TWO NEW SCIENTIFIC ARTICLES: a new suspicion of neonicotinoid pesticides…

Tuesday 03 April 2012

Thiamethoxam Sub-lethal effects pesticides neonicotinoids Imidacloprid honeybee bumblebees

Two new scientific studies, developed in France and in the UK, show a proof of the deleterious action of pesticides of the family of neonicotinoid on honeybee and bumblebee colonies. At very low doses, Thiamethoxam and Imidacloprid revealed to significantly disturb the activity of honeybee and bumblebee colonies. This raises once more the implication of neonicotinoids in the weakening and collapse of pollinators, and particularly in honeybee populations.

Bourdon sur fleur (bourdon.gif)

Abeille puce RFID (abeille-puce-rfid.jpg)

Since their publication on March 29th 2012 in Sciencexpress, two articles strongly raised attention in the beekeeping sector and even beyond. The two studies studied the effects of sublethal doses (low doses not directly fatal) of insecticides of the family of neonicotinoids on colonies of bees, Apis mellifera, and bumblebees, "Bombus terrestris".

Mickaël Henry and his colleagues (Henry et al., 2012) have shown that the loss of honeybee foragers caused by exposure to low doses of Thiamethoxam reached a level that could be hardly compensated by the colony. Therefore, such an effect on foragers can highly alter the activity of the colony itself and its survival, finally contributing to its decline.

In parallel, Penelope R. Whitehorn and her colleagues (Whitehorn et al., 2012) have shown that low doses of Imidacloprid significantly affected the colonies of bumblebees by reducing their development and their reproduction.

These two studies call into question the sublethal effects of neonicotinoid insecticides on pollinators, and their implication in the weakening and losses of bees. These effects have already been shown on honeybees, with often similar methodologies, and the problem of the sublethal effects have already been addressed on several occasions reprises (Aliouane et al., 2008; Blacquière et al., 2012; Bortolotti et al., 2003; Colin et al., 2004; Decourtye et al., 2003, 2004a, 2004b, 2005, 2011; Desneux et al., 2007; Schneider et al., 2012; Yang et al., 2008). Once more today, the subject is brought to the fore.

These two articles are thus adding to previous scientific studies and

- reinforce the weight of the evidence that pesticides applied at low doses may affect the health of bees and of the colony;

- show the aberration of the absence of evaluation of sublethal effects of pesticides on bees in pesticide risk assessment schemes.

Indeed, if the publication of such studies allow Member States to implement prohibitions on these substances proven hazardous to bees, the basis of the problem lies elsewhere: in the process of authorization of pesticides that completely ignores the importance of sublethal effects on bees and let be put on the market substances with harmful effects for pollinators.