- Author: Kathy Keatley Garvey
Take the immature form (caterpillar) of the moth, Schizura concinna, family Notodontidae. We first spotted this caterpillar on our Western redbud tree (Cercis occidentalis) in September 2010.
It has a red hump. The common name: The redhumped caterpillar.
Art Shapiro, distinguished professor of evolution and ecology at UC Davis, told us that the red hump contains a defensive formic acid gland. "They hold their anal prolegs, which are not useful for walking, in the air and thrash their rear ends in unison when disturbed. This is the ONLY defoliator of redbud around here, and is very common. It also attacks walnut and a variety of other chemically-distinctive trees that other things don't eat, as a rule."
We wondered if these little thrashing visitors should concern us. "The damage is minor, and I strongly advise against spraying; hand-picking can be used if control is deemed necessary, but they feed so late in the season that there is no actual harm to the tree," he told us. "The moth is very nondescript. It holds its wings wrapped around the body cylindrically and looks remarkably like a cigarette butt, though it is probably 'imitating' a broken-off twig. Despite authoritative commentary to the contrary, they have two broods a year here but are usually seen in fall. The species is native on both coasts and oddly absent in most of the mid-continent."
We thought we might see redhumped caterpillars on our liquidambar (sweet gum) trees that we planted more than two decades ago. We never have.
What we did see this week is that the UC Statewide Integrated Pest Management Program (UC IPM) has revised its Pest Notes: Redhumped Caterpillar. A recent UC IPM blog described the caterpillar as a "familiar pest on fruit and nut trees such as plum, almond, cherry, and apple, as well as on ornamental trees like liquidambar and birch. It can reach high populations in California's Central Valley, sometimes defoliating entire trees."
The Pest Note, co-authored by entomologists Emily Symmes, UC IPM and UC Cooperative Extension, Sacramento Valley, and Steve Dreistadt, UC IPM, describes the pest, its life cycle, and the damage rendered. You can read about a variety of management techniques.
Ah, the redhumped caterpillar...
And if you're curious about common names and scientific names of insects, the Entomological Society of America (ESA) maintains a Common Name Database, "an essential reference for anyone who works with insects. It includes more than 2,000 common names and is searchable by common name, scientific name, author, order, family, genus, and species."
Have a suggestion for a common name? You can propose it on the ESA form. Names are reviewed by the Committee on the Common Names of Insects and voted on by the ESA Governing Board.
It's probably unlikely, however, that redhumped caterpillar, will undergo a name change any time soon. That red hump is so descriptive!
- Author: Kathy Keatley Garvey
That incongruous belief that “Honey is bee vomit” is resurfacing on a number of YouTube channels, opinion pieces and other Internet posts. It's usually said with great glee: “Honey is bee vomit! It's bee puke! It's bee barf!”
Is it #FakeNews?
We asked noted honey bee guru Eric Mussen, Extension apiculturist emeritus at the University of California, Davis, whose career in bee education spans four decades, to settle the issue. Although he retired in 2014, he keeps active. Last year he completed a term--his sixth--as president of the Western Apicultural Society. He maintains an office in Briggs Hall.
And he continues to answer questions about bees and honey.
“As for the bees and vomit issue, the explanation requires quite a bit of knowledge,” Mussen says. It's about an "expandable pouch called 'the honey stomach' (which we humans do not have) and a valve called the "proventriculus" (which we humans do not have)."
“As most people know, honey begins as a dilute sugar solution secreted by ‘nectaries,' sugar syrup-secreting glands which are located in flowers or in extra-floral nectaries,” Mussen explains. “Pollen is not a natural constituent of nectar. The nectar is sucked up by honey bees and it passes into an expandable pouch called the ‘honey stomach.' This is the pre-digestive part of the part of the digestive tract that honey bees use to bring water and nectar to the hive. In honey bees and other insects, this ‘crop' precedes the portions of the digestive tract used for digesting food. There is a unique valve between the crop and the ventriculus (midgut), called the ‘proventriculus,' that has rake-like projections that constantly pull particulates, like pollen grains, from the crop contents and push them along for digestion.”
“Then the film is again exposed to the air. That process repeats itself until the moisture content of the syrup falls below 20 percent. Evaporation is influenced significantly by the relative humidity. Since honey will ferment at moisture contents above 20 percent, it is important to leave the honey with the bees until it can be immediately processed in locations with high humidity. That honey will seem to be thin. During the summer in California, the ambient relative humidity is quite low--15 percent or less. In that case, honey produced in the Central Valley can have a moisture content of 13 to 13.5 percent. That honey is quite thick.”
As an aside, “pollen grains are likely to be found in honey,” Mussen says. “Wind-blown pollens can fall into flowers that are open faced. Pollen grains are collected by hairs on the bees' bodies. They can get onto the mouthparts and become consumed with the nectar. Nectar-processing bees may have eaten some pollen in the hive before processing the honey. This is how the pollen grains get into honey. They do not necessarily get consumed with the fresh nectar. Physical contaminants of honey have to be quite small, like pollen grains, since the bees ingest all their food by drinking it through a straw-like proboscis with a very small opening at the tip. Most of the physical contaminants are removed by the proventriculus.”
And here's the point: “Since honey never is mixed with digesting food in the intestinal tract, it is inaccurate to refer to honey as ‘bee vomit.' A dictionary definition of vomit includes ‘disgorging the stomach contents through the mouth.' Since a human does not have a crop, the stomach is in direct contact with the esophagus and mouth. In a bee, the proventriculus and crop are in direct contact with the mouth. The digestion of solid foods in bees begins in the ventriculus and there is no way that a honey bee can bring that food back through the proventriculus, or ‘vomit.'
Which begs the question: Why can't we enjoy honey for what it is, not for what it isn't?
We can. Mark your calendar to attend these two events: the second annual California Honey Festival on May 5 in downtown Woodland (it's held in partnership with the UC Davis Honey and Pollination Center) and the fourth annual UC Davis Bee Symposium: Keeping Bees Healthy (hosted by the Honey and Pollination Center and the UC Davis Department of Entomology and Nematology) on March 3 in the UC Davis Conference Center. The Bee Symposium will feature keynote speaker Thomas Seeley, the Horace White Professor in Biology at Cornell University, New York.
Interested in beekeeping? UC Davis Extension apiculturist Elina Lastro Niño and her lab will teach a number of classes this spring, beginning March 24, at the Harry H.Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, UC Davis campus.
The schedule and links to the capsule information:
- Planning Ahead for Your First Hives: Saturday, March 24
- Working Your Colonies: Sunday, March 25
- Queen-Rearing Techniques Short Course: Saturday and Sunday, April 21-22 course; Saturday and Sunday, April 28-29 course
- Bee-Breeding Basics: Saturday, June 9
- Varroa Management Strategies: Saturday, June 16
- Author: Kathy Keatley Garvey
Travelers know Iquitos as the "capital of the Peruvian Amazon" but scientists know it as a hot spot for dengue, a mosquito-borne viral disease with raging outbreaks in many tropical and subtropical countries.
Amy Morrison, stationed in Iquitos full-time, has directed dengue research activities there for the past 15 years. An epidemiologist who joined the UC Davis laboratory of medical entomologist Thomas Scott (now professor emeritus) in 1996, she's a project scientist and scientific director of the Naval Medical Research Unit No. 6 (NAMRU-6) Iquitos Laboratory.
Morrison is back in the states to present a UC Davis seminar on "Targeting Aedes Aegypti Adults for Dengue Control: Infection Experiments and Vector Control in Iquitos" from 4:10 to 5 p.m., Wednesday, Jan. 10, in 122 Briggs Hall, Kleiber Hall Drive.
Hosted by the UC Davis Department of Entomology and Nematology, it's the first in a series of winter seminars coordinated by assistant professor Rachel Vannette and Ph.D student Brendon Boudinot of the Phil Ward lab.
Dengue is a threat to global health, says Morrison, who holds a doctorate in epidemiology from Yale University and a master's degree in public health from UCLA. According to the World Health Organization (WHO), the incidence of dengue has increased 30-fold over the last 50 years and almost half of the world population is now at risk. It's ranked as "the most critical mosquito-borne viral disease in the world."
"Each year, an estimated 390 million dengue infections occur around the world," according to the World Mosquito Program. "Of these, 500,000 cases develop into dengue hemorrhagic fever, a more severe form of the disease, which results in up to 25,000 deaths annually worldwide."
Of the dengue project in Iquitos, Morrison says: "Comprehensive, longitudinal field studies that monitor both disease and vector populations for dengue viruses have been carried out since 1999 in Iquitos. In addition, to five large scale-vector control intervention trials, ongoing data collection has allowed the evaluation of Ministry of Health emergency vector control using indoor ULV space sprays with pyrethroids in concert with larviciding through multiple campaigns, as well as characterize local DENV (dengue virus) transmission dynamics through two and one novel DENV serotype and strain invasions into the city."
"Our research group has also been conducting contact cluster investigations on DENV-infected and febrile control individuals since 2008," Morrison relates. "These studies demonstrated that attack rates were consistent between houses where cases were first detected and recently visited contact houses independent of distance between these locations. Furthermore, contact cluster investigations allow us to identify viremic individuals across the spectrum of disease outcomes including inapparent infections."
"Using DENV positive individuals captured through these and other febrile surveillance protocols, we exposed laboratory reared (F2) Aedes aegypti mosquitoes directly on their arms or legs, and obtained blood samples with and without EDTA for exposure of mosquitoes in an artificial membrane feeder. After a 58-participant pilot study comparing feeding methods, we initiated a direct feeding protocol exposing participants (78 feeds in 31 participants to date). Feeding, survival, midgut infection and systemic dissemination are all higher using direct feeding than indirect feeding methods. Of 22 participants without detectable fluorescent focus assay titers in their serum at the time they were exposed to mosquitoes, 14 infected mosquitoes by at least one method."
"Although virus titer was a predictor of mosquito infection, mosquitoes became infected at low or undetectable titers and with subjects experiencing mild disease. We have evaluated insecticide-treated curtains and a novel lethal ovitrap (Attractive Lethal OviTrap = ALOT) for dengue control. Only the ALOT traps showed a significant impact on dengue incidence corresponding to a modest decrease in vector densities and a shift of the mosquito population age structure in the trap area to younger mosquitoes. Recent evaluations of indoor ULV interventions with pyrethroids suggest that ULV campaigns that reduce Aedes aegypti for at least 3 weeks through multiple fumigation cycles can mitigate DENV transmission during the same season."
Bottom line: "We argue that Aedes aegypti control should focus on interrupting transmission rather than long-term suppression at operationally unachievable levels and that emergency control should be applied at area-wide scales rather than reacting to individual DENV cases."
- Author: Kathy Keatley Garvey
When the American Beekeeping Federation (ABF) meets Jan. 9-13 at the Grand Sierra Resort, Reno, Nev. for its 75th annual American Beekeeping Federation Conference & Tradeshow, the key concern is bee health.
Sadly, colony losses continue to take their toll.
Our nation's honey bee colonies are down slightly for operations with five or more colonies, according to statistics released Aug. 1, 2017 by the U.S. Department of Agriculture (USDA).
In its news release, the USDA's National Agricultural Statistics Service noted that "Honey bee colonies for operations with five or more colonies in the United States on January 1, 2017 totaled 2.62 million colonies, down slightly from January 1, 2016. The number of colonies in the United States on April 1, 2017 was 2.89 million colonies. During 2016, honey bee colonies on January 1, April 1, July 1, and October 1 were 2.62 million, 2.80 million, 3.18 million, and 3.03 million colonies, respectively."
Honey bee colony loss (for operations with five or more colonies) amounted to 362,000 colonies or 14 percent. "The number of colonies lost during the quarter of April through June 2017 was 226,000 colonies, or 8 percent," according to the USDA news release. "During the quarter of October through December 2016, colonies lost totaled 502,000 colonies, or 17 percent, the highest of any quarter in 2016. The quarter in 2016 with the lowest number of colonies lost was April through June, with 330,000 colonies lost, or 12 percent."
And again, no surprise: the No. 1 colony stressor was that dreaded varroa mite (Varroa destructor) and the viruses it can transmit. The parasitic mites suck the blood (hemolymph) from both the adults and developing brood, especially drone pupae.
The ABF conference will zero in on the varroa mite at several presentations on Thursday, Jan. 10:
- "Selecting for Behavioral Resistance to Varroa Destructor"--Krispn Given, Apiculture Specialist, Purdue University Department of Entomology, West Lafayette, Ind.
- "RNA Viruses and Varroa Mites: Temporal Variation in Honey Bee Pathogens Influences Patterns of Co-Infection"--Alex Burham, University of Vermont, Burllngton, Va.
- "Engaging Beekeepers with MiteCheck: Implementing a Nationwide Citizen Science Program for Monitoring and Comparing Varroa destructor Infestations"--Rebecca Masterman, University of Minnesota, St. Paul, Minn.
Overall, the diamond-anniversary conference will focus on educational sessions, social and networking activities "and lots of opportunities to learn about new products and services," according to ABF president Gene Brandi of Los Banos, a bee industry leader for four decades. He currently manages some 2000 colonies in central California with his son.
Morris Weaver of Montgomery, Texas, the 1975-76 ABF president, will deliver the keynote presentation on "The American Beekeeping Federation, Inc.: 75 Years Strong."
Attendees can choose from five track sessions: small scale beekeepers; serious sideliners; package bee and queen breeders; honey producers and packers; and commercial beekeepers. Registration also will take place at the door.
On Saturday, Jan. 13, Amina Harris, director of the UC Davis Honey and Pollination Center, will present two honey-tasting workshops: "Taste and Evaluate Honey: Matching Flowers to Flavors."
This week is truly a gathering of bee scientists and beekeepers. In conjunction with the ABF conference, the American Bee Research Conference will take place Jan. 11-12 in Reno. Marla Spivak, MacArthur Fellow and Distinguished McKnight University Professor, University of Minnesota, is the keynote speaker.
- Author: Kathy Keatley Garvey
Not environmental artist Ann Savageau; the retired UC Davis Department of Design professor creates art from hornet nest paper.
"I began using hornet nest paper back in Ann Arbor, Mich. in the early 1990s," said Savageau, who describes herself as "an environmental artist who creates mixed-media sculpture and installations."
"Hornet's nests are common in that area," she said. "I am attracted to the beautiful colors and patterns."
Her art will be among works displayed at the UC Davis Design Museum's exhibition, It's Bugged: Insects' Role in Design, set Jan. 8-April 22 in Room 124 of Cruess Hall. The show is open to the public from noon to 4 p.m. weekdays and from 2 to 4 p.m. on Sundays. Admission is free.
The professor emerita, a member of the UC Davis faculty from 2003 to 2014 and now a full-time artist, says her work deals with the natural world, human culture, and their intersection. "My current interests include global warming and environmental destruction; consumer culture and wasteful consumption; and artistic transformations of waste." Her Stanford anthropological training, her interest in the natural world, and the many places she has lived are reflected in her art, which she has displayed in more than 80 exhibitions, both nationally and internationally.
For the UC Davis exhibition, Savageau created a trilogy of wall pieces made from hornets' nest paper, and a set of sculptures made of wood etched into striking patterns by bark beetle larvae.
Savageau said she collected only unoccupied hornet nests in the Ann Arbor area, which she found on tree branches or lower in bushes. She has never been stung. "I collected the nests in late fall or winter, after some hard frosts, when the nests were empty (no life inside)," she said. "The queen leaves the nest and hibernates, under a log or some other protected place."
The nests she's collected range in size from a basketball to 30 inches in diameter.
The artistic process? "The paper on the nest is many layers deep," Savageau related. "I peel the paper off the nest—it comes off in irregular sizes and shapes. Then I collage it onto foam core, matching the irregular pieces in such a way that they appear to be one large sheet. The pieces are usually no larger than four to six inches. It's similar to piecing together a jigsaw puzzle."
The artist, who holds a bachelor's degree from Stanford University and her master's degree in fine arts from Wayne State University, Detroit, taught at the University of Michigan Residential College, Ann Arbor, from 1978-2002 before joining the UC Davis faculty in 2003. (See more of her work at http://annsavageau.com/)
"The colors and patterns of a hornet's nest are indeed exquisite," said Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis. "We have several hornet nests as part of our museum's collection, and one is huge--larger than a basketball." The bald-faced hornet, Dolichoves pulamaculata, crafts the papery, egg-shaped nests by mixing wood fibers with saliva. The insect's name refers to the ivory-white markings on its face. Its thorax, legs and abdomen also have white markings.
The hornet nest closes down in late fall or winter, Kimsey said, and the queen leaves to hibernate for the winter in such protected places as in hollow trees and fence posts, or under logs, bark or rock piles. In the spring, the queen emerges to begin building a nest, which eventually may contain some 400 to 700 workers. The nests are mottled gray with layered hexagonal combs.
The bald-faced hornets are considered important to the ecosystem in that they pollinate plants and prey upon many insect pests. They are, however, known for their highly defensive behavior in protecting their nests.
A reception heralding the opening of the Design Museum exhibition is set from 6 to 8 p.m., Thursday, Jan. 11. Savageau will give a presentation on the exhibition at 6:30 p.m. in Room 256 of Cruess Hall.
(Visit the Design Museum for map and parking information.)
