Posts Tagged: Xerces Society
The western migration of the Monarch butterflies (Danaus plexippus) to their overwintering sites along the California coast is underway.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, recorded four Monarchs at his Suisun monitoring site yesterday. He's been monitoring butterflies in Central California for some four decades.
This morning, a male Monarch fluttered into our yard to sip some nectar from a Mexican sunflower (Tithonia). (A distinguishing feature of the male Monarch: a small black spot on each of its two hindwings. See photo below.)
Monarchs head for sites along the coast, including Santa Cruz, Monterey, Natural Bridges and Pacific Grove, to overwinter, Shapiro noted.
"There used to be a small site in Fairfield, near the old Juvenile Hall on West Texas Street, in a row of Eucalyptus. It's been gone for decades. Some years they try to overwinter in Marin and Sonoma counties, but usually give up and shift south in December. In the past few years there has been a little winter breeding on the south coast. This was never recorded before."
The migration of the Monarchs to overwintering sites in central Mexico is well-publicized, but some monarchs head for the California coast. According to the monarchwatch.org website, monarchs east of the continental divide generally migrate to central Mexico from as far away as Ontario, Canada. "Monarchs west of the divide fly to the coast of California to spend the winter. They cluster together on tree limbs during the winter months in California by the thousands, and in central Mexico by the millions." (Download the PDF on the monarchwatch.org site.)
We're glad to see the huge national campaign to plant milkweed, the host plant of the Monarchs. The Xerces Society for Invertebrate Conservation has posted a wealth of information on its website for us to take action. The Monarch population has declined by more than 90 percent in under 20 years.
“Monarch butterflies are declining due to loss of habitat,” said Monarch Watch director Chip Taylor. “To assure a future for monarchs, conservation and restoration of milkweeds needs to become a national priority.”
It also helps to provide nectar resources for the Monarchs to help them along in their migration. In our yard, they like the Mexican sunflower (Tithonia), the butterfly bush (Buddleia davidii), and blue beard (Caryopteris × clandonensis). See list of Monarchs' favorite plants on the monarchwatch.org site.
Meanwhile, an occasional Monarch flutters into our family bee/butterfly garden to sip some nectar. Sometimes territorial native bees chase them away but the Monarchs return, determined to grab some flight fuel.
A male Monarch nectaring on Mexican sunflower (Tithonia). (Photo by Kathy Keatley Garvey)
Side view of the Monarch. (Photo by Kathy Keatley Garvey)
Monarch gets ready for flight. (Photo by Kathy Keatley Garvey)
The Xerces Society for Invertebrate Conservation issued news today that is both disturbing and hopeful.
Disturbing in that the monarch butterfly population (Danaus plexippus) has declined by more than 90 percent in under 20 years.
Hopeful in that the monarch may receive federal protection through the Endangered Species Act.
The Xerces Society, the Center for Biological Diversity, the Center for Food Safety, and monarch scientist Lincoln Brower, have filed a legal petition with the U.S. Fish and Wildlife Service to protect the monarch through the Endangered Species Act. The agency must respond within 30 days as to whether the petition warrants further review.
“Monarchs are in a deadly free fall and the threats they face are now so large in scale that Endangered Species Act protection is needed sooner rather than later, while there is still time to reverse the severe decline in the heart of their range,” related Lincoln Brower, preeminent monarch researcher and conservationist, who has been studying the species since 1954.
Tragicallly, the monarchs have lost more than 165 million acres of habitat, including nearly a third of their summer breeding grounds that contain their host plant, milkweed. The female monarchs lay their eggs on milkweed and this is the only food their larvae eat.
As Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, told us today: "Might be too little too late but they have to preserve/conserve milkweeds (Asclepias spp.) That's more important than the butterfly itself."
Xerces earlier sounded the alarm on the critical role that milkweeds play in the monarch's life cycle.
Senior scientist Tierra Curry of the Center for Biological Diversity, hammered home this point in the news release: “The 90 percent drop in the monarch's population is a loss so staggering that in human-population terms it would be like losing every living person in the United States except those in Florida and Ohio.”
And the loss of habitat is equal in size to the state of Texas.
The news release said that the butterfly's dramatic decline is "being driven by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The vast majority of genetically engineered crops are made to be resistant to Monsanto's Roundup herbicide, a uniquely potent killer of milkweed, the monarch caterpillar's only food. The dramatic surge in Roundup use with Roundup Ready crops has virtually wiped out milkweed plants in midwestern corn and soybean fields."
Science policy analyst Bill Freese of the Center for Food Safety was quoted as saying: "The widespread decline of monarchs is driven by the massive spraying of herbicides on genetically engineered crops, which has virtually eliminated monarch habitat in cropland that dominates the Midwest landscape. Doing what is needed to protect monarchs will also benefit pollinators and other valuable insects, and thus safeguard our food supply.”
Monarch butterflies are known for their spectacular multigenerational migration each year from Mexico to Canada and back, the news release said.
"The population has declined from a recorded high of approximately 1 billion butterflies in the mid-1990s to only 35 million butterflies last winter, the lowest number ever recorded," according to the release. "The overall population shows a steep and statistically significant decline of 90 percent over 20 years. In addition to herbicide use with genetically engineered crops, monarchs are also threatened by global climate change, drought and heat waves, other pesticides, urban sprawl, and logging on their Mexican wintering grounds. Scientists have predicted that the monarch's entire winter range in Mexico and large parts of its summer range in the states could become unsuitable due to changing temperatures and increased risk of drought, heat waves and severe storms."
Endangered species director Sarina Jepson of the Xerces Society worries--and rightfully so--that the monarch may become extinct, just like the passenger pigeon.
We are, too. We've seen only two--two--of these majestic butterflies fluttering in our family bee garden this year.
Monarch butterfly nectaring on Mexican sunflower, Tithonia, as a territorial male longhorned bee, Melissodes agilis, takes aim. (Photo by Kathy Keatley Garvey)
Monarch butterfly heading toward a butterfly bush. (Photo by Kathy Keatley Garvey)
This is milkweed, the monarch's host plant. (Photo by Kathy Keatley Garvey)
Think of them as "the good guys" and "the good girls."
Insects such as lacewings, lady beetles and flower flies.
We're delighted to see that the Xerces Society for Invertebrate Conservation has just published a 250-page book on "Farming with Native Beneficial Insects."
The book advocates the use of beneficial insects to prey upon crop pests, thus "reducing or eliminating the use of pesticides," say co-authors Eric Lee-Mäder, Jennifer Hopwood, Mace Vaughan, Scott Hoffman Black, and Lora Morandin.
"This comprehensive guide describes how to recognize these insects and their habitat, and how to evaluate, design, and improve habitat for them," they write. They offer specific solutions, including native plant field borders, mass insectary plantings, hedgerows, cover crops, buffer strips, beetle banks, and brush piles.
The much-acclaimed book, available for purchase on the Xerces website, is drawing well deserved accolades, including this one from Claire Kremen, professor and co-director of the Berkeley Food Institute, University of California, Berkeley:
“If you are a grower or a backyard gardener, this is a ‘must have.' Readable and filled with gorgeous photos and handy charts, this book provides reams of information about how to get the upper hand on your pest issues with reduced or no pesticide use.”
Xerces officials say the release of Farming with Native Beneficial Insects coincides with its launch of a new nationwide workshop series on natural pest control: the Conservation Biological Control Short Course. The course, to begin in the West and Midwest, "provides farmers, crop consultants, and government farm agency staff with a comprehensive, hands-on training in the natural pest management strategies described in the book. A similar workshop model previously offered by Xerces trained tens of thousands of people in farm communities across the U.S. to conserve bees and restore pollinator habitat, and helped facilitate the restoration of more than 100,000 acres of wildflower habitat for bees."
Speaking of "the good guys" and "the good girls," be sure to read the UC Statewide Integrated Pest Management Project's website on beneficial insects and natural enemies. The natural enemies include assassin bugs, bigeyed bugs, brown lacewings, convergent lady beetles, damsel bugs, dustywings, syrphid flies and twicestabbed lady beetles.
What is Integrated Pest Management (IPM)? "Integrated pest management uses environmentally sound, yet effective, ways to keep pests from annoying you or damaging plants. IPM programs usually combine several pest control methods for long-term prevention and management of pest problems without harming you, your family, or the environment. Successful IPM begins with correct identification of the pest. Only then can you select the appropriate IPM methods and materials."
UC IPM points out:
- Many pests can be managed without the use of pesticides.
- Use pesticides only if nonchemical controls are ineffective and pests are reaching intolerable levels.
- Use pesticides in combination with the methods described above.
- Choose pesticides carefully. Use the least toxic, most effective material to protect human health and the environment.
- Examples of least toxic insecticides include:
- Oils; and
- Microbials such as Bacillus thuringiensis (Bt) and spinosad.
The more we learn about pests and the natural enemies of pests, the oft-heard quote, "Keep your friends close and your enemies closer" rings quite true. The more we learn about our enemies, the less likely they will be able to harm us.
A syrphid fly, aka flower fly or hover fly, nectaring on a tower of jewels. (Photo by Kathy Keatley Garvey)
A lacewing glows in the afternoon sun. Larvae eat such soft-bodied insects as mealybugs, psyllids, thrips, mites, whiteflies, aphids, small caterpillars, leafhoppers, and insect eggs, according to the UC IPM website. (Photo by Kathy Keatley Garvey)
The lady beetle, aka ladybug, is well known for its voracious appetite of aphids. (Photo by Kathy Keatley Garvey)
We all take short cuts--short cuts around the campus, to the beach, to a favorite restaurant...
Honey bees take short cuts, too.
We've often watched assorted bumble bees and carpenter bees drill a hole in a long-tubed flower to rob the nectar.
And we've watched honey bees benefitting from this behavior.
Today we observed a carpenter bee, Xylocopa tabaniformis orpifex, engaging in nectar robbing in salvia at the UC Davis Arboretum. Nectar robbing occurs when a bee or other animal circumvents the usual plant-pollinator relationship and "cheats" by entering a flower from the outside to steal nectar, thus avoiding pollination or contact with the anthers.
There's excellent information on bumble bees, their habitat needs, their behavior, and identifying characteristics in a free, downloadable PDF from the Xerces Society for Invertebrate Conservation: "Conserving Bumble Bees: Guidelines for Creating and Managing Habitat for America's Declining Pollinators."
The PDF mentions that "short-tongued bumble bees will engage in 'nectar robbing' from flowers with a long corolla tube by biting holes at the base of the corolla and drinking the nectar from the outside of the flower." The bee grabs the reward but doesn't contribute to "the plant's pollination needs."
Carpenter bee, Xylocopa tabaniformis orpifex, robbing nectar from salvia. (Photo by Kathy Keatley Garvey)
Honey bee gathering nectar from a carpenter bee's pierced hole in the long tube of a salvia. (Photo by Kathy Keatley Garvey)
Another honey bee reaping the benefits of nectar robbing by a carpenter bee. (Photo by Kathy Keatley Garvey)
It's good to see that the Xerces Society for Invertebrate Conservation and noted bumble bee expert Robbin Thorp of UC Davis have filed a petition with the U.S. Fish and Wildlife Service for Endangered Species Act protection for the beleagured rusty-patched bumble bee.
They previously filed a petition to save Franklin's bumble bee, a bumble bee known to inhabit a small area of southern Oregon and northern California. Thorp has been monitoring Franklin's bumble bee (Bombus franklini) since 1998 but hasn't seen it since August 2006 when he detected one at Mt. Ashland.
In a recent press release, the Xerces Society related that the rusty-patched bumble bee, (Bombus affinis), "has disappeared from 87 percent of its historic range (which once included 25 states). Where it is still found, this bee is much less abundant than it was in the past."
“The charismatic and once common rusty patched bumble bee has suffered severe and widespread declines throughout its range in the eastern U.S. since 1997," Thorp said. "The few scattered recent sightings thanks to intensive searches are encouraging, but the species is in critical need of federal protection.”
Why has the population of the rusty-patched bumble bee declined? Good question, and one with no fully determined answer, according to Thorp and Sarina Jepsen, the Xerces Society's endangered species program director.
"However, in related bumble bees that also are declining, researchers at the University of Illinois have recently found higher levels of a fungal pathogen and lower levels of genetic diversity," Jepson wrote in a press release. "Notably, the rusty-patched bumble bee was too scarce in the landscape to be included in these analyses."
"The leading hypothesis," Jepson says, "suggests that this fungal pathogen was introduced from Europe by the commercial bumble bee industry in the early 1990s, and then spread to wild pollinators. Although it has not been proven, the hypothesis is supported by the timing, speed and severity of the decline—a crash in laboratory populations of bumble bees occurred shortly before researchers noticed a number of species of formerly common bumble bees disappearing from the wild."
Meanwhile, we hope that Bombus affinis doesn't go the way of Bombus franklini.
As the Xerces Society's press release points out: "Pollinators are critical components of our environment and essential to our food security—providing the indispensable service of pollination to more than 85 percent of flowering plants and contributing to one in three bites of the food that we eat. Bumble bees are among the most widely recognized and well understood group of native pollinators in North America and contribute to the pollination of food crops such as squash, melon, blueberry, cranberry, clover, greenhouse tomato and greenhouse pepper, as well as numerous wildflowers."
The Xerces Society, an international organization founded in 1971 and headquartered in Portland, Ore., is a nonprofit organization that "protects wildlife through the conservation of invertebrates and their habitat" and "is at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs."
Native pollinator specialist Robbin Thorp of UC Davis is a nationally known expert on bumble bees. (Photo by Kathy Keatley Garvey)
This photo of the rusty-patched bumble bee is the 2012 work of Christy Stewart at the Pheasant Branch Conservancy in Wisconsin.