Backyard Orchard News
That quote sound familiar? Chemical ecologist Jacques Le Magnen (1916-2002) said that back in 1970.
World-renowned organic chemist Wittko Francke (right) of the University of Hamburg, Germany, called attention to Le Magnen's quote at a UC Davis Department of Entomology seminar on Wednesday noon, Dec. 8.
It bears repeating: "Nature is more a world of scents than a source of noise."
Insects communicate in a chemical language or chemical signals, Francke told the crowd.
Indeed, scientists have long known that methods that can attract or repel insects have important applications for agricultural pests and medical entomology.
Francke told how a queen bee secretes compounds that regulate development and behavior of the colony, and how an orchid releases the scent of a female wasp to attract male wasps— a scent that results in pollination. He also touched on the “calling cards” of a number of other insects, including bumble bees, wasps, pea gall midges, stingless bees, bark beetles and leafminers. He pointed out that that plants, too, send chemical signals.
UC Davis graduate students James Harwood and Amy Morice of the James R. Carey lab video-taped the seminar. It will be online soon at http://entomology.ucdavis.edu/news/webcastlinks.html
Francke was introduced by chemical ecologist-forest entomologist (and UC Davis Department of Entomology affiliate) Steve Seybold of the USDA Forest Service, Pacific Southwest Research Station, Davis.
No stranger to UC Davis, Francke previously collaborated with chemical ecologist Walter Leal, professor and former chair of the UC Davis Department of Entomology, on attractants for navel orangeworm.
In his talk, Francke mentioned Leal’s discovery of a sophisticated mechanism for the isolation of the chemical communication channels of two species of scarab beetles.
Seybold and Francke are collaborating on the chemical signals of the walnut twig beetle, which in association with a newly described fungus, causes thousand cankers disease, a killer of walnut trees.
Thousand cankers disease (TCD) is now found in seven western states, plus Tennessee. Seybold is a key researcher in California.
Scientists believe that TCD occurs only on walnut, predominantly native black walnut, Juglans californica and J. hindsii, although the disease has been recorded on 10 species of walnuts or their hybrids in California.
Often the first symptoms of TCD are flagging and yellowing leaves and branch dieback, said Seybold, who has been studying the chemical ecology and behavior of bark beetles for more than 25 years. Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus.
A USDA/UC Davis research team is tracking the pathogen and the beetle throughout California, particularly in commercial orchards.
That all points back to “Nature is more a world of scents than a source of noise.”
They Deal with Scents
Those malaria mosquitoes may have met their match--with researchers at the University of California, Davis.
UC Davis entomology doctoral candidate Ashley Horton, recent winner of the 2010 Arthur J. and Dorothy D. Palm Agricultural Scholarship, focuses her research on how mosquitoes transmit malaria.
Horton studies with major professor Shirley Luckhart, professor in the Department of Medical Microbiology and Immunology and researches how the immune system of the malaria mosquito, Anopheles gambiae, affects the transmission of the Plasmodium parasite, the causative agent of malaria.
Malaria kills more than a million people a year, primarily in Africa.
“Ashley’s work that was recently published in Malaria Journal, together with our co-authors and collaborators Dr. Yoosook Lee and Dr. Gregory Lanzaro, is the first to identify mutations in immune signaling genes that exhibit associations with natural infection with Plasmodium falciparum in field-collected Anopheles gambiae mosquitoes in Mali," Luckhart said. "Plasmodium falciparum is the most important human malaria parasite in Africa and this work is necessary as a foundation to assess whether genetic control measures to block transmission of this parasite will be possible in malaria-endemic countries.”
The research, titled "Identification of Three Single Nucleotide Polymorphisms in Anopheles gambiae Immune Signaling Genes that are Associated with Natural Plasmodium falciparum Infection," appears in the June 10, 2010 edition of Malaria Journal.
Horton, who received her bachelor's degree in public health studies at The Johns Hopkins University, Baltimore, joined the UC Davis Entomology Graduate Program in 2005. In 2008 she received a William Hazeltine Student Research Fellowship, an award in memory of a noted California entomologist.
The Palm scholarship supplements her fellowship support from a National Institutes of Health T32 training grant that is managed by director Lanzaro and associate director Luckhart.
Arthur Palm, an alumnus of UC Davis, received his bachelor's degree in agricultural economics in 1939. He and his wife established the endowed fund to support undergraduate and graduate students.
The Palm family and others who fund scholarships not only support our university students; they support public health issues.
They, too, are tackling malaria.
Close-up of malaria mosquito
Honey bee guru Eric Mussen, Extension apiculturist and a member of the UC Davis Department of Entomology faculty, is quoted in a Dec. 6 article in the Epoch Times about colony collapse disorder (CCD).
CCD is the mysterious phenomenon characterized by adult bees abandoning the hive, leaving behind the queen bee, brood, and food stores.
The gist of the Epoch Times article: The European Commission recently published its concerns about honey bee health.
In a communiqué, the commission sought to clarify the key issues related to bee health and key actions that it intends to take to address them.
"Beekeeping is a widely-developed activity in the European Union (EU), both at professional (keepers with over 150 hives) and hobby level," the communiqué began. "There are around 700,000 beekeepers in the EU out of which around 97% are non-professional accounting for around 67% of EU hives. Honey production is estimated to be close to 200,000 tons. Beekeeping is also associated with the production of other products such as wax, royal jelly, propolis, etc."
Epoch Times reporter Marco 't Hoen subsequently sought out Mussen for information on CCD and honey bee health in the United States. Mussen told him that CCD is a worldwide problem.
Twenty-five percent of beekeepers in the United States have recurring problems with CCD, Mussen said. The colonies range in size from one to 15,000.
Wrote the reporter: "He (Mussen) believes that in the U.S., CCD is caused by an infectious disease, which they have not yet identified. His reasoning is based on the fact that when bees are introduced to replace the dead one, they die as well. But when the hive is cleaned properly the new bees can survive."
Indeed, CCD is linked to multiple causes, including diseases, pests, pesticides, malnutrition and stress. Weakened colonies don't fare well.
The Epoch Times article quoted USDA statistics indicating that bee pollination of crops "is worth $15 billion per year" in the United States. For example, "the almond industry in California alone used about half of the 2.3 million colonies in the country in 2009 for pollination." In the European Union, about 700,000 beekeepers maintain almost 14 million colonies, according to the EC communiqué.
As an aside, U.S. beekeepers are now gearing up for the California almond season, which usually starts around Feb. 1. The state has more than 700,000 acres of almonds and each acre requires two hives for pollination. Since California doesn't have that many bees, bees are trucked here from all over the country.
It's a gold rush of sorts in the Golden State.
California, here we come!
There's an "alarming resurgence in the population of bedbugs" in the United States, according to the Centers for Disease Control and Prevention (CDC).
The exact cause is not known, but the CDC says it could be linked to "increased resistance of bed bugs to available pesticides, greater international and domestic travel, lack of knowledge regarding control of bed bugs due to their prolonged absence, and the continuing decline or elimination of effective vector/pest control programs at state and local public health agencies."
The Los Angeles Times warned in a Dec. 4 headline: L. A.'s Slow Trickle of Bedbugs May Turn Into a Flood.
That's a big "bah-humbug" for the holidays.
Senior museum scientist Steve Heydon of the Bohart Museum of Entomology, UC Davis, was quoted as saying:
Remember the exciting news article published in November of 2009 in Science Daily about how an orchid species on the Chinese island of Hainan "fools its hornet pollinator by issuing a chemical that honey bees use to send an alarm?"
The research was first published in Current Biology, a Cell Press publication.
"The discovery explains why the hornets, which capture honey bees to serve as food for their larvae, have been observed to literally pounce on the rewardless Dendrobium sinense flowers," the Science Daily author wrote.
Can you imagine? Hornets "detect" one of their favorite foods--honey bees--and they pounce on the flower and come up empty-handed or "empty-mouthed?"
The orchids produce a deceptive chemical, a compound called Z-11-eicosen-1-ol, described as "a rarity even in the insect world."
One of the researchers involved in this study--and hundreds of other insect communication studies--is world-renowned chemical ecologist Wittko Francke (top photo) of the University of Hamburg, Germany.
And now he's coming to the University of California, Davis, to present a seminar.
Francke will speak on "Insect Semiochemicals: Structural Principles and Evolution" at a UC Davis Department of Entomology seminar on Wednesday, Dec. 8 from 12:10 to 1 p.m. in 122 Briggs Hall, off Kleiber Hall Drive. He'll be introduced by host and fellow chemical ecologist Steve Seybold of the USDA Forest Service, Pacific Southwest Research Station, Davis, and an affiliate of the UC Davis Department of Entomology."Professor Francke has been a driving force in the field of chemical ecology for the last four decades, discovering countless new natural product chemicals of behavioral significance for animals and helping us to understand how plants and animals interact," said Seybold (left).
"Nearly everyone in the field has collaborated with him at some level; he has been a consummate mentor to younger chemical ecologists and has always been generous with his time, intellect, and chemical skills to everyone in that community," Seybold said. "He is remarkably brilliant in that he sees patterns in the make-up and synthesis of bio-organic compounds that most biologists, and even many chemists, may overlook."