Posts Tagged: Xerces Society
If not, monarch butterflies are in a heap of trouble.
An interesting study just published in journal PLOS One by researchers at the University of Jamestown, North Dakota, and the University of Georgia, Athens, Georgia, revealed that the larvae of monarch butterflies that skip meals (host plant, milkweed) will become adults with a smaller wing size, as much as 2 percent smaller.
That's important because monarch butterflies (Danaus plexippus) are migratory animals that travel long distances, and without milkweed, Asclepias spp., their migration will be adversely affected.
In their research, “Does Skipping a Meal Matter to a Butterfly's Appearance? Effects of Larval Food Stress on Wing Morphology and Color in Monarch Butterflies,” Haley Johnson of the University of Jamestown and her colleagues also found that monarch larvae deprived of food became adults with a different wing coloration: paler wings.
This study nails home the point why we need to plant milkweed. As the Xerces Society for Invertebrate Conservation says on its website: “The loss of milkweed plants in the monarch's spring and summer breeding areas across the United States is believed to be a significant factor contributing to the reduced number of monarchs recorded in overwintering sites in California and Mexico. Agricultural intensification, development of rural lands, and the use of mowing and herbicides to control roadside vegetation have all reduced the abundance of milkweeds in the landscape.”
To address this seed shortage, the Xerces Society launched Project Milkweed to produce new sources of milkweed seed “where seed has not been reliably available: California, the Great Basin, Arizona, New Mexico, Texas, and Florida."
Bottom line, the Xerces Society is:
- raising public awareness about milkweeds' value to monarchs and native pollinators
- promoting the inclusion of milkweeds in habitat restoration efforts
- developing milkweed seed production guidelines, and
- building new markets for milkweed seed.
The Xerces website also offers sources of native milkweed seed in your state.
Meanwhile, the butterflies that overwintered in Mexico are on the move and in Texas. For more information on butterfly migration, see Monarch Butterfly, Journey North.
Monarch butterfly sightings are becoming more uncommon. (Photo by Kathy Keatley Garvey)
Monarch butterfly grabbing a sip of nectar from lantana. (Photo by Kathy Keatley Garvey)
The world's "100 Most Endangered Species" are back in the news again, and well they should be.
Back in 2012, The International Union for Conservation of Nature (IUCN) and the Zoological Society of London released a list of the 100 Most Threatened Species when the IUCN World Conservation Congress met in South Korea.
That means more attention to Franklin's bumble bee (Bombus franklinii), a critically imperiled bumble bee that UC Davis native pollinator specialist Robbin Thorp has monitored since 1998.
Thorp, emeritus professor of entomology, says the distinctively marked bumble bee has the most restricted range of any bumble bee in the world. Its habitat is--or was--a small area of southern Oregon (Douglas, Jackson and Josephine counties) and northern California (Siskiyou and Trinity counties).
Franklin’s bumble bee frequents California poppies, lupines, vetch, wild roses, blackberries, clover, sweet peas, horsemint and mountain penny royal during its flight season, from mid-May through September. It collects pollen primarily from lupines and poppies and gathers nectar mainly from mints.
Thorp and the Xerces Society for Invertebrate Conservation are the forces behind the Franklin's bumble bee campaign to find it and protect it. See the Xerces website for more information about the bee.
Thorp sighted 94 in 1998; 20 in 1999; 9 in 2000 and only 1 in 2001. Sightings increased slightly to 20 in 2002, but dropped to 3 in 2003. Thorp saw none in 2004 and 2005; one in 2006; and none since. Now scores of people from all walks of life are looking for it, but no one has found it.
Franklin's bumble bee is one of several insects on the worldwide list. The other species include several butterflies, Actinote zikani, Parides burchellanus and Pomarea whitneyi; the Seychelles Earwig (Antisolabis seychellensis); Beydaglari Bush-cricket (Psorodonotus ebneri); and a damsel fly (Risiocnemis seidenschwarzi).
Or Franklin's bumble bee.
Robbin Thorp with his computer screen showing a photo he took of Franklin's bumble bee, one of the world's 100 most endangered species. (Photo by Kathy Keatley Garvey)
This macro image of Franklin's bumble bee is the work of Robbin Thorp.
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.
It's a brief appearance but the message is important.
Pollination ecologist Neal Williams, assistant professor of entomology at UC Davis, appears briefly in a segment on native pollinators produced by America's Heartland. The show is now airing throughout the country. (Watch video)
Reporter Sarah Gardner of America’s Heartland touches on the declining population of honey bees--which European colonists brought here in 1622--and native pollinators, which are also declining.
“Farmers, scientists and others in U.S. agriculture are mounting an effort to develop a unique pollinator partnership promoting the growth of native plants on farms, orchards and ranches all across America,” Gardner said.
Williams is quoted as saying: “In the East, native bees can potentially provide all the pollination that’s necessary in the vast majority of those farms.”
It's great to see the focus on pollinators!
Gardner interviewed Mace Vaughn of the Xerces Society for Invertebrate Conservation; Ernie Shea of the Native Pollinators in Agriculture Project; and A. G. Kawamura, former California Secretary of Agriculture, among others.
Vaughn said that “unless we encourage native pollinators, consumers are going to see fewer food choices and higher prices. The conservationist is urging farmers and growers to add native plants to their growing areas in an effort to attract different bee species, butterflies, hummingbirds and other animals that can help in cross pollinating crops.”
Williams, who joined the UC Davis Department of Entomology in 2009, was a featured speaker at the International Symposium on Pollinator Conservation, held last January in Fukuoka, Japan. He explored agricultural landscape change and the role of bee life history in predicting and understanding responses of bee communities.
(Editor's Note: America's Heartland is airing the program beginning this week (Jan. 1-6) and it can also be seen on America's Heartland website. To learn when the program airs in your zip code, access this site.)
Pollination ecologist Neal Williams of UC Davis with native bees. (Photo by Kathy Keatley Garvey)