The honey bee guru continues to answer a range of questions. The latest concerns the effect of marijuana growing sites on honey bees.
We thought we'd share his answer, which deals with honey bees, pollinators, Cannabis, pesticides, and what could happen to beekeepers who stumble upon a pot farm.
The question: "What is the effect, good or bad, that marijuana plants and marijuana grow sites have on the honey bee? From what I understand, these grow sites are using chemicals to control pests year round. In some cases, I hear that marijuana growers are importing chemicals from Mexico that are stronger and work better to control pest."
Mussen answered the question succinctly and openly.
"As you might guess, since marijuana is still considered an illegal plant to grow by the federal government," he replied, "it is no surprise that there are no pesticides registered for use on the 'crop.' Some states are trying hard to build a list of acceptable products, but here is the problem. So far we have registered products based on contact and oral toxicities to mammals. We have only run inhalation toxicities on a few very potent and stinky products (fumigants). You can get up to 10X the dose of a chemical, from the same amount of plant mass, if you smoke it versus eating it.
"There are quite a number of websites dedicated to pot growing. When pest control becomes the topic, most sites suggest mechanical methods or use of products allowed in organic agriculture. However, those organic pesticides have not been checked for inhalation effects, either."
"Thus, practically any pesticide that is used will be illegal. Given that, growers are apt to determine which materials work best on the pest at hand on other crops, acquire those materials, and use them. The regulators know this, and in states where marijuana currently is legal, the states are testing some of the products on the shelves to see what pesticides are in them. The samples have been found to be pretty clean, for the most part."
Mussen acknowledged that blooming hemp plants are attractive to many pollinators. "I have no idea what the pollen and nectar might do to them when the bees consume it. We can provide a pretty good idea of what will happen when pesticide products used on other crops are applied to the bloom (at agricultural rates), but since nothing is registered, there is no way of guessing what might be used. For the standard fee of just under $400, we can send a sample of the bees or pollen to the USDA AMS pesticide residue detection lab in Gastonia, N.C., and they can tell us the residues. Butthat doesn't help us much in terms of regulatory assistance.
"Pot growers probably won't care if they repel or kill visiting bees," Mussen speculated. "Pollinated blossoms become senescent too quickly, and do not produce the maximum amount of important resins if they are pollinated early in their cycle."
"Up to this time, I have not heard of beekeepers reporting damage from pesticides applied to marijuana, but it is likely to happen before long. Beekeepers are more worried about being shot if they accidentally get too close to a pot farm."
The article: "Neonicotinoid Ppesticide Exposure Impairs Crop Pollination Services Provided by Bumblebees."
Seeking his expertise, journalists are contacting Thorp, distinguished emeritus professor of entomology at the University of California, Davis, who maintains an office at the Harry H. Laidlaw Jr. Honey Bee Research Facility, and also works at the Bohart Museum of Entomology.
The research, by a team of six UK colleagues, indicates that neonics are hindering the pollination services of bumble bees. Corresponding author is Nigel E. Raine of the School of Biological Science, Royal Holloway University of London and his team wrote in the abstract:
"Recent concern over global pollinator declines has led to considerable research on the effects of pesticides on bees. Although pesticides are typically not encountered at lethal levels in the field, there is growing evidence indicating that exposure to field-realistic levels can have sublethal effects on bees, affecting their foraging behaviour, homing ability and reproductive success Bees are essential for the pollination of a wide variety of crops and the majority of wild flowering plants but until now research on pesticide effects has been limited to direct effects on bees themselves and not on the pollination services they provide. Here we show the first evidence to our knowledge that pesticide exposure can reduce the pollination services bumblebees deliver to apples, a crop of global economic importance. Bumblebee colonies exposed to a neonicotinoid pesticide provided lower visitation rates to apple trees and collected pollen less often. Most importantly, these pesticide-exposed colonies produced apples containing fewer seeds, demonstrating a reduced delivery of pollination services. Our results also indicate that reduced pollination service delivery is not due to pesticide-induced changes in individual bee behaviour, but most likely due to effects at the colony level. These findings show that pesticide exposure can impair the ability of bees to provide pollination services, with important implications for both the sustained delivery of stable crop yields and the functioning of natural ecosystems."
The researchers studied Thiamethoxam, one of the neonics.
Thorp, who was not involved in the research, is a global expert on bumble bees, as well as other bees. He co-authored Bumble Bees of North America: an Identification Guide (Princeton University) published in 2014, and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), also published in 2014.
Thorp was quoted today in the well-researched Washington Post piece, "New Research Reignites Concerns that Pesticides Are Harming Bees," written by freelance journalist Chelsea Harvey, who specializes in environmental health and policy.
“Most of the studies in the past have focused on direct effects on the bees, both the adults and the larvae,” Thorp told Harvey. "These can include effects on bee mortality or reproduction...“This study now clearly demonstrates that in addition to effects on the bees, both direct effects and sublethal indirect effects, that these effects are influencing their ability to pollinate plants. And they used apple as an example of this, as an important crop.”
The topic is quite controversial, but the importance of pollination is not. Inadequate pollination can lead to unfavorable effects on agricultural crop production. For example, bumble bees may not forage on the apple blossoms as much or as long. That could lead to poor fruit quality and decreased apple production.
Why are bumble bees important? “They're extremely important in pollination of our native ecosystems, and many of them…are important contributors to crop pollination," Thorp told the Washington Post.
Bumble bees are known for their specialized pollination of tomatoes and watermelon, but they also pollinate many other agricultural crops.
Thorp points out that with the decline of the honey bee population, the work of other pollinators is becoming increasingly crucial.
Thorp anticipates that the study will open doors for more research involving neonics and wild bees. "Even if the study can't be generalized to all bees or all crops, it raises more questions in the ongoing debate over pesticide use in the U.S.," Harvey pointed out in her news article.
“I think it's kind of a wake-up call to growers that they ought to be paying more attention to what they're putting on their crops,” Thorp told Harvey. “Because it's coming right out of their pocket as well if they're damaging the ability of pollinators that they rely on to pollinate their crops.”
Thorp has long been part of the mission to save the declining bumble bee population. He works closely on bumble bee conservation with Xerces Society for Invertebrate Conservation, headquartered in Portland, Ore.
The Xerces Society emphasizes the importance of bumble bees on it website. ""Bumble bees are important pollinators of wild flowering plants and crops. They are generalist foragers, and thus do not depend on any one flower type. However, some plants rely on bumble bees to achieve pollination. Loss of bumble bees can have far ranging ecological impacts due to their role as pollinators. In Britain and the Netherlands, where multiple pollinator species have gone extinct, there is evidence of a decline in the abundance of insect pollinated plants."
"Bumble bees are able to fly in cooler temperatures and lower light levels than many other bees, which makes them excellent crop pollinators," according to Xerces. "They also perform a behavior called 'buzz pollination,' in which the bee grabs the pollen producing structure of the flower in her jaws and vibrates her wing muscles. This causes vibrations that dislodge pollen from the flower. Some plants, including tomatoes, peppers, and cranberries, benefit from buzz pollination."
Will all the pollinators please stand up!
Or do a fly-by like the Blue Angels or a crawl-by like babies competing in a diaper derby.
Bees--there are more than 4000 of them in North America--are the main pollinators, but don't overlook butterflies, beetles, birds, bats and moths.
Here's proof positive that flies can pollinate. If you look closely at this little bee fly on a Mexican sunflower (Tithonia), you'll see that it has just grabbed some pollen. It's a member of the genus, Villa, and family, Bombyliidae, according to fly expert Martin Hauser of the California Department of Food and Agriculture.
Many folks mistake flies for bees. Look through any stock photo catalog or macro insect images on Flickr or a Facebook page and you'll often see hover flies, bee flies and other flies identified as bees.
Three of the easiest ways to differentiate a fly from a bee:
- A fly has one set of wings. A bee has two sets.
- A fly has short, stubby antennae. A honey bee doesn't.
- A fly has no corbicula or pollen basket. A honey bee (worker bee) does.
Welcome to the Pollination Nation!
For more information on bee flies, see BugGuide.net. For syrphids, aka flower flies or hover flies, read the UC Statewide Integrated Pest Management's information on managing pests or read entomologist Robert Bugg's free downloadable PDF on the UC ANR website, Flower Flies (Syrphidae) and Other Biological Control Agents for Aphids (Publication No. 8285).
But when it comes to UC Davis Picnic Day 101, the "101" doesn't mean inexperience. This is the 101st annual celebration, which means UC Davis has been doing this for a century.
It's an event billed as entertaining, educational and informative--and it is. Plus, it's just plain fun!
Longtime friends and family get to hug ya. Entomologists get to bug ya. Visitors will see plenty of insects and other arthropods from 10 a.m. to 3 p.m. at two sites: Briggs Hall on Kleiber Hall Drive and the Bohart Museum of Entomology on Crocker Lane.
Theme of the campuswide picnic is “The Heart of Our Community,” but over at the Bohart Museum, the theme is “The Good, the Bad and the Bugly.” The museum, directed by Lynn Kimsey, professor of entomology at UC Davis, will feature pollinators. The museum houses nearly 8 million specimens. It also houses a live “petting zoo,” comprised of Madagascar hissing cockroaches, walking sticks and a rose-haired tarantula named Peaches, a crowd favorite.
At Briggs Hall, a new event is the Pollinator Pavilion, where visitors can see and learn about bees, butterflies and other pollinators. Pollination ecologist/graduate student Margaret “Rei” Scampavia is coordinating the project. “We're going to have painted lady butterflies, monarchs, male blue orchard bees, and a live bumblebee colony,” she said. Other events at the Pollinator Pavilion will include puppet shows, a chance to practice pollinator observations, museum specimens, and information on how individuals can help support healthy pollinator populations.
Forensic entomologist Robert Kimsey will portray “Dr. Death,” showing methods used in forensic entomology in 122 Briggs. The Phil Ward lab will assemble a display on the incredible diversity of ants. The Sharon Lawler lab will display aquatic insects and answer any questions about them.
Visitors can sample six different varietals of honey at a honey tasting table in the Briggs courtyard. The flavors are coffee blossom, meadowfoam blossom, buckwheat, creamed clover, cotton and chestnut, said Elina Niño, Extension apiculturist. A bee observation hive will be set up in across from the courtyard, where Niño and staff research associate Billy Synk will answer questions about bees.
Also at Briggs: graduate student Stacy Hishinuma and forest entomologist Steve Seybold, a chemical ecologist with the USDA Forest Service, Pacific Southwest Research Station, Davis, and an affiliate of the UC Davis Department of Entomology and Nematology, will display forest insects. Medical entomology graduate students will set up displays about diseases vectored by mosquitoes and other insects. The Sacramento-Yolo Mosquito and Vector Control District will provide an educational exhibit about mosquito abatement. Exhibits also will include such topics as fly fishing/fly-tying.
The UC Statewide Integrated Pest Management Program (UC IPM) will be giving away lady beetles, aka ladybugs, in front of Briggs Hall. They will answer questions about insects and display many of their books.
The Graduate Student Entomology Association (GMSA) and the Entomology Club will be out in force, coordinating and staffing the many insect activities. If you like bugs, you can buy an entomology t-shirt or have a bug painted on your face. The Bohart Museum also will be selling t-shirts and other items in its gift shop, which is open year-around.
If you're going to the parade, which starts at 9:30 a.m., be sure to check out the Entomology Club's float. It will not be an "itsy bitsy spider." It will be one ritsy gigantic spider! Following the parade, the float will be showcased in front of Briggs Hall.
What a day it promises to be...the good, the bad, and the bugly...
With your camera!
If you're into pollinators, plants and photography, and want to share your work nationally, here's a new project for you.
Bay Area native bee enthusiast Celeste Ets-Hokin, who launched the Wild Bee Gardens app (with identification assistance from consultants, including native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis), alerted us to the contest.
It is "designed to raise awareness about the dazzling diversity of North America's native bees and other pollinators," she said, "and to engage residents from coast to coast in the vital and rewarding business of creating a continental tapestry of wild bee gardens,"
CFS, headquartered in Washington, D.C., with branch offices in San Francisco, Honolulu and Portland (Ore.) describes itself as "a national non-profit public interest and environmental advocacy organization working to protect human health and the environment by curbing the use of harmful food production technologies and by promoting organic and other forms of sustainable agriculture. CFS also educates consumers concerning the definition of organic food and products."
Judges will choose numerous winners, and each will receive a free Wild Bee Gardens app to keep, or give as a gift, "so that you can share your enthusiasm for wild bees and their gardens with your friends and families," Ets-Hokin said. Winners also will receive a pollinator swag bag from CFS.
Want to learn more about the submission guidelines and selection criteria? Access http://centerforfoodsafety-wildbees.tumblr.com . The deadline to submit photos is April 17.
If you can't identify the pollinator, not to worry. After the judges select the winners, Thorp will identify the bees. He's a co-author of California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), along with colleagues Gordon Frankie, Rollin Coville and Barbara Ertter. Thorp also co-authored Bumble Bees of North America: an Identification Guide (Princeton University Press).
Speaking of bumble bees, they seem to be quite scarce this year. We saw our first black-tailed bumble bee (Bombus melanopygus) of the season on March 15 on Spanish lavender in Vacaville.