Inter-dependent

 
Published: Thursday 31 August 2006

Less bees...
The plant, field scabious (Knautia arvensis), provides pollen and nectar to a wide range of insects. One visitor, the scabious bee, Andrena hattorfiana, raises her young only on pollen from this plant. The study showed a recent decline in the scabious bee species found in the UK and the Netherlands.

In addition, grazing and early cutting of hay meadows often prevent field scabious from reaching the flowering stage. The researchers explain that this may be a major cause of the decline of the scabious bee. Conversely, absence of the bee may have a role in the observed decline of the plant. In a Swedish study, the scabious bee has been shown to be a more effective pollinator of field scabious than other bees and hoverflies.

...less plants
Previous studies have shown that decreased use of wild pea species as fodder for farm animals has led to a decline of various bumblebee species. The current study shows that other species of wild bees that specialise in collecting pollen from wild peas, such as the longhorn bees (Eucera nigrescens, Eucera longicornis), are also declining. E nigrescens has become extinct in the UK and is very rare in the Netherlands. The researchers believe that this may be a result of a decline in some of their food plants (vetches, vetchlings and clovers).

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