Bienen haben ausgeprägte Sinnesorgane zur Wahrnehmung von Blütendüften. Stickoxide aus Autoabgasen beeinträchtigen diese allerdings so stark, dass Blüten nicht mehr als Nektar- und Pollenquellen erkannt werden. Eine auf Nature veröffentlichte Studie von Wissenschaftlern der Universität Southampton belegt exemplarisch, dass die Fähigkeit der Bienen, Rapsblüten zu erkennen rapide abnimmt, sobald Dieselabgase im Blütenduft enthalten sind:
A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by removing the two chemicals rendered undetectable, significantly reduced the ability of the trained honeybees to recognize the altered odour. Furthermore, we found that at environmentally relevant levels the mono-nitrogen oxide fraction of the exhaust gases was a key facilitator of this odour degradation. Such changes in recognition may impact upon a honeybee’s foraging efficiency and therefore the pollination services that they provide.
(a), A honeybee worker foraging on an oilseed rape flower (photographs by R Girling, C Reitmayer). (b–c), A honeybee worker (photographs by R Girling, C Reitmayer) restrained for a proboscis extension reflex (PER) assay with proboscis retracted (b) and extended (c). (d), The percentage of forager honeybees which, after learning the full synthetic floral blend, extended their proboscis (indicating recognition) when presented with the synthetic blend minus either α-farnesene (-αf), α-terpinene (-αt) or both chemicals (-both). The data are expressed as the per cent PER recognition of each blend relative to the PER recognition of the full synthetic blend (n ≥ 25), where on average 93% of forager honeybees learnt the full blend. Asterisks indicate a significant reduction in PER recognition of that blend in comparison to the full synthetic blend (P < 0.05).
Zur Studie auf Nature