Legislating Behavior and #Beewashing

Bees have been on my mind an awful lot, lately. And that's saying something ~ considering that I'm an entomologist who has spent a lot of time studying the bees the live in our gardens and parks, as a way to better understand how to garden in ways that protect (rather than harm) these beautiful jewels of the garden.

One of my favorite bees:  Agopostemum sp. (probably, Agopostemum virescens) on a sunflower in Spokane, WA.  Photgrapher:  Gail Langellotto

So, on a normal day, I think about bees quite a bit.  But lately, everywhere I turn, bees ~ and issues related to their conservation and protection ~ have been hitting me upside the head.

First, there was the news that Jeff Reardon (D-Portland) is considering legislation to restrict home gardener use of four neonicotinoid insecticides:  dinotefuran, imidacloprid, clothianidin and thiamethoxam.  Master Gardeners keep asking me what I think about this development, and our discussions have been really interesting.

Second, I received an email announcing that the Bayer Bee Care Tour is coming to Oregon.

It can be tough to write about pesticides and bees in such a public space.  There's so much rhetoric surrounding colony collapse disorder, bees and neonicotinoids that it can be difficult to separate sound science from sound bytes.

This is made even more difficult by the reality that sound bytes are easy to digest and even easier to propagate via the internet.

• Sound byte:  neonicotinoids are killing honey bees.

By contrast, what we learn from sound science is usually much more complex and nuanced to communicate.

• Science byte:  Many insecticides can have harmful impact on honey bees.  These harmful impacts are most apparent when pesticides are mis-used, such as being applied to plants in bloom or to areas with a lot of bee activity.  In addition to insecticides, habitat loss and development, the variable nutritional quality of a bee's diet, parasites and pathogens are implicated as being major threats to honey bee health.  It seems that honey bees are so immune-compromised, that adding on one additional stressor can have dire effects on hives.  But, if we focus on the impact of pesticides on honey bees, it's important to point out that beekeeper applied pesticides (to keep Varroa mites an other honey bee pests at bay) are a major source of honey bee exposure to pesticides.  It's not just growers applying pesticides to crops (although, this is also an important part of the picture that stresses bees).  But even if we take pesticides applied to crops out of the picture, honey bees would still be exposed to pesticides.  Bee keepers are really challenged to keep healthy hives with so much pest pressure on honey bees (mites, diseases, fungi), and so few options for control.  And, I could go on and on and on . . . because the story really is so complex.

But, I want to write about these things, because a major goal of my program is to ensure that home gardeners are informed and educated about current topics ~ so that they can make the best decisions for their particular gardening situation.  Knowledge is power, right?

So what do I think about the potential ban on home gardener use of neonicotinoids?  Well, it's complex (of course!).  I see value in neonic insecticides, and I have concerns about neonic pesticides.

Here is where I see value in neonics:

1.  I like that they can be applied as a soil drench, which is a much easier pesticide application method for homeowners who need to treat a large tree or shrub, compared to a foliar insecticide spray.  I have seen too many bad examples of hose-end sprayer applications of insecticides to trees (e.g. homeowners standing underneath the drip line of the tree they were treating, or not being aware when the pesticide runs out ~ so that they continue to spray the tree with their hose ~ basically washing off the pesticide that they just applied).  Soil drenches, by comparison, are easier for most homeowners to apply in a way that does not expose them to the toxin, and in a way that may better target the intended pest ~ rather than dousing all insects that are in the canopy.
2. Neonics have been a useful tool in protecting at risk trees (ash trees in the Mid-west) and ecosystems (hemlock forests in the NE) from large scale loss because of emerald ash borer or hemlock wooly adelgids, respectively.  In these instances, the products have been a useful tool in an overall integrated pest management approach to protect trees.  The IPM approach relies heavily on monitoring and quarantine in these instances.  The pesticides are not the first tool pulled out of the toolbox ~ but they are one aspect of an overall approach to protecting these trees.  And, these trees are pollinated by wind, and not insects ~ which reduces risk to bees and other pollinators.

Here is where I have concerns about neonics:

1. My biggest concern over the last few years has been that most homeowners don't understand how persistent a neonic can be in a tree or a shrub.  I've written about this in a past blog post, and I've lectured on this extensively over the past few years ~ trying to raise awareness of this issue.  But, if you're reaching for a neonic in response to a one-time, ephermeral issue with aphids in your trees ~ you're reaching for the wrong product.  Better yet, many aphid outbreaks, if allowed to run their course, tend to disappear on their own.
2. Honestly, many plants are fairly robust to pest damage.  The plants often recover.  A plant's tolerance for damage is often less than a gardener's tolerance for damage.  But, neonics are so easy to apply as a soil drench, that I worry that folks reach for them too often ~ as a quick and long-term way to keep their trees, shrubs and other woody plants free from damage.  This isn't IPM.  IPM is a well-thought out and informed approach to pest management that makes optimal use of all IPM tools, so that pesticide applications are reduced, targeted and effective.  
3. I of course am concerned with the data that is accumulating on sub-lethal impacts of neonics on bees who gather nectar and/or pollen from flowering trees or shrubs that have been treated with a neonic.  The low doses of pesticide the bees get from the blooms is not enough to kill them, but it can be enough to change bee behavior in a way that has negative impacts on the hive.

What do I think about the proposed ban on neonics?  I have mixed emotions.

1.  If banned, I guess I wouldn't have to worry about emphasizing the potential for long-term persistence of neonics in woody plants.  It wouldn't be a matter of educating homeowners to make better decisions about the products ~ because homeowners wouldn't have a choice.
2. But ~ if banned, I'm really concerned that homeowners will instead reach for pesticide products that are broad-spectrum, foliar insecticide sprays.  These sprays have a much greater potential for harm to human health.  And, if mis-applied (such as the hose end sprayer example I gave earlier), these sprays could run off of the tree canopy and do real environmental harm ~ not to mention their broad impacts on insects that would be contacted by the spray.
3. And, because of the value demonstrated by neonics in protecting at-risk, wind-pollinated trees, I do see a role for neonics in an IPM approach to plant protection.

What about my thoughts on the Bayer Bee Tour?

Well, the original stops on the Bayer Bee Tour included 'corn belt states'.  The tour appears to have been held from Feb. 26th-April 3rd, 2013.  But now, the Bayer Bee Tour is making its way to Oregon.  How curious, that the timing of a new stop on the Bayer Bee Tour happens so soon after Jeff Reardon's proposed legislation.

I'm not against Bayer ~ or any agrochemical company.  Bayer helps to develop new pesticide products that can be important tools in an IPM approach to plant protection.  And ~ before you jump on me for that last sentence, consider that one of the reasons that bee keepers are so challenged by Varroa mite is that there hasn't been an investment in developing new products for managing mites in bee hives.  Growers need tools to manage plant pests in the context of a well-planned IPM program ~ and without access to high quality tools, there is the potential for increased use and reliance of inferior tools.

I'm instead annoyed that the Bayer Bee Care Tour has rented facilities at major universities (Ohio State, Univ. of Illinois, Iowa State, University of Nebraska, University of Minnesota . . . and now, Oregon State University), and marketed it in a way that suggests that OSU is a collaborator on the tour.  Although completely within their right (these facilities are available for any group to rent and use), I worry that their Bee Tour announcement promotes the false impression that these stops have been planned with and endorsed by the Universities.  When in actuality, the entomologists I've talked to at Oregon State were largely caught by surprise by this upcoming Bayer Bee Tour stop, and were only called after the fact by Bayer to see if they would participate in a panel discussion (most, if not all, have said 'no').

It seems that the more open and inclusive approach, if the goal is to align Bayer's bee protection efforts with what is going on at Land Grant Universities, would be to invite Oregon State researchers to the table from the beginning ~ rather than trying to tack folks on as an afterthought.

Does Wearing Perfume Confuse Bees?

This weekend, the following snippet in the Oregonian's Home and Garden section caught my eye.

Another reason to avoid artificial fragrance: It can confuse bees. Bees are vital to the natural world  thanks to the important work they do to pollinate flowers. They are attracted to the sweet-smelling scent from actual flowers, and are also attracted to artificial scents found in body washes, perfumes, shampoo, air fresheners and scented candles. This confusion by bees can lead to fewer pollinated flowers. One way to help is to choose fragrance-free options whenever possible.

-- Danny Seo, eco expert, Universal Press Syndicate

Is this really true? Will my locally-sourced and produced lavender soap draw bees away from the real deal?

As someone who uses lavender-scented soap and a kukui-nut scented lotion, could I be responsible for the current pollinator crisis?

Not likely. Bees find flowers by scent, but they also orient by sight. And, bees are remarkably good at 'remembering' which floral visits were profitable and which were a waste of time.  In tests of honey bees, they performed remarkably well at discriminating among similar scents, to hone in on the scent that was previously associated with a 20% sucrose reward.  Of the 1848 odor pairs, the bees were able to choose the 'reward' scent' 97.0%  of the time (1793 odor pairs). Only seven odor pairs (i.e. 0.4% of all odor pairs) were not distinguished by experimental bees trained to a given scent.  The other 2.6% of scent 'failures' (48 odor pairs) could be attributed to a single poor-performing bee.

Other studies of solitary bees have found that you can get a response from their antennae to certain scents, but that this doesn't mean that they'll visit the source of the scent.  Visual stimuli (how a flower looks) and previous floral rewards (if a flower gives nectar and/or pollen) matter.

So . . . even if we use scented shampoos, lotions, etc., we don't really look like flowers, and we probably don't provide a nectar reward.  Bees are unlikely to be fooled.

My favorite test of this topic was presented at the 2009 annual meeting of the Entomological Society of America, by my friends John Carlson  and Mark Fox.  The abstract of their presentation, entitled 'Is that a person or a flower?  Experimental evaluation of the standard recommendations given by physicians to venom-allergic patients regarding foraging Hymenoptera'.

Could this shirt put you at risk? Photo Credit:  Dayna Inc., the UnHawaiian Shirt Company.

Physicians give patients with life-threatening allergies to Hymenoptera venom, advice regarding avoidance of defensive stings as well as avoidance of foraging workers. Some of this advice is in contrast to recommendations given by USDA and other organizations that employ entomologists: avoid wearing bright colors, floral patterns,and perfume that might attract foraging insects. The likelihood of a bee or wasp to alight upon clothing was tested in haphazardly chosen locations around New Orleans, LA over the summer of 2009. Dark clothing and bright, floral patterned clothing were placed on the ground and observed for 10 minutes. Perfume was applied to all clothing for a second 10 minute observation period. Control plots were observed during each replicate to ensure that foraging Hymenoptera were active on flowers at the location. No species from which allergy has  been reported alighted on any article of clothing for the duration of the study. These results were expected based on the known sensory cues used by social Hymenoptera in locating food. In light of these findings, venom-allergic patients should not be advised to avoid perfume or bright clothing, especially because dark clothing has been associated with stings from workers defending honey bee colonies.

Mark and John used perfumes with the highest concentration of natural floral scents.  They purchased the gaudiest floral shirts they could find ~ as well as shirts with 'realistic' looking flowers.  Alas, the shirts did not receive any bee or wasp visitors.

Another Benefit of Pollinators in the Garden?

In an article published in the journal Current Biology, researchers from the University of Wurzburg in Germany report that the presence of honey bees deters damage by plant feeding caterpillars. Tautz and Rostas measured plant damage to soybeans and peppers (with and without fruit) by beet armyworms, in the presence and absence of honey bees. When the plants were not fruiting, the presence of honey bees reduced caterpillar damage by 61-69%, compared to plants with the beet armyworms but without the honey bees.

The scientists suggest that damage is reduced, because the caterpillars sense vibrations by the bees' wings. In an earlier study, Tautz and Markl found that caterpillars use hairs on their body to sense the vibrations of hunting wasps. When wasps are perceived, the caterpillars stop moving, stop feeding, and vomit. This reaction delivers a degree of protection to the caterpillars - those exhibiting these behaviors are attacked 30% less than caterpillars that continue to feed.

The recent Tautz and Rostas study is exciting, because it suggests another potential benefit of pollinators in the garden. In addition, this study provides a new perspective on interactions between plants, herbivores and pollinators. Scientists have long known that herbivore damage can reduce the attractiveness of flowering plants to pollinators. But, this is the first study that I know of that suggests that pollinators can have a similar effect on herbivores.