- Author: Kathy Keatley Garvey
So says ecologist Richard 'Rick' Karban, professor of entomology, UC Davis Department of Entomology and Nematology, and author of the newly published book, Plant Sensing and Communication (University of Chicago Press).
Over the past several years, we've heard Karban speak about plant communication at UC Davis and beyond. His talks always draw an enthusiastic crowd.
Whenever I see Gulf Fritillary caterpillars chewing on our passionflower vine (yes, we planted the vine for the butterflies), I wonder what the plant is sensing with all that crunching, munching and chomping going on. Sometimes a scrub jay will swoop down and grab a beakful of caterpillars. Sometimes a praying mantis or European paper wasp will target the 'cats. Sometimes I feel sorry for the passionflower vine--especially after the 'cats have defoliated it, leaving only scarred stems.
It's a battlefield out there, and so fascinating.
So we asked Karban "What are 10 things to know about plant sensing and communication?"
Here's the list:
- Plants sense their environments and respond.
- Although they lack central nervous systems, they process information and appear to "behave intelligently."
- They sense the position of competitors and "forage" for light.
- They sense the availability of water and nutrients in the soil and "forage" for these resources.
- Their decisions are influenced by past experiences, akin to memory.
- The respond to reliable cues that predict future events, allowing them to "anticipate."
- Plants respond differently to cues that they themselves produce, allowing them to distinguish self from non-self.
- They respond differently to close relatives and strangers.
- Plants that are prevented from sensing or responding experience reduced fitness.
- By understanding the "language" of plant responses, we can grow healthier and more productive plants.
The 240-page book is a “landmark in its field,” said Graeme Ruxton of the University of St. Andrews, UK, co-author of Experimental Design for the Life Sciences and Plant-Animal Communication.
“Karban seeks to argue that plants behave—that they sense their environment, detect and communicate with an array of different organisms, and respond to their sense of the environment and communication,” Ruxton said. ”He is very successful in this, demonstrating that plant sensing and communication is a vibrant area of current research with still plenty more to discover.”
The book is “the first comprehensive overview of what is known about how plants perceive their environments, communicate those perceptions, and learn,” according to the publisher. “Facing many of the same challenges as animals, plants have developed many similar capabilities: they sense light, chemicals, mechanical stimulation, temperature, electricity, and sound. Moreover, prior experiences have lasting impacts on sensitivity and response to cues; plants, in essence, have memory."
Karban has researched plant communication in sagebrush (Artemisia tridentata) on the east side of the Sierra since 1995. His groundbreaking research on plant communication among kin, published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences, drew international attention. In that study, Karban and his co-researchers found that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors.”
“Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote.
In other words, if you're a sagebrush and your nearby kin is being eaten by a grasshopper, deer, jackrabbit, caterpillar or other predator, communication is more effective if you're closely related. Through volatile cues, your kin will inform you of the danger so you can adjust your defenses.
Karban likened this kind of plant communication to eavesdropping.” Plants “hear” the volatile cues of their neighbors as predators damage them.
Karban is featured in the Dec. 23-30, 2013 edition of The New Yorker in Michael Pollan's piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants."
- Author: Kathy Keatley Garvey
So you want to be a beekeeper...but you don't know where to begin.
You're in luck.
Bee experts at the Harry H. Laidlaw Jr. Honey Bee Research Facility, University of California, Davis, are planning two short courses or sessions in September--the first on Sept. 13 and the second on Sept. 20.
This will be their inaugural "Planning Ahead for Your First Hives," taught by Extension apiculturist Elina Niño and staff research associate Bernardo Niño at the Laidlaw facility, located on Bee Biology Road, west of the central campus. Each course will be limited to 24 participants and registration is now underway.
"The short course will include lectures and hands-on exercises," they announced. "This course is perfect for those who have little or no beekeeping experience and would like to obtain more knowledge and practical skills to move on to the next step of owning and caring for their own honey bee colonies."
Lecture modules will cover honey bee biology, beekeeping equipment, how to start your colony and maladies of the hive. The practical modules will cover how to build a hive, how to install a package, how to inspect your hive and how to monitor for varroa mites.
"Participants will have the opportunity to learn about and practice many aspects of what is necessary to get the colony started and keep it healthy and thriving," they said. "At the end of the course, participants will be knowledgeable about installing honey bee packages, monitoring their own colonies and possible challenges with maintaining a healthy colony."
This is a BYOV (that's Bring Your Own Veil--if you own one. If you don't, they have some on hand.) The $95 registration fee covers the cost of the course materials (including a hive tool), lunch and refreshments. For more information, contact Bernardo Niño at elninobeelab@gmail.com or call the lab at 530-380-2899.
Be sure to check on Elina Niño's monthly newsletter, from the UC Apiaries and the Niño lab's Facebook page.
- Author: Kathy Keatley Garvey
Sometimes you just can't win for losing.
This morning a newly emerged Gulf Fritillary butterfly (Agraulis vanillae) began drying its damp wings, preparing for flight. It had just emerged from its chrysalis. Soon it would be off to do what Gulf Frits do: leave its host plant, the passionflower vine, and find a mate.
It was not to be.
A cunning praying mantis, camouflaged as a green stem, snared it, grasping it in its spiked forelegs. Then it did one praying mantids do. It bit off its head and proceeded to eat it.
Quick and easy prey, for sure. But the mantis was not alone. A European paper wasp, seeking a little free protein to take back to her colony, got into the act, circling the struggling butterfly and taking quick bites.
The wasp carefully evaded the mantid's head and spiked forelegs.
If it it had not, this it would have been a two-course dinner. Butterfly first, wasp second.
Mouse Productions filmed a battle between a praying mantis and a wasp back in 2013. The mantis won. See YouTube video.
- Author: Kathy Keatley Garvey
Talk about a spittin' image.
When you see one spittlebug froth, you've seen them all, right? They all look alike, right?
Well, the froth does, but you'll see different shapes and sizes on your plants.
When Ria de Grassi, director of Federal Policy, California Farm Bureau Federation, recently asked us a question about her encounter with spittlebug froth, our bee guy, Extension apiculturist emeritus Eric Mussen of the UC DAvis Department of Entomology and Nematology, answered it.
"Yes," he told Ria, "it is the bee guy answering questions on spittle bugs."
Mussen, who retired last year after 38 years of service, knows a lot about bees. Hey, he's an apiculturist. But he also knows a lot about spittle bugs. Hey, he holds a doctorate in entomology.
We thought we'd share the information.
"Just like foraging bees, spittlebugs have favorite host plants," Mussen says. "And just like bees, when the favorite plant is missing or drying up, the spittlebugs move to 'Plant B.' Actually, the nymph in the spittle cannot change plants, Momma has to lay eggs on the new selection."
"They normally start on weeds and they will stay there if the weeds hang around. Nothing is hanging around like they used to when they had some some soil moisture into the summer. So, the spittlebugs have moved into irrigated landscapes."
"I do not believe that spittlebugs vector plant diseases or cause physiological damage to their host plants. They are just an eyesore. The nymphs need the spittle to keep them moist, since they are very prone to dehydration. Using a jet of water, you can wash off the spittle. The bug usually goes with it. I don't know if their sucking mouthparts get broken or not (depends on whether or not the bug stays attached and feeding all the time). Thus, I don't know if they are physically capable of going back to business after being washed off."
"While they are out of the spittle, they are very likely to dehydrate to death in our climate, so wash them off in the morning and let them roast during the day."
Mussen says there's a group of systemic insecticides that might kill them on whatever plant is treated, "but those insecticides may not be too pollinator friendly if the plant is likely to come into bloom after the treatment."
We've often heard "spittlebugs" shortened to "spit bugs." A quick and easy and descriptive term.
The UC Statewide Integrated Pest Management Program (UC IPM) says that spittlebugs occur throughout the United States "and can at least occasionally be found on almost any plant. Adult spittlebugs are inconspicuous, often greenish or brownish insects, about 0.25 inch long. Immature spittlebugs are recognized by the frothy white mass that nymphs surround themselves with on plant tissue where they feed."
What spittlebugs do is suck plant juices. And, as UC IPM says, "heavy infestations distort plant tissue and slow plant growth. The obvious and occasionally abundant masses of white foam on cones, foliage, or stems may be annoying, but the spittlebugs do not seriously harm established woody plants."
- Author: Kathy Keatley Garvey
So, what's a meloid beetle to do?
Here you are, a meloid beetle foraging on a Mexican sunflower (Tithonia) and these long-horned digger bees keep dive-bombing you and pestering you.
Then a Gulf Fritilllary butterfly (Agraulis vanillae) decides it wants a share of your flower.
So, it's take to take flight!
Blister beetles (family Meloidae) are known throughout the insect world for their defensive secretion of a blistering agent, cantharidin, according to Wikipedia. "About 7,500 species are known worldwide. Many are conspicuous and some are aposematically colored, announcing their toxicity to would-be predators."
Don't touch a blister beetle because that poisonous chemical can blister your skin.
Did you know that cantharidin is the principal irritant in Spanish fly, a folk medicine prepared from dried beetles in the Meloidae family? Wikipedia tells us so.
The UC Statewide Integrated Pest Management Program (UC IPM) offers information about blister beetles in a UC Pest Management Guideline on its website. "Blister beetles are narrow and elongate and the covering over the wings is soft and flexible. They may be solid colored (black or gray) or striped (usually orange or yellow and black) and are among the largest beetles likely to be found in a sweep net sample in alfalfa."
UC IPM points out that cantharidin is toxic to livestock. "Cantharidin is contained in the hemolymph (blood) of the beetles and may contaminate forage directly when beetles killed during harvest are incorporated into baled hay or indirectly by transfer of the hemolymph from crushed beetles onto forage. As the name implies, handling these insects may result in blisters, similar to a burn, on the hands or fingers. Blister beetles have been a serious problem in alfalfa in the northern United States, the Midwest, and the south for many years, but until recently have not been a problem in California."
Blister beetles have been linked to the death of several dairy cows in the southern Owens Valley, according to UC IPM. "At this point, it is not known if blister beetles are widespread or confined to the Owens Valley. Likewise, it is not known if the problem is likely to spread and hence become a common occurrence in California alfalfa. In the meantime, growers and PCAs (Pest Control Advisors) are advised to be on the lookout for blister beetles and to contact their farm advisor for advice if these insects are found."
