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Monthly Archives: August 2012

Neo-Nics and your planet

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Once, in the Land of MoreWar, a type of biocide (imidac|oprid) derived from nicotine (thus called a ‘neo-nicotinoid’) was sold by a corporation. This corporation made large profits, so this corporation and other corporations quickly created additional neonicotinoid biocides–maybe better; maybe worse; but advertised just the same. Many customers were ignorant of well-known biocide side-effects, like toxicity to bees who harvest nectar and pollen from some treated plants. (These types of neonicotinoids are retained and systemically-dispersed throughout the plant, including the pollen.) If the biocide in the pollen was insufficient to kill the bee, it might damage the bee in other ways, such as weakening bee immune systems and/or destroying the bees’ ability to return to the hive after foraging. A sub-lethal dose can kill bees in ways resembling a human drunk driver’s auto accident.

All man-made biocides will break down into simpler chemicals eventually. Some of these breakdown products can be even more deadly than the original biocide. Yet more unintended consequences.

This is a really good but long article on these biocides.

Here’s the science:

“The long persistence, after one and two years, of imidac|oprid in soils has been demonstrated in this study. Retention of imidac|oprid in soils, coupled with the ability of sunflowers to recover the insecticide during the next cultivation, clearly explains the presence of imidac|oprid in untreated plants. This situation is also observed for maize and several weeds or adventitious plants (plants which grow in fields but which have not been sown). For untreated wheat, rape and barley, imidac|oprid is also recovered to a lesser extent from contaminated soils (Bonmatin et al. 2000b).

Seed treatment using imidac|oprid protects plants against insects and is supposed to vanish before the arrival of pollinator insects. However, a new phenomenon has been demonstrated. We have shown that the relative amount of imidac|oprid reaches a minimum, then increases in sunflowers from the time of the capitulum formation. As a consequence, relatively high levels are observed during flowering in the flowering heads. At this time, the capitulums of sunflowers contain a mean value of 8 μgkg–1 of imidac|oprid. Another study on maize indicates a similar situation. The ascent of imidac|oprid during flowering appears to be general behaviour, due to both enhanced metabolism and the strong mobilisation of resources for plants producing large amounts of grains such as sunflowers and maize.

Our data reveals the presence of imidac|oprid in pollens with average values of 3 μgkg–1 (sunflowers and maize). Thus, imidac|oprid appears to be bioavailable for bees in fields, in a range of concentrations corresponding to that of sub-lethal effects on bees and especially concerning the foraging activity (Colin and Bonmatin 2000; Colin 2001). This risk situation with respect to sunflowers and maize is worsened when considering (i) the additional toxic action of several imidac|oprid metabolites (Nauen et al. 1998; Oliveira et al. 2000) as well as (ii) the very low concentrations inducing chronic mortality of bees which are in the 0.1–1 μgkg–1 range (Suchail et al. 2001; Belzunces 2001).”

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Posted by on Mon, 2012 in General Knowledge