The Pollinator's Dilemma

Pam Smith
By  Pam Smith , Crops Technology Editor
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Varroa mite, a small tick like insect, is draining the life from the honeybee industry. (Photo by USDA-ARS/Steve Ausmus)

DECATUR, Ill. (DTN) -- It's Pollinator Week and my bees are oblivious to the hoopla. They are too busy gorging on the long strip of blooming white clover my neighbor left uncut this week to care about headlines.

Earlier this spring, my husband and I had one of those sticky conversations with our neighbor about his use of pesticides. We simply asked that he spray early or later in the day when our bees were less likely to be foraging. His garden has flourished since we installed the hives and there is always the side bribe of a gift of honey at harvest to urge compliance. Leaving the clover strip was a sweet and surprising concession on his part.

It's naive to think similarly successful one-on-one conversations will resolve the many dilemmas facing pollinators. While small steps help, federal mandates are already in place to force compliance. President Barack Obama's May announcement (http://1.usa.gov/…) of a federal strategy to promote pollinator health has agencies and state governments scrambling to put together all sorts of plans.

For example, Clemson University's Department of Plant Industry and their Extension Service have teamed up with a software developer to come up with a program to map the estimated 25,000 to 30,000 hives in South Carolina. The idea is to limit exposure to honey bees through education and communication between beekeepers and pesticide applicators. Other voluntary programs are cropping up that include planting seeds to increase habitat. Bee research programs are getting funded to explore better bee genetics that might resist the insects and diseases that cause many of the staggering colony losses.

I love it that bees are popular again, but the pollinator dilemma is frankly one of the most complex issues I've run across in my decades of following agricultural issues. I'm thrilled that more dollars are going to pollinator research, but again, many of the results and actions I've seen so far have more to do with emotion than real science.

This week the provincial government of Ontario announced on July 1 it intends to be the first jurisdiction in North America to limit planting of corn and soybeans treated with neonicotinoids. It will be a phase-out deal -- by 2017 all farmers wanting to use neonic-treated seeds will have to prove they have a pest problem that warrants use of the product.

In the U.S., the EPA has already indicated it will not approve new applications for neonics until pollinator risk assesments are complete. EPA is conducting a new risk assessment for neonics that could lead to new regulatory decisions on products already in use.

Moves like this have Mississippi State University entomologist Angus Catchot on the alert. I exchanged messages with Catchot after he issued a news release this week discussing the complexities between bees and the environment and the use of neonicotinoid (neonic) insecticides in the Midsouth.

One of the many complaints about the use of neonics is that they are systemic, which means they move through the plant as it grows from seed into seedling. Catchot said seed treatments provide about 21 to 28 days of protection after planting.

"Midsouth entomologists have conducted a lot of research on whether or not neonics are present in the nectar or pollen of our major row crops," Catchot said in the release. "Soybean is the crop bees prefer to forage on based on our surveys, and in soybean, we found zero occurrence of neonics in the flowers of the plant when the soybeans were planted with a neonic seed treatment."

In cotton, they found no occurrence of neonics in the nectar and very low occurrence in the pollen.

"In corn, we did find low levels about 20% of the time, and they ranged from about three to six parts per billion, but they were more prevalent with chemical rates greater than what is typically used in the Midsouth," he said. "Based on our research, it does not appear very likely in our region of the country that bees are picking up neonics at any appreciable level from nectar or pollen in the major row crops we grow."

Further research by Catchot's group indicates 99% of the total amount of pesticide applied as a seed treatment in these three crops is gone before the plant produces flowers. He said they have not looked at neonic levels in surface water.

These are the kind of studies we need to determine what is really happening in the field. We also need honest assessments of the unintended tradeoffs to bees and other pollinators if we go back to less selective foliar insecticides to manage early-season pests.

However, I tend to agree with Mississippi's bee expert Jeff Harris' assessment of the number one cause of bee decline: "My top three reasons for bee colony death are Varroa mites, Varroa mites and Varroa mites," said Harris. "This is my sarcastic response to the heavy emphasis in the press on the effects of insecticides and other pesticides on honey bees."

Varroa mites are a tick-like parasite that lays eggs in the brood cells within the hive and emerge when the bee hatches. They are nasty, awful creatures that transmit a wide range of diseases.

There's no question pesticides can cause bee losses, but pinning the plight of pollinators on pesticides alone is an oversimplification of a much bigger problem. I'm for world-wide elimination of the Varroa mite. Surely they do not yet have a support group!

For a fascinating inside look at how bees develop and varroa mite preys upon the bee go to:

https://www.youtube.com/…

Pamela Smith can be reached at Pamela.smith@dtn.com

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Pam Smith