (Photo by Kathy Keatley Garvey)

Posted on Monday, September 29, 2014 at 6:04 PM

4-H teaches responsibility

The October issue of Central Valley magazine.
Fresno County 4-H member Tanner Rosales and his goat Bonnie graced the cover of October's Central Valley magazine as time for showing the animal at the Big Fresno Fair approaches.

Tanner, 10, hails from a family with a long 4-H tradition. Mom Kellie Rosales started in 4-H at age 9. Grandma Teri Penfold grew up in 4-H and is now a leader.

With more than 6 million members, 4-H is the nation's largest youth development organization, supporting students ages 9 to 19 through an expansive and varied program designed to shape future leaders and innovators, the article said.

In California, 4-H is part of UC Cooperative Extension.

The article described the months-long process Tanner has undertaken to show a farm animal at the fair. He meets weekly with the 4-H goat leader and makes one or two additional trips to work with Bonnie on his own.

4-H members are responsible for regularly walking their animals, feeding them, weekly weigh-ins, giving any oral medications, practicing showing in a ring and touching the animals so they're used to being handled.

"The 4-H program teaches the commitment needed to properly prepare a goat for show - and more importantly - how to see a project through to completion," the article said.

Rosales said she appreciated the opportunities and experiences that 4-H provided.

"I just want that for my kids," she said. "I want them to know they're going to work hard, and when they work hard it's going to pay off."

Posted on Monday, September 29, 2014 at 8:49 AM

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