Now that the dust has settled a bit, I wish to make it clear that I am  
not an apologist for Bayer or Big Ag. My point of view in all of this  
has been that keeping bees in agricultural areas is fraught with  
peril, that beekeepers need to be responsible. You can't expect  
growers to change their procedures based on suspicions and hunches. A  
solid case has to be made, and the abuse of pesticides BY beekeepers  
has to be thoroughly considered, before going after the other guy.

There is plenty of evidence that pesticides, including neonics, harm  
bees. Beekeepers have been hit hard by insecticides since forever.  
This is nothing new. What is new is the difficulty in showing a direct  
cause and relationship in field conditions. I mentioned a while back  
that I thought it was foolish to keep bees around apple orchards after  
the bloom period. I wouldn't want them there during the bloom either,  
but there is a demand for it for which beekeepers are handsomely paid.

If you use your bees to pollinate, you must be on the alert for toxic  
effects. One of the problems, however, is that these various studies  
are pretty difficult reading for average person. You have to go  
straight to the conclusions and then work back through their methods  
to get a sense of what it "means" and whether they actually did what  
they said they did, and proved anything at all. The following work  
shows that bees do bring neonics in with apple pollen at very low  
level, too low to kill them outright.

However, the quantities could produce harmful effects on the bees and  
especially the developing larvae. Again, they point out that similar  
problems occur with in-hive chemicals. Apoptosis or programmed cell  
death is mentioned here. This is a mechanism where living creatures  
rid themselves of damaged cells and dna. When the damage is  
sufficient, individual cells "commit suicide" and are processed as  
waste by the immune system. Low levels of pesticides are known to  
trigger apoptosis.

 > Pesticides applied in the field are detectable in both pollen loads  
and in bee bread from inside hives. Both forms of pollen represent the  
protein sources for adult and the developmental stages of bees, large  
amounts being consumed by nurse bees, and to a lesser extent by  
larvae. It is evident, therefore that honey bees can be exposed to  
lethal or sublethal doses of pesticides in their food, which can  
consequently have an impact on their development or longevity. The  
oral LD50 for adult honey bees of diazinon is 0.09 µg, LD50 of  
thiacloprid is 17.32 µg.

 > The toxicological properties of insecticides and fungicides are  
indicative of adverse effects on adult bees and also sublethal effects  
at the tissue level causing morphological, histochemical and  
cytochemical changes. For example, imidacloprid or coumaphos treatment  
induced reduction the size of hypopharyngeal gland acinus and heat  
shock protein localisation in cell nuclei and cytoplasm.

 > Coumaphos triggered an increased level of programmed cell death and  
imidacloprid extended necrosis. In honey bee larvae exposed to  
Amitraz, both necrotic and apoptotic cell death have been demonstrated  
indicative of subclinical effects and increased mortality as indicated  
in toxicological experiments conducted on bee brood and adult bees.

"Residues of Pesticides in Honeybee (Apis mellifera carnica) Bee Bread  
and in Pollen Loads from Treated Apple Orchards"  by  Maja Ivana  
Smodis Skerl, et al
Agricultural Institute of Slovenia, Ljubljana

Reviewed by
Peter Loring Borst
Ithaca, NY  USA
+42.347999, -76.495239 
    
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