Science Magazine

Scientists Discover Another Cause of Bee Deaths

Posted on the 18 August 2013 by Ningauble @AliAksoz

Scientists have been trying to discover why the bees were dying, for years. Is it cell phone towers? Pesticides? bacteria? Now we have a new research that pinpoints some of the probable causes and the results  which are more complex, pervasive and ultimately much more scary.

The researchers behind the study in PLOS ONE - Jeffery S. Pettis, Elinor M. Lichtenberg, Michael Andree, Jennie Stitzinger, Robyn Rose, Dennis van Engelsdorp – collected pollen from hives on the east coast pollinating cranberry, watermelon and other crops and fed it to healthy bees. The pollen they were fed had an average of nine different pesticides and fungicides and one sample contained a deadly mixture of 21 different chemicals.  those bees showed a significant decline in their ability to resist infection by a parasite called Nosema ceranae which has been implicated in Colony Collapse Disorder or CCD and the bees that ate pollen with fungicides were three times more likely to be infected by the parasite.

Fungicides, thought harmless to bees, is actually a significant part of Colony Collapse Disorder.

bee_face.jpg.662x0_q100_crop-scale

Scientists had struggled to find the trigger for so-called Colony Collapse Disorder (CCD) that has wiped out an estimated 10 million beehives, worth $2 billion, over the past six years. Suspects have included pesticides, disease-bearing parasites and poor nutrition. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists at the University of Maryland and the US Department of Agriculture have identified a witch’s brew of pesticides and fungicides contaminating pollen that bees collect to feed their hives. The findings break new ground on why large numbers of bees are dying though they do not identify the specific cause of CCD, where an entire beehive dies at once.

 

Before the link to bee deaths was neonicotinoids but this study shows that the problem is a combination of many chemicals, which makes the problem far more complex.

 

The authors write, “[M]ore attention must be paid to how honey bees are exposed to pesticides outside of the field in which they are placed. We detected 35 different pesticides in the sampled pollen, and found high fungicide loads. The insecticides esfenvalerate and phosmet were at a concentration higher than their median lethal dose in at least one pollen sample. While fungicides are typically seen as fairly safe for honey bees, we found an increased probability of Nosema infection in bees that consumed pollen with a higher fungicide load. Our results highlight a need for research on sub-lethal effects of fungicides and other chemicals that bees placed in an agricultural setting are exposed to.”

“Bee populations are so low in the US that it now takes 60% of the country’s surviving colonies just to pollinate one California crop, almonds. And that’s not just a west coast problem—California supplies 80% of the world’s almonds, a market worth $4 billion.” Quartz notes.

So we know that the chemicals used on crops, kill – humans? – bees. We need a new system of rules and laws that dictate what can be sprayed where, how, and when to minimize the negative effects on bees and all living beings while assisting in crop production.

 

N.


Back to Featured Articles on Logo Paperblog