New research indicates neonicotinoids not showing up in plant pollen


According to media accounts, neonicotinoid seed treatments are taken up by plants and expressed in pollen and other reproductive parts, thus contributing to the much-publicized declines in honeybees in recent years.

But new research by Mid-South university entomologists indicates that’s not necessarily the case, as Gus Lorenz, Extension entomologist with the University of Arkansas explained in this video report from the Beltwide Cotton Conferences in New Orleans.

“When we look at the literature and the Internet, what it says is that neonicotinoids applied as seed treatments are then taken up into the plant and expressed in the pollen and in the nectar,” said Lorenz. “That’s what everyone is telling us. That’s the press that we get. Well, that’s not so much what we found.”

Pollinator issues subject of presentation at Beltwide


In their studies in corn, for example, six of the tests they conducted were positive for the neonicotinoid clothianidin with a range in the samples of 0 to 23.1 parts per billion and a mean of 2.3 ppb. The positive tests for imidacloprid, another neonicotinoid, were zero and for thiamethoxam, three positives with a range of 0 to 0.5 ppb and a mean of .1 ppb.

“So we’re not seeing that expression of the material in the corn pollen,” he noted. “When we look at cotton pollen, it’s even better. What we have is a very low percentage and very low numbers in the treatments.”

They tested soybean flowers at three locations and found no traces of neonicotinoid insecticides. The same was true of nectar in cotton. “So it’s not being expressed in the reproductive parts of the plants.”

Lorenz said the findings are important because activists groups and some beekeepers are using claims such as those he cited on the Internet to call for the withdrawal of tolerances for compounds such as Transform, which was recently registered for use in cotton.

“We can’t grow cotton in the Mid-South without Transform and similar compounds,” said Lorenz. “It is not economically feasible given the levels of insects we’re seeing.

For more about bee health issues: Honey bees - take a walk on the light side



Discuss this Video 3

on Feb 6, 2014

Mr Lorentz seems to have achieved something that no other university or government lab has done anywhere else in the world. Starting in 1994, Bayer denied that Imidacloprid was ever present in the pollen and nectar of canola, or corn. Dozens - and I mean dozens of peer-reviewed science studies - have documented the presence of imidacloprid in the pollen and nectar of every crop in which it was used as a systemic seed dressing. I refer you to the work of Dr Bonamtin's team in Montpelier Univiversity, France from the late 1990s.

'Quantification of Imidacloprid Uptake in Maize Crops'

As I said, dozens of other studies carried out in Germany, America, UK, Japan, France, Holland, Italy etc have all independently confirmed the presence of neonicotinoids in maize pollen, canola pollen, cotton pollen , soy pollen etc.

So, I look forward to seeing Gus Lorenz's peer-reviewed publication of these results, since his findings are contradicted by a vast library of other researcher's findings.

on Feb 20, 2014

To my knowledge, no reports of cotton neonic seed treatments as causing a problem for colony health has ever been made by the bee industry. In the northern states and Canada, the situation is quite different on corn and other crops. Something makes the seed treatments act differently in the south. It could something as simple as increased sunlight and heat, less no-till practices or, the that neonic laying protected underneath a snow pack and not degrading over winter significantly. My understanding is that neonics primarily have to degrade by sunlight. Whatever the reason, cotton neonic seed treatments have not been reported as problematic.

on Feb 5, 2015

2.3 parts per billion sounds like a small, insignificant, number. But, if clothianidin is 10,800 times more toxic than DDT, shouldn't this be multiplied for comparison? .23 parts per million is much larger, is this significant to bee health?
2.3 ppB by my calculations is 2.3 ug/kg. I just came accross a published journal article (Bonmatin, et el. J. Agric. Food Chem., Vol. 53, No. 13, 2005) which found that level to be a risk level for bee health.
The other scary thing is that one of the control sites had detectable levels of clothianidin?!

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