Summary of Recent Neonicotinoid Research

Alaux et al. 2010 – there is an interaction Honeybees, Nosema infections and imidacloprid that could threaten pollinators – higher susceptibility to disease.

Aliouane 2009 – Sustained exposure to neonicotinoids induced limited changes to foraging of honeybees. Acetamiprid less negative effects than other Neonicotinoids.

Bal et al. 2012 Oral 0.5-, 2- and 8-mg/kg imidacloprid causes morphological and DNA damage to sperm and testis of rats.

Bernal 2010 – Pesticides and pollen storage – J of Enc, Ento 103 pp 1963

Britain & Potts 2011 – insecticides and bees Bulletin of Insectology

Calderón-Segura 2012 - First genotoxic test of several neonicotinoids. “Low concentrations of all the tested neonicotinoid pesticides induced DNA damage”. “Although further studies investigating the details of cytotoxicity mechanisms are necessary before definitive conclusions can be drawn, our results suggest that these insecticides are risk to organisms”.

Cresswell 2010 – A review of published Neonicotinoid toxicity research - Confirmed concerns from Buglife report - environmental impacts of neonics not established. - Concludes that lab data predicts a 15% reduction in honeybee performance, BUT none of the published field studies would be able to statistically detect a change in performance at this level (i.e. one study would have been able to detect a performance reduction >33%, one >50% and the others were incapable of spotting such effects). - Conclusion - 15% could be enough in combination with other factors to cause a population decline.

Cresswell et al. 2012 Application of a medical diagnosis test to question are neonicotinoid pesticides causing honeybee population declines. “Despite the absence of decisive experimental results, our analysis shows that while the proposition is a substantially justified conjecture in the context of current knowledge, it is also substantially contraindicated by a wide variety of circumstantial epidemiological evidence.”

Diekotter 2010 Oil seed rape is good for short tongued bumblebees (despite neonics?) but conversely bad for long tongued bumblebees and the plants that they pollinate. Dittbrenner et al. 2010 – very significant impacts on earthworm growth and activity at field levels of imidacloprid

Garibaldi 2011 Global productivity of insect pollinated crops has not grown in line with other crops due to pollinator declines (I think that’s right!) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078347/pdf/pnas.201012431.pdf

Girolami et al. 2009 – Guttation - excretion of xylem fluid at leaf margins - contained amounts of neonicotinoids near those in field sprays. When bees consume such guttation drops, they encounter death within few minutes.

Girolami et al. 2012 – Effects of dust from seed drills – redesigned drills introduced by pesticide companies and regulators to reduce direct mortality of non-target insects (particularly honeybees) don’t make a significant difference to mortality rates.

Han et al. 2010 Exposure to imidacloprid-treated pollen - 48 ng g−1 (48 ppb) resulted in reduced visual learning capacities in T-tube maze evaluation and decreased olfactory learning performances measured with proboscis extension reflex. Lower foraging efficiency or orientation loss in exposed bees. Demonstrate a new means by which neonicotinoid pesticides may induce unexpected decrease in honey bee foraging efficiency, which might be linked to the honey bees worldwide decline.

Henry et al. 2012 - Non-lethal exposure of honey bees to thiamethoxam (neonicotinoid systemic pesticide) causes high mortality due to homing failure at levels that could put a colony at risk of collapse.

Kimura-Kuroda 2012 - neonicotinoids affect mammalian nervous systems and may adversely affect human health, especially the developing brain.”

Krupke et al 2012 Dead bees collected near hive entrances during the spring were found to contain clothianidin as did pollen collected by bees and stored in the hive.

Laurino et al. 2011 Toxicity of neonicotinoid insecticides to honey bees: laboratory tests Acetamiprid and Thiacloprid less toxic than Thiametoxam, Clothianidin.

Laycock et. al. 2012 Environmentally realistic imidacloprid dosages in the range of 1 μg/l reduced brood production by one third. The detrimental effects of imidacloprid on fecundity seem to arise due to nutrient limitation resulting from the failure of individuals to feed. Lu et al. 2012 – Theory presented that high fructose corn syrup contaminated with neonicotinoids fed to honeybees could cause CCD – no evidence presented that honeybees were actually exposed to such a contaminated product.

Marzaro et al. 2011 - acute poisoning of bees from ‘sowing dust’ more probably be linked to aerial contamination rather than contact with dust contaminated marginal vegetation.

Pettis et al. 2012 Pesticide exposure in honey bees results in increased levels of the gut pathogen Nosema

Scott-Dupree 2009 Of pesticides tested Neonics most toxic to adult bees, more toxic to solitary bees than bumblebees - but not a uniform pattern and recommends only way to make pesticides safe for solitary bees is to include them in tests.

Starner 2012 Imidacloprid was detected in 67 samples (89%) of Californian surface water ; concentrations exceeded safety benchmark of 19% of samples.

Stoner and Eitze 2012 Squash plants concentrations found in nectar, 10±3 ppb for imidacloprid and 11±6 ppb for thiamethoxam, concentrations in pollen, 14±8 ppb for imidacloprid and 12±9 ppb for thiamethoxam. Previous field studies measuring the concentration of neonicotinoids in canola, corn or sunflowers, where the seed was treated with the insecticide before sowing, found mean concentrations from 2 to 3.9 ppb in pollen and from 2.2 ppb to 3.0 ppb in nectar.

Tapparo et al. 2011 - Young corn (maize) plants grown in open field from coated seeds, produced guttation solutions containing high levels of neonicotinoid insecticides (up to 346 mg L1 for imidacloprid, 102 mg L1 for clothianidin and 146 mg L1 for thiamethoxam). These concentration levels may represent lethal doses for bees that use guttation drops as a source of water.

Tapparo et al. 2012 - environmental release of dust particles containing neonicotinoids can produce high exposure levels for bees, with lethal effects compatible with colony losses phenomena observed by beekeepers

Taira et al. 2011 Neonicotionid metabolites detected in the urine of patients with sub-acute nicotinic symptoms.

Tennekes 2010 – low level exposure over a long time is likely to be as damaging as high exposure over a short time

Vidau et al. 2011 - exposure to sublethal doses of fipronil and thiacloprid highly increases mortality of Honeybees previously infected by Nosema ceranae. Whitehorn et al. 2012 Bumblebee colonies exposed to field-realistic levels of the neonicotinoid imidacloprid had a significantly reduced growth rate and suffered an 85% reduction in production of new queens. (Goulson research!)

Wu et al. 2011- demonstrated sub-lethal effects on worker honey bees from a cocktail of pesticide residue on contaminated brood comb (not just Neonics). Sub-lethal effects, included delayed larval development and adult emergence or shortened adult longevity, can have indirect effects on the colony such as premature shifts in hive roles and foraging activity.